Zfs sector size. 1 Drive has parity information.

Zfs sector size. Until this moment I've been blissfully unaware (or blatantly ignored Mar 30, 2025 · This guide explains how to run PostgreSQL using ZFS filesystem. There is no option Sep 16, 2023 · Choose the best recordsizeI have nvme drives for log,dedup and cache. e. What can I do to solve this? I was about to do the following for each drive, will it work? Mar 30, 2024 · The ashift 0 you get from zpool get simply means that on setup zfs tried to detect the correct ashift (as no value had been provided). Prettymuch anything since 2012 that supports 520 byte sectors will support 512 byte sectors if you know the right magic commands. There can be sector alignment problems on ZFS when a drive misreports its sector size. Which suggests that if such an alignment is not optimal, it will be good, suitable in most cases. Feb 23, 2018 · Today, I stumbled across a weird problem where I couldn't create a zvol, because ZFS claimed there was not enough space left, although there was enough space. For RAID5 4 drives each have a 4K sector of data. DESCRIPTION zpool remove [-npw] pool device … Removes the specified device from the pool. Sort of. As I understand it, it is much better (performance-wise and for disk/provider longevity) for the POOL sector May 18, 2019 · A commonly cited reference for ZFS states that " The block size is set by the ashift value at time of vdev creation, and is immutable. But you can safely set the sector size a small as the reported logical sector size. You’ve tried the usual sg_format I assume? Got a model number? Keep in mind that the recommended ZFS zvol block size for Linux is 128k, whereas it's 8k-32k under Solaris and variants. A sector represents the smallest read or write a disk can do in a single operation. 0 NVME: So, it looks like these are 512 bytes by default, but can support 4096 LBA size? Oct 3, 2022 · I have installed proxmox using the GUI Installer and missed what I believe to be an important setting for the sector size of the nvme disks. " In PVE, Datacenter>Storage lets me change the block size (I just did so on an online zfs pool) Then your nvme drives physical sector size is likely the largest "Data Size" listed. May 1, 2022 · Using a ashift that is smaller than the internal block size should show worse performance in benchmarks. But flash SSDs don't have sectors, the have "pages" for reading and "erase blocks" for writing, but anyhow all advertise 512B logical sectors. Mar 28, 2023 · Why? My opinion, because to ZFS the GELI GEOM "is the physical device"; to ZFS the underlying physical has a 4k sector size (ashift of 12 I think) and it all just works out. Is it right Mar 25, 2024 · I'm trying to add NVMe cache to several zpool that are set with ashift 12. This Calculate ZFS storage capacity based on your configuration, including pool type, number of drives, and redundancy level. Newer hard drives and SSDs use 4k sectors, but often emulate 512k logical sectors (called 512e) for compatibility. Overview Basic ZFS setup ZFS config ZFS ARC size ZFS recordsize ARC and shared_buffers TOAST compression Alignment Shift PostgreSQL full page writes PostgreSQL block size and WAL size logbias ZFS snapshots See also Overview The main reason to use PostgreSQL with ZFS 512/512 means ashift of 9, unless ZFS suspects that the drives lie, given that most SSDs that I have seen have sector size 512/4096. Top-level vdevs can only be removed if the primary pool storage does not contain a top-level raidz vdev, all top-level vdevs have the same sector size Jul 10, 2024 · Oversimplifying here, but ZFS does larger/smarter checksums (256-bit by default, 512-bit optionally) and then stores that checksum away from the data, so we can tell when things have gone missing or awry that way. Apr 23, 2024 · ZFS tracks disks’ sector size as the “ ashift ” where 2^ashift = sector size (so ashift = 9 for 512 byte sectors, 12 for 4KiB sectors, 13 for 8KiB sectors, etc. These drives are interesting in that they support dynamic switching between 512 byte sectors and 4096 byte sectors - which means that one can actually compare like-for-like performance with sector size! Oct 12, 2015 · Apart from possibly lower performance and greater overhead, the wrong sector size in ZFS shouldn't actually cause any real problems. If there was a "best" answer, it would already be set to this. g. 2TB SAS SSDs Jul 14, 2024 · From my measurements on my old nodes (ratio of “zfs plain file” objects cumulative size to everything else reported by the zdb) metadata takes 2. Oct 29, 2015 · Formatting today means initialising the filesystem; what exactly do you mean with 'format to 4k' or 'format to 512 byte' - that is not clear to me. Unfortunately they have 4096B sectors. When trying to add the NVMes (Micron_7450_MTFDKCC800TFS), the zpool status shows the following: status: One or more devices are configured to use a non-native block size. WTF does that mean? Imagine you have a ZFS volume with I dunno, "linux ISOs" only, about 1000 of them. Calculates capacity, speed and fault tolerance characteristics for a RAIDZ0, RAIDZ1, and RAIDZ3 setups. since zfs knows this, it instead will just write a 4b block directly to the drive, eliminating that read/change/write cycle. It also depends on the sector size and redundancy of meta data. Apr 16, 2014 · Hi, I'm about to set up a new ZFS based NAS with round about 24x 2. you can't format a ext4 with sector size 8k. Source: manpage of zpool No need to wipe the zpool as zdb reports the correct value, next time you setup a pool you may use zpool create -o Sep 19, 2020 · pool: mypool state: ONLINE status: One or more devices are configured to use a non-native block size. | Jun 3, 2020 · Hello, I'm creating new zfs pool (raid 1) And I have 2x Samsung 860 evo 512GB I know that proxmox like to write a lot of stuff to disks (my setup 45 gb per 24 hours average, all VM idling none of them writing to disks) And I didn't find any satisfying result about ashift for ssd. I assume downloading torrents to a pool with recordsize 1M would make the I'm building a new home server into which I plan on fitting a RADIZ2 four disk array running 16TB Seagate Exos X16 drives. where you see overhead with 4kn/512 mismatches is if you write 512 data to a 4kn drive, the drive must read 4kn, change 512b of it, and then write the 4b block. WD Green Mar 30, 2022 · Optimize ZFS recordsize for better performance. Nov 13, 2021 · Question: What sector size should I set for each of the following drives inside Proxmox (ZFS settings for pool)? Each pool is made of one type of drive. I've used nvme-cli to verify whether or not I could change it and the output shows that I cannot. Can you please let me know if any of the following is misguided? All of my drives have a logical sector size of 4,096 bytes - so my ashift should be 12 for all of my vdevs. Mar 1, 2025 · The Crucial supports 4K sector size (LBA), which can be selected via the nvme CLI tools or smartctl. 2TB 12Gbps SAS disks that have a 512 Native sector size. Expect reduced performance. . org. For create zfs pool ashift, use this: An ashift value is a bit shift value (i. Oct 30, 2023 · ZFS is about the most complex filesystem for single-node storage servers. Fortunately there is a way to convert these disks to 512 bytes block size using sg_format on either BSD or Linux. When creating VDEVs on these drives with the current version of TrueNAS, ZFS is using an ashift value of 12. ZFS is a Copy on Write system, which means that if you take a snapshot (or duplicate) a file and modify one byte, the modifications (min size of a record size) is created then (so 128KiB default). Extremely likely this will be 12 and also automatically detected. Aug 16, 2018 · Many of the aspects of the ZFS filesystem, such as caching, compression, checksums, and de-duplication work on a block level, so having a larger block size are likely to reduce their overheads. cannot replace /zfs_jbod/zfs_raid/zfs. If you have lots of small data but a large record size, space is wasted. The drives are marked 512e vs 4Kn which I understand means 512 emulated sectors and 4k native sectors. If you're building a big storage array, it's worth spending a little time to get this right. 1 Drive has parity information. ashift is a power of 2, so setting ashift=12 will result in 4k. It by default is formatted to 512B and you cannot make it go to 4k. Currently FreeBSD and its spinoffs support ZFS version 28. Note: Do not set the ashift property to a value that will assign a sector size larger than the device physical block size. Ideally this value should be set to the sector size of the underlying physical device (the sector size being the smallest physical unit that can be read or written from/to that device). If your vdevs are just single disks or mirrors, then 16k is a good record size for database and VM workloads, though you should still check how good the compression ratio is for larger record sizes. scan: scrub repaired 0B in 18:42:54 with 0 errors on Mon Sep 14 20:43:23 2020 remove: Removal of vdev 0 copied 1. Even if you replace a 512e/4kn disk with an older 512n one, zfs will account for that, and due to ashift=12 will still read and write to disk in 4k chunks, although now it has to be split in 8 requests of 512bytes. Logical sector size probably won't help (or even work), because AFAIK it is limited by the 4k page size on Linux, i. Question: Is there a performance benefit to configuring these drives to use 4K logical and/or tweaking the ashift value? Jan 6, 2023 · no. TLDR: Stick with the Feb 2, 2021 · If ZFS uses a 4K sector size on a disk with 512-byte sectors, the disk hardware breaks up the access requests into physical sector sizes, at very little performance cost. ashift=12) if adding This isn't ideal; you are probably better off with a full stripe fitting evenly into your RAIDz2 topology--for eight disks at ashift=12, you'd be looking for eight sectors per stripe minus two parity sectors for RAIDz, so six*sector size==>volblocksize=24K. Described as "The last word in filesystems", ZFS is stable, fast, secure, and future-proof. How do I remove it from there? I want to remove usb-Seagate_Expansion_NAAE7KF5-0:0 root@proxmox:~# zpool list NAME SIZE ALLOC FREE CKPOINT EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT rstorage 18. Normally, I select the largest/most performant LBA for an NVME before I put it in a ZFS pool with ashift=12, but in this case that’d mean mixing a 4K device with a 512K device. Drive Type 1: Sabrent Rocket 4. I'm going to destroy the vdev and create a new one with 8 x 4TB drives all of the same type. Partition #2 contains a xfs signature. The host only sees 512 byte sectors, for compatibility reasons. I tried with the nvme-cli tools and it only lists 512B as supported LBAs. ZFS will likely branch at version 28 in the very near future, so don't make your ZFS pool with any version greater than 28 unless you are 100% certain you want to stick with an Oracle solution. When I go to replace them zfs says that they're too small to fit. Mar 15, 2021 · Yep, 520byte sector size. Now, I am wondering, what block size should I be formatting them to? The physical block size is reported as 4160 I will be using them in a zfs pool on proxmox, so I am wondering if I should format them to match the physical sector size of 4160? or should I use the normal 4k, 4096 sector size? or should I format them to 512? Aug 27, 2022 · In Linux, logical sector size can be set using hdparm (according to stackexchange): hdparm --set-sector-size 4096 --please-destroy-my-drive /dev/sdX Is there a way to change a drive's logical sector size in TrueNAS? Would sg_format --format --size=4096 -v /dev/ada2 do what I want? Dec 19, 2023 · The examples below will assume you are doing this on Linux but ZFS commands themselves are universal. In a mirrored setup, data is duplicated across all drives in the mirror, ensuring redundancy. Nov 9, 2017 · Check the record size (with zfs list -o recsize watson/gelato) of both source and target. ZFS / RAIDZ Capacity Calculator (beta) RAID type: Drive capacity (GB): Drive sector size: Single drive cost: Number of drives per RAID group: Number of RAID groups: Aug 30, 2021 · For example: if we have a dRAID with 8 disks of sector size 4K, the minimum allocation size would be 32K, and this could be too big if the pool was to hold mostly smaller blocks, either because of the data itself or the use of ZFS compression. That seems to work well with the HDDs that I’m planning to use (WD Red Pro 20TB), since those have a physical sector size of 4096 bytes ( Internal Drive Advanced Format 4k Sector Size Support and Information ). And there should be a way to blast those drives back into 512B format, even if they’re SATA. 6% of the node used space. Apr 19, 2023 · Due to these inputs, if recordsize is less or equal to sector size, then RAIDZ’s parity size will be effictively equal to mirror with same redundancy. smartctl output follows. When the Drive is in 520 Bytes Block Size you will encounter problems with creating ZFS Arrays, Badblocks, mdadm failure due to the unsupported block size. 9 GiB. The problem is I seem to recall reading that the drives themselves A too small ashift will result in read-modify-write if the physical sector size is larger than the logical sector size, e. i'm creating zvols for iSCSI. In case of failure to autodetect, the default value of 9 is used, which is correct for the sector size of your disks. However, I searched it up, and it seems that there is a performance impact between ashift 9 and 12. The recordsize, on the other hand, is individual to each dataset (although it can be inherited from parent datasets), and can be changed at any time you like. I want to set it to 8k (ashift=13) and on another node to 32k (ashift=15?). 0 m. Hopefully that all makes some sense As we stated earlier, ZFS will operate a lot faster if it knows the physical sector size of your disk (s). if your pool consists of only 512 drives (512e or otherwise), you might as well set ashift to reflect that (ashift=9). The endurance of the disk likely will cut by 8x too. Thanks To unsubscribe from this group and stop receiving emails from it, send an email to zfs-discuss+***@zfsonlinux. Nov 16, 2017 · Here I see that each disk Sector size is 512 bytes / 4096 bytes, yet the hard drives is using sectors unit of 512 bytes, my question is should I choose ashift=9 instead of ashift=12 with this 4 HDD? I'm using this 4 HDD for a RAID10 with ZFS Internally, ZFS allocates data using multiples of the device’s sector size, typically either 512 bytes or 4KB (see above). Sep 11, 2021 · I have, in a server I’ve built, some new Exos x16 drives. Almost all harddrives and SSDs use 512 byte sectorsize, even though the harddrive uses 4KiB sectors and the SSD uses 8KiB pages. For example, for raidz1 of 3 disks with ashift=12 and recordsize=4K we will allocate on disk: one 4K block of data one 4K padding block and usable space ratio will be 50%, same as with double Dec 25, 2020 · Hi all 🙂 Currently waiting on hardware to get delivered. The NVME SSDs do not indicate a physical sector size but use 512 logical. Is there a reason not to do this? Match the NTFS cluster size to the volblocksize size. Should I use recordsize=1M for all my datasets, assuming no databases/vm images? The only caveat is you may have databases where you didn't realize you had databases. I have no idea what FreeBSD works best with. My test numbers were wrong (I retested with fio and it was much better around 100m/s) Jul 9, 2023 · Hi All, What should be correct ashift setting (9 or 12) on zfs pool with such disks: Disk /dev/nvme1n1: 1. I am not generally a fan of tuning things unless you need to, but unfortunately a lot of the ZFS defaults aren’t optimal for most workloads. But if you're doing a "NAS directory" for The logical ZFS sector size has two impacts: If it is smaller than the drive's physical sector size it will result in a lot of physical read-modify-write, which is very expensive. I destroyed that, and created a new tank: a 2-drive mirror, concatenated with another 2-drive mirror, concatenated with a non-redundant fifth device. How to reproduce: create pool with 1 mirror (2 part of hard drive), default ashift # zpool create vservers mirror wwn-0x5000cca097c66efd-part3 Online RAIDz calculator to assist ZFS RAIDz planning. Nov 26, 2021 · The default block size in PVE is 8k. 78T in 5h53m This is a complex issue, but in short: for avoiding poor space efficiency you must keep ZFS recordsize much bigger than disks sector size; you could use recordsize=4K or 8K with 512-byte sector disks, but if you are using 4K sectors disks then recordsize should be several times that (the default 128K would do) or you could end up losing too I recently formatted my Samsung 970 evo plus with a zfs filesystem, and the guide I was following said to set the ashift to 9. Recordsize. Apr 16, 2024 · ashift: ashift sets the sector size, ZFS should use. Tuning Record Size makes sense when the data is reasonably homogenous, in which case tuning the Record Size to the closest (ceiling) value of the median file size would be the way to go for minimizing fragmentation and maximizing read/write speed. I then proceeded to investigate using the CLI. When running smartctl -a /dev/nvme1n1 it shows a + next to 512, and the open-zfs docs recommend the disks should be formatted with a sector size of 4096 Mar 21, 2016 · Hello, I have a couple of questions. I know to add "ashift=12" when creating the vdev to make ZFS use 4k sectors (Proxmox taught me that). Im planning to set this at 4096, but couldnt set it at 8192 even if i wanted. Dec 29, 2021 · Having the drive sector size/page size match would allow zfs to issue 1 bigger write instead of 8 smaller ones and the drive would guarantee atomicity, which matters for sync write workloads you see in databases and journals, but it’s no big deal if it’s smaller. FYI if future disks have sector size above 512, you will not be able to do a straight ' zpool replace ' and will have to copy the data over to the ashift=12 pool Never mind. these disks have a sector size of "logical 512, physical 4096, offset 0" (as reported by "camcontrol identify"). in the case of 512e, the drive is emulating 512, so it's still just a 512 sector size disk as far as zfs is concerned, right? although obviously it's smarter to set ashift higher (i. The default recordsize is 128 KB, which comes to 32 sectors on a disk with 4 KB sectors, or 256 sectors on a disk with 512-byte sectors. I simply replaced the drive in the webgui. Going through everything the only difference I was able to find was that the Seagates had: a slack partition (Solaris reserved 1) of 64M sector count of "1953506646" While the WD Red's had: A slack partition size Jan 13, 2016 · - Dataset record size - ZVOL block size - ZFS compression - Logical block size in the iSCSI extent - NTFS/CSVFS allocation unit size used by the Hyper-V hosts for the CSV - NTFS allocation unit size used by the guest within the VHDX What is the best relationship between these values, are their optimal ratios or matching to be made? With the Jun 24, 2014 · This might occur for a variety of reasons and may have a significant performance impact depending on the device. Otherwise just make sure your ashift is correct, ashift=12 for 4K sector drives. Post ZFS get all output too, for ZFS gurus here! ZFS is an advanced filesystem, originally developed and released by Sun Microsystems in 2005. Nov 26, 2018 · I know that 4k Zpool sector size forget about the "zpool sector size" The main thing you get to tweak is the ZFS record/block size and this has (almost) nothing to do with the underlying drives. May 8, 2020 · ZFS 101—Understanding ZFS storage and performance Learn to get the most out of your ZFS filesystem in our new series on storage fundamentals. Question: If i set NTFS Blocksize to 64K, should i set ZFS Blocksize to 16K ? (4K Sector Size * 4 Raid-0 Mirrors ) 64K ? (same as NTFS Blocksize, which gets written as 4x 16K chunks to the NVME's and and split into 4 sectors on the NVME) My inkling is, that the 64K option is correct. For example, if you sector size is 4K, and the record size is 16K, this can work for 5 drives RAID5/RAIDz. I increased the disk size to 150Gb, but I can't seem to get the ZFS use the entire disk. The maximum recordsize was increased to 1 MB with the introduction of the large_blocks feature flag in 2015. Features of ZFS include: pooled storage (integrated volume management – zpool), Copy-on-write, snapshots, data integrity verification and automatic repair (scrubbing), RAID-Z, a maximum 16 exabyte file size Toshiba HDD Sector size (logical/physical): 512 bytes / 4096 bytes I/O size (minimum/optimal): 4096 bytes / 4096 bytes What ashift should I set for their pools? I was thinking ashift 12 for HDDs and 13 for the SSD. Oct 17, 2020 · In theory, ZFS will automatically set ashift to the proper value for your hardware; in practice, storage manufacturers very, very frequently lie about the underlying hardware sector size in order to keep older operating systems from getting confused, so you should do your homework and set it manually. I now wonder what would be a reasonable alignment. It turned out that a zvol obviously t Jan 13, 2025 · I understand that TrueNAS uses ashift=12, which means the sector size is 2^12 = 4096 bytes. Looking at my physical devices, all the vdevs have drives (including the accidentally added vdev drives) with 512 byte sectors, as per "diskinfo -v". Yeah, but you don't want larger single transfers from ZFS to be split up into multiple smaller transfers when it passes through GELI to the disk. There is a lot of misinformation out there. I've purchased several Samsung 970 Pro Plus drives and have discovered, now that I have them installed, that they report a physical and logical sector size of 512. Coming with its sophistication is its equally confusing “block size”, which is normally self-evident on common filesystems like ext4 (or more primitively, FAT). What should I do with it? Quick googling around shows the entire interwebs and their dog trying to hivemind how to reformat this and that drive pulled out of a server from 520 byte sector size to 512. Since you are a self proclaimed ZFS noob I would recommend FreeNAS. The physical sector size on disk is set by the ashift value at time of vdev creation, and is immutable. cache Jul 25, 2024 · Hi all, I have a 3 drive raidz pool with 3 8TB drives. 2T You can change the block size with ZFS easily, it is a supported function: sudo zfs set recordsize=[size] data/media/series This can be done at any time, but will only apply to new files. zpool replace -o a shift=9 pool olddisk newdisk Dec 9, 2021 · '~$ sudo zpool remove ch1 raidz1-1 [sudo] password for hs: cannot remove raidz1-1: invalid config; all top-level vdevs must have the same sector size and not be raidz. But this remains transparent (hidden) to the host. Apr 30, 2015 · Is there a sector size smaller than 4k that can be used with ZFS without a noticeable impact on r/w performance? While a 4k logical sector to match the physical sector provides the best performance, doing so compromises storage if you're storing many small files. Jan 24, 2023 · The installer in "Auto ZFS" mode sets the sector size to 4K by default. The ashift values range from 9 to 16, with the default value 0 meaning that ZFS should auto-detect the sector We used a 128 KiB block because that’s the ZFS default and what it uses for available capacity calculations, but (as discussed above) ZFS may use a different block size for different data. So 9 is actually 2^9 power, which is 512 bytes. Here are all the settings you’ll want to think about, and the values I think you’ll probably want to use. Is there any guidance for Windows File-Servers (think couple megs per excel ZFS / RAIDZ Capacity Calculator This ZFS / RAIDZ Capacity Calculator is designed to help you estimate the usable storage of your ZFS pool based on your configuration — including RAIDZ level, number of drives, drive capacity, and sector size. when i create extents for iSCSI i Apr 16, 2023 · When you are adding such device to a pool, override the sector size with the ashift parameter. The logical and physical block sizes can be read from sysfs: cat /sys/class/block/<dev>/queue/logical_block_size cat /sys/class/block/<dev>/queue/physical_block_size Categories: ZFS OSD Tuning Lustre Systems Administration I'm building a NAS using ZFS with Seagate drives (ST16000NM000J). Since most ISOs are probably way-bigger (800 May 1, 2024 · Hey peeps, I’ve bought a brand new Samsung Pro 990 nvme SSD only to now find out that the device does not support 4k Block sizes. May 3, 2024 · This shows the block size on the physical disk, not the block size of a file system like ufs or ext2-3 or ntfs (windows os). @coderonline, In case you don't know, "ashift" is ZFS' way of describing sector size. Suddenly I face dilemma. 512e drives. Unfortunately 2 of… ZFS using the disks natively allows it to obtain the sector size information reported by the disks to avoid read-modify-write on sectors, while ZFS avoids partial stripe writes on RAID-Z by design from using copy-on-write. OpenZFS switched the default to 16k, see here https://github. action: Replace affected devices with devices that support the configured block size, or migrate data to a properly configured pool. It’s possible to acquire SAS SSDs that are End Of Life (lol not really) for fairly cheap. Learn how it impacts workloads and how to fine-tune it for maximum efficiency in OpenZFS. May 4, 2022 · A sector is usually 4KiB but could be 512 bytes on older hard drives or 8KiB on some SSDs. Using the command "geom disk list" I was able to determine my drives are set up The recordsize property gives the maximum size of a logical block in a ZFS dataset. Firstly, I was of the understanding/belief that ZFS creates ZPools with 4096 bytes sector size by default, but I've just discovered that my array consisting of six HGST 6TB NAS drives is reporting 4096 bytes physical, but 512 bytes logical sector size. For the critical zpool, I purposely limited it to 4-drives to reduce my risk about as far as it will go - requiring 3-out-of-4 drives in a vdev to fail for a complete loss. Note: if the nvme id-ns -H command outputs multiple lines it means you can change the disks LBA size. When compression is enabled, a smaller number of sectors can be allocated for each block. Dec 20, 2018 · I have a ZFS pool that currently occupies 100Gb. While using a larger sector size does not impact performance, it does reduce space efficiency when you’re storing many small files. Since I have medium-like expirience with ZFS, I sure know about some trouble with the sector size of the drives. First, I've no idea what those sectors even mean. -o autoexpand=on if you want the pool size to auto-increase when you replace with larger drives or expand to a 4-disk config. 14 (AF) and report sector size 512-bytes logical, 4096-bytes physical. ZFS will attempt to ensure proper alignment by extracting the physical sector sizes from the disks. 2 with /dev/sdd1: devices have different sector alignment How can I change the partition sector size to be 512 like the others, or failing that is it possible to change the other pool devices to 4024 ? Mar 15, 2016 · From my understanding it would respect the physical sector size which for 512e drives that don't lie about it is 4k. I May 9, 2024 · By “record size” do you mean the logical sector size or physical sector size? Sector size of the disks, the VDEV or the pool? FreeBSD Mastery: ZFS indicates that when creating a pool, ZFS will set the POOL sector size to the largest sector size from amongst all pool member VDEVs. Jan 17, 2019 · I cannot find instructions around how to determine a vdev sector size (wouldn't this be the device's sector size?), and my pool is not raidz (it's a collection of mirrored pair vdevs). Dec 22, 2022 · when i try remove mirror-1 vdev i have error: cannot remove mirror-1: invalid config; all top-level vdevs must have the same sector size and not be raidz. Theoretically the disk is making it capable of doing 512k sector size but will I Jan 16, 2014 · How do I check that 4K blocks are properly set up for an existing pool? The drives are 4k but report 512 as the sector size. It is expressed as powers of two: ashift=9 means sector size of 2^9 = 512 bytes, and ashift=12 would be 2^12 = 4096 bytes. So recently I Apr 3, 2019 · About ZFS recordsize ZFS stores data in records—also known as, and interchangeably referred to by OpenZFS devs as blocks—which are themselves composed of on-disk sectors. Jun 6, 2020 · SSD Sector Size Traditional drives typically used 512k physical sector sizes. Record size is the size of data for each stripe across your vdev/RAID group. And 12 is 2^12 power which is 4096 bytes. The issue is why zfs thinks the real sector size is different. these are by default created with a "block size" of 16K. If you also need to install ZFS, see Installing ZFS on Ubuntu. Dec 9, 2022 · So if your data is compressible or if you have a lot of raid disks, you should raise the sector size to 32k or 64k even for databases. I have to replace two drives in my zfs pool made up of WD Reds 8TB drives and I got two 2 8TB Seagate drives. Dec 7, 2022 · NojuHD Thread Dec 7, 2022 #zfs ashift ashift deutsch sector size zfs Replies: 4 Forum: Proxmox VE: Installation and configuration Tags Apr 11, 2018 · In theory, ZFS will automatically set ashift to the proper value for your hardware; in practice, storage manufacturers very, very frequently lie about the underlying hardware sector size in order to keep older operating systems from getting confused, so you should do your homework and set it manually. Trying to remove the non-redundant vdev failed: cannot remove md4: invalid config; all top-level vdevs must have the same sector size and not be raidz. The enigma continues as ZFS bundles more optimizations, either for performance or in the name of “intuition” (which I would hardly agree). Each block With ashift=12, block size is 4096 bytes, which is precisely the size of a physical sector in a 512e disk. Most new disks use 4KB sectors to reduce plater overhead, (aka inter-sector gaps, and sector header & trailer). 5" HDDs. ZFS tracks disks’ sector size as the ashift where 2^ashift = sector size (so ashift = 9 for 512 byte sectors, 12 for 4KiB sectors, 13 for 8KiB sectors). Do I want ashift=9 or 12? My drives are Seagate Barracuda 7200. Dec 19, 2023 · I wanted to add a disk to my raidz1-0 but instead I added it to rstorage only. How do i force 4K sector size? When I run zdb | grep ashift I get ashift: 9. ZFS requires root privileges so either be root or use sudo/doas/etc Creating a ZFS Pool Identifying Drives When using drives for ZFS, you need to utilize their actual drive names or WWNs. I'm looking for a compromise Disk Sector Size (ashift) I'm setting up a file server with 4x Seagate Exos drives in a 2 x striped mirror configuration. I’m unsure whether I should be using 512 or 4K sectors when formatting these disk. Jun 25, 2014 · After some research, this is what I gathered about this problem: This happened because my drives misrepresent their sector size; My pool's ashift is 9 which doesn't align with my drives' 4K sectors; A pool's ashift can't be changed after creation. ' Mar 14, 2016 · 1) Is there any difference between 512e and 4kn from ZFS point of view and from drive point of view when ZFS reads/writes from/to it, that would justify 15%-20% for 4kN on top of what I would pay for 512e? Since ZFS respects the physical sector size of the drives if I use such 512e drives would ZFS do 4K only reads/writes to them? Mar 1, 2012 · We are trying to tune a zfs mirror running on a proxmox host for our database setup. So the best solution would be to have a separate dataset with small recordsize (4K per hdd) for active downloading torrents? And then moving finished files to the 1M recordsize dataset? I chose the small recordsize because of the copy on write design. IMHO, the chief issue you're fixing is aligning your minimum ZFS sector to the underlying hardware implementation because 512e mode on your drive is complete shit :-) OK, back to your question: why would variable block size be a benefit? The short answer is that block size is the minimum allocation size, while sector size is the underlying physical device sector size. For the zvol, it entirely depends on the anticipated access patterns. Or alignment or whatever. Maybe 12 for the SSD too? I'm not sure about that one, because I read somewhere that SSD's tend to lie about their sector size. 2 PCIe 4. For this reason, it may be safer to use recordsize=128K on your home directory, if this is a Linux or FreeBSD desktop (in case of SQLite or BerkeleyDB files you didn't know were there). Because of performance and replication considerations I was wondering, if switching from 512B to 4k blocksize (as used in most modern HDD) would result in a performance impact, so I ran some simulations. While you can create Pools with drive Sep 17, 2024 · ZFS infos ZFS (Zettabyte File System)ZFS infos ZFS (Zettabyte File System) Advanced file system that combines both file system and volume manager functionalities It offers features like data integrity checks, efficient storage, snapshots, compression, and more I use it on proxmox & pfsense, more or less on a default configuration ZIL (ZFS Intent Log) The ZIL records synchronous write Sep 26, 2018 · So a lot of cool hardware uses 520 byte sectors instead of 512 byte sectors (or 4* sector size in the case of SSDs). ). We also need to check for the sector sizes these drives support. A different block size will change the ratio of data sectors to parity+padding sectors so overall storage efficiency might change. - one of likely reasons why they made nvme/ssd logical sectors 512. Does ZFS care or pay attention to the logical sectorsize value? Or is it only the physical sector size that matters to a zpool? Does logical sectorsize only matter to higher level stuff like the filesystem? For instance if I was formatting regular ext4 directly onto the disk/hardware? Thank you to anyone that can clarify this for me. com/openzfs/zfs/pull/12406 Is there a reason why PVE doesn't do the Oct 5, 2021 · The SATA SSDs are 4K physical / 512 logical. Ashift must match your drive’s sector size. However, such concise answer fails to convey the true difference between block and sector size. In RAIDZ, the smallest useful write we can make is p+1 sectors wide where p is the parity level (1 for RAIDZ1, 2 for Z2, 3 for Z3). This command supports removing hot spare, cache, log, and both mirrored and non-redundant primary top-level vdevs, including dedup and special vdevs. May 23, 2020 · Using ZFS with the disks directly will allow it to obtain the sector size information reported by the disks to avoid read-modify-write on sectors while ZFS avoids partial stripe writes on RAID-Z by desing from using copy-on-write. 2 to the power of ashift), so a 512 block size is set as ashift=9 (2^9 = 512). Only difference I can see (including the sector sizes on Mar 7, 2022 · The NVME's Sector size is 4K 1. Jun 24, 2019 · But, at present I think the "ashift" value is pool wide. Apr 18, 2024 · Should I switch it to 9? Yes, rebuild the pool with ashift=9 for better performance. I am trying to get a better understanding of zfs/zvol recordsize vs zvolblocksize. additionally Aug 1, 2020 · In this article, Nick gives an introduction to ZFS which is a good place to start for the novice user who is contemplating ZFS on Linux or TrueNAS Mar 9, 2017 · I recently attempted to set up a freeNAS server and ran into problems creating the ZFS pool. For example, to add most SSDs as a L2ARC device, force 4096 sector size with this: (note 1 << 12 == 4096): zpool add -o ashift=12 pool1 cache ada0 Disable access time updates on the datasets holding storage node data: This removes associated IO: Mar 11, 2021 · In ZFS, ashift determines the size of a sector, which is the smallest physical unit to read or write as a single operation. To force 512 byte sectors use the ashift property which is described in the man page. This SSD is supposed to run zfs for hosting various virtual machines. The maximum block size ZFS is willing to write to the filesystem. ZFS will write to the drives in applicable ways for the sector size for the best efficiency. Aug 21, 2023 · The man page of zfs remove states: Top-level vdevs can only be removed if the primary pool storage does not contain a top-level raidz vdev, all top-level vdevs have the same sector size, and the keys for all encrypted datasets are loaded. So you for example could do 16K sequential sync writes/reads to a ashift of 9/12/13/14 ZFS pool and choose the ashift with the best performance. Since the drives seems to have a sector size of 512 should the ashift attribute be set to 9 upon zfs pool creation (ashift=9)? Btw: are there any other parameters I should set / change once the pool is created? Jun 2, 2022 · ZFS tracks disks’ sector size as the ashift where 2^ashift = sector size (so ashift = 9 for 512 byte sectors, 12 for 4KiB sectors, 13 for 8KiB sectors). If you use raw images on datasets or ZVOLs for your VM, you need to pass your recordsize/volblocksize at least as physical sector size to the VMs. If ZFS is set to a record size of 128k, the zvol is default to 8k, which one is actually used? Does the zvolblocksize Aug 17, 2018 · Quick and dirty cheat sheet for anyone getting ready to set up a new ZFS pool. Sep 24, 2017 · I have a vdev made up of 6 4TB WD Red WD40EFRX drives that have a sector size of logical 512 physical 4096. My ashift reported by zdb|grep ashift is 12, but that is not enough to determine that everything is working according to @Sebulon's post here May 5, 2024 · I got a Samsung 990 Pro NVME SSD, which by default reports a blocksize of 512B. First, note that the minimum write size for a RAIDz2 pool is 3 sectors (one for data + two for parity, since we must survive the failure of two disks). Feb 28, 2017 · hi, i have freenas box with 4 disks in RAID10 for storage. Partitions will probably end up aligned to 1 MB by default, which is fine because that also means that they're aligned to every power of 2 smaller than 1 MB too. But I just wanted to check what record size is best for storj? I was think 32k would be okay but what are you guys thoughts ? Jun 3, 2025 · ZFS RAID Levels and Drive Size Compatibility ZFS RAID 1 with Different Size Drives When configuring ZFS RAID 1, also known as mirroring, with drives of different sizes, it's important to understand how mirroring works in ZFS. Nov 28, 2022 · Hi all, Wondering what everyone would do? Would you use ashift 9 with a 512e sector size disk or go ashift 12? My understanding of zfs is still fairly basic but it is growing and im not sure what way I should go. I would like to figure out if there would be any difference between using 512e and 4kN drive with ZFS in vdevs created with ashift-12 and if ZFS would do only 4k reads and writes with such 512e drives. Configuring ashift correctly is important because partial sector writes incur a penalty where the sector must be read into a buffer before it can be written. Apr 19, 2020 · my take on this is you should set ashift to match the sector size. The purpose of this device is to host virtual machine workloads on the zfs filesystem. 46 TiB, 1600319913984 bytes, 3125624832 sectors Disk model: Micron_7400_MTFDKBG1T9TDZ Units: sectors of 1 * 512 = 512 bytes Sector size (logical/physical): 512 bytes / 4096 Dec 13, 2023 · As each sector in zfs will be 4096bytes in size, if its being modified it will have to use 8 real sectors on the disk. 512 is all these drives understand! I bought these for use in a fast zfs pool so my question is can I safely specify ashift=12 when Nov 6, 2015 · Hi, how can I set a different sector size for zfs on proxmox installation? As I read somewhere it's always set to ashift=12 aka 4k blocksize. ZFS tracks disks' sector size as the " ashift " where 2^ashift = sector size (so ashift = 9 for 512 byte sectors, 12 for 4KiB sectors, 13 for 8KiB sectors). Many database engines prefer smaller blocks, such as 4 KB or 8 KB Howdy, So I have a ZFS pool currently using 10 ST1200MM0108 Seagate 1. So I did some research on the HDDs I'm planning to use. For a new big node. Since they're Jun 1, 2023 · First sector (1000204616-2000409230, default 1000206336): ### I halved the number of sectors to make partition about 50% size Last sector, +/-sectors or +/-size{K,M,G,T,P} (1000206336-2000409230, default 2000409230): Created a new partition 2 of type 'Linux filesystem' and of size 476. My server was unable to format them to GPT or wipe them from the WebGUI. The HP only has 512K as an option. I would also suggest you create this as a single-disk pool to start with, (and definitely back it up on the regular) wait 7 days, and then attach the 2nd drive as a mirror. I’m trying to add 2 Optane NVMe drives for slog, but I’m getting this error: cannot add to 'tank': adding devices with different physical sector sizes is not allowed I have another proxmox system that’s functionally identical, 4 spinners in raidz, with 2 optane drives for slog. 2. Sep 14, 2023 · I wrote a detailed article about the technical details of how we backup but in essence we stream the ZFS volumes using zfs send and zfs recv directly to the RAIDz2 pool of our backup server. You'll lose NTFS encryption and compression, but ZFS can compress and you're not using NTFS encryption so that's not a problem. I have a the same exact issue yesterday with another serv Ashif/sector size is the sector size it writes to on each drive. LUKS2 lets you specify a --sector-size parameter, but only supports values ( 2 n ) between 512 and 4096 bytes. cxvq fdtveeg radsmnc siluhnb ypkys lche wrcd wuqti prewg xgs