Are ZFS Automatic Spares Size-Aware when Using "autoreplace=on"?
Max ZFS codebase for pool: zfs-linux (0.7.5-1ubuntu16.11)Imagine a pool that grew unexpectedly, by adding larger mirrors in terms of physical disk capacity. Spares went in tow. New mirror, new spare....
View ArticleBooting a Debian Live ISO on QEMU
Situation:A server:access only via SSH (no physical access, no KVM)a netboot OS (Debian/Jessie)3 x 2T HDD16G RAMFinal goal:Building a ZFS pool with the local HDD and install Debian on a ZFS root, the...
View ArticleNo files after send/receive of snapshot between systems
I have two separate systems, prime and alt, on the same network in the same rack:prime 192.168.0.100alt 192.168.0.101Each system has a zpool running on it, created with the following sequence:>...
View ArticleDoes zfs zfs recv validate checksums?
It seems that zfs send includes a checksum for all included data (stated for instance here). Is this checksum automatically verified by zfs recv? I would assume it is, but I cannot find any...
View ArticleZFS/ZoL: Consequences of increasing zfs_vdev_async_read_min_active (and max)?
Vdev async read queues have min=1 and max=3 by default. All sync read/write queues are defaulted to min=max=10, while async writes get min=2 and max=10.Async reads are described as "prefetch reads" in...
View ArticleHow to remove a device from a ZFS pool? [duplicate]
I wanted to add ata-TOSHIBA_DT02ABA400_90D1S0Q2S75H into the raidz1-0. Running zpool add tank ata-TOSHIBA_DT02ABA400_90D1S0Q2S75H unfortunately it becomes:$ zpool status pool: tank state: ONLINEconfig:...
View ArticleZpool permanent error for raidz2
Problem: Zpool shows "errors: Permanent errors have been detected in the following files: tank/vms/fileserver:<0x0>Server has six 12Tb drives in a raidz2. These are spinning drives.Zpool shows...
View Article.zfs folder's missing, but snapshots are still there and mountable (inode...
$ sudo zfs list -t snapshot | grep childDataset3a whole bunch are listed as expected (e.g. pool/dataset/childDataset3@today)$ ls /pool/dataset/childDataset3/.zfsls: cannot access...
View ArticleZFS checksum error: how to recover from a replica?
ZFS can automatically repair checksum errors if the drive with the error is part of a pool set up with redundancy.What about the case when the checksum error is on a pool without redundancy, but there...
View ArticleHow can I list what zfs compression algorithms are available?
I have a zfs pool on a production system and I would like to see if it's possible to use zstd compression instead of the current gzip setting.Is there any way to list available compression options?
View ArticleZoL+FIO Randwrite nvme bs=8k@32io = 148MiB/s?
Sorry for the title, but it's very short summary of BS that I'm looking into. SituationI'm using ZoL 2.1.5 (from jonathonf's ppa) on Ubuntu (tried 20.04&22.04)I have following NVMe diskKingston...
View ArticleIs it possible to repair a ZFS snapshot by re-sending it?
Given two ZFS pools where snapshots from one are sent to the other, is it possible to automatically repair a damaged snapshot using a copy of that snapshot stored on the other pool?I'm hoping this will...
View ArticleRecreate Dataset Without Any Data?
I have some datasets that are frequently written to, but whose data is non critical (caches etc.). Is it possible to "send" these to another pool without copying any of their data?I realised too late...
View ArticleZFS: Suppressing reservation on receiving side?
I'm trying to incrementally send changes for a zvol from my working pool (zdata) to a backup pool (zbackup), however I'm struggling to suppress the refreservation property.While I realise that the...
View Articlersync "Operation not supported" errors for ACL on ZFS
While migrating our file server to a ZFS file system with rsync -avxHAXS ... I get errors like:rsync: [generator] set_acl: sys_acl_set_file(path/to/file, ACL_TYPE_ACCESS): Operation not supported...
View ArticleForcefully forget / unmount ZFS pool after drives disconnected
First off, I made a mistake & I acknowledge that, but now I'm stuck with a "broken" ZFS driver and want to restore it without rebooting my machine.How I can say ZFS on Linux to just forget the...
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Tuning ZFS for bursty sequential writes
This is a follow-up to: High speed network writes with large capacity storage. The setup has changed notably.I have a pool with a single raid-z2 with 6 drives, all Exos X18 CMR drives. Using fio and...
View ArticleWhy doesn't ZFS vdev removal work when any raidz devices are in the pool?
First: I'm perfectly okay with accepting that this is the case for now and am not looking for an immediate solution, rather I'm trying to understand the technical limitation for this constraint.I'm...
View ArticleWhat ZFS pool, vdev and dataset properties should most people use?
ZFS has many different configurable properties for pools, for vdevs and for datasets. Many of those can be changed at any point, but some can only be set at creation time (or only affect data written...
View Articlezfs force import multiple VMS (IDs) and now can't find VM but it's not...
I'm completely new to ZFS. Today, I did something stupid and caused a problem where I need to recover my entire OS. On a live OS I'm using to recover my machine, I need to mount my ZFS volumes for data...
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dRAID, Parity 1 + 1 Distributed Spare Better than basic RAIDz2 for 5x12TB HDDs?
Stumbled on dRAID recently and was grokking the docs for OpenZFS on linux and I came away with a conclusion from the chart that I wanted to double check.This is a brand new system that I'm currently...
View ArticleZFS performance: Extreme low write speed
I am running a small home server. The specs are:CPU: AMD Ryzen 5 2600RAM: 32 GB ECCSystem drive: 128GB NVMe SSDData drives: 3x 4 TB Seagate Barracuda HDDThe server runs some applications like Nextcloud...
View ArticleZFS silently overwrites the later mirrored devs, without any logs?
Given two mirrored drives:/dev/loop1 of zfs1.img/dev/loop2 of zfs2.imgIf the drives contain different data, even if the copies in zfs2.img are newer, or zfs2.img contains extra files, ZFS always...
View ArticleSyncthing on ZFS a good case for Deduplication?
I've have a ext4 on LVM on linux RAID based NAS for a decade + that runs syncthing and syncs dozens of devices in my homelab. Works great. I'm finally building it's replacement based on ZFS RAID (first...
View ArticleWhat are potential dangers of spanning ZFS RAIDZ over different size disks?...
I am redesigning my homelab servers from scratch, and want to try ZFS after experimentation I've done.I know there is a limitation that disks in vdevs must all have the same size, otherwise only the...
View ArticleErasing Contents of a Parent Dataset Without Destroying Children?
I have a parent dataset under which are stored a number of other datasets that are still in use. In the past I also used the parent itself to store data, as it was part of a directory...
View Article"No L2ARC Here" but cache disks are present in ZFS
I replaced the cache disks on my ZFS server and everything seems fine to me:$ zpool status pool: storage state: ONLINE scan: scrub repaired 0B in 1 days 09:44:40 with 0 errors on Tue Jan 21 17:50:23...
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