Questions tagged [zfs]
ZFS is a modern file system and volume manager originally developed by Sun Microsystems and licensed under the CDDL. It is a copy-on-write file system with support for large storage arrays, protection against corruption, snapshots, clones, compression, deduplication and NFSv4 ACLs. An open-source fork of ZFS can be found at http://open-zfs.org/ , which is supported by ZFSonlinux.org, illumos.org and ZFS developers in the FreeBSD & Mac OS X communities.
1,465 questions
3 votes
1 answer
88 views
ZFS fails to allow mount for user
I use zfs allow so a user can create and mount a dataset. But ZFS only allows the create operation. Can anyone provide insight as to why this should not work? As superuser: root@gem:~# modinfo zfs | ...
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6 votes
1 answer
646 views
Reduce speed of zfs scrub
I have a zfs pool with some NVME devices. In normal usage of that pool over network, the network is limitting IO and everything stays cool and quiet. But when I do a scrub it goes with max IO of the ...
- 161
1 vote
2 answers
220 views
ZFS: slow read of empty sparse zvol
I'm using RAID-Z2 with 8x8TB disks. Pool almost entirely empty. I created a zvol like this: zfs create -V 1T -s -b 4096 "$ZVOL" zfs set compression=off "$ZVOL" zfs set logbias=...
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1 vote
0 answers
96 views
Write Errors SAS SSD with Adaptec ASR-71605 Controller on Supermicro Server
I am stumped about what might be causing some sporadic write errors I've been seeing after making a change to my file server, hoping someone here can help narrow down the root cause. My first ...
7 votes
1 answer
624 views
Horribly messed ZFS pool after power cut
After a hard power cut and a UPS failure y ZFS pool is in a state I cannot understand: $ zpool status -c serial pool: storage state: DEGRADED status: One or more devices could not be used because ...
- 523
2 votes
0 answers
190 views
Cannot unmount with zfs unmount or umount after zfs receive
Running TrueNAS SCALE 24.10 I did a zfs send and receive with a -F on receive zfs destroy fails because it cannot unmount zfs unmount fails with unmount failed umount fails as well with not mounted. A ...
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0 votes
0 answers
26 views
Mount a non encrypted ZFS partition from a backup on another FreeBSD system
r@bsd:~ $ geom disk list Geom name: cd0 Providers: 1. Name: cd0 Mediasize: 0 (0B) Sectorsize: 2048 Mode: r0w0e0 descr: QEMU QEMU DVD-ROM ident: (null) rotationrate: unknown ...
- 433
0 votes
0 answers
69 views
zfs/zpool - how to remove hole in vdev_tree?
I have a zpool in use with a single mirror vdev. I needed more space, so I hooked up some more disks and added a second mirror vdev. Easy enough, now I have a zpool with mirror-0 and mirror-1 vdevs. ...
- 111
0 votes
1 answer
133 views
upgrading zfs-linux with active zpool and /home mounted to it
I am running zfs-linux on a Linux Mint (LMDE 6) machine for maintaining a RAID-Z2 storage. The home directory is its own dataset with mountpoint=/home. zpool/home cannot be unmounted by non-root user. ...
- 33
2 votes
1 answer
143 views
Import ZFS with faulted device, missing ZLog and corrupted data on a foreign System
I have an Ubuntu 24.04 Server with 4x4TB SSD in a Raid5, an additional NVME as ZIL. Now, for unclear reasons, the server became unbootable and I plugged all disks into another Server. I still cannot ...
- 156
1 vote
0 answers
54 views
ZFS array experiencing errors after hardware upgrade
I upgraded the system board, CPU, and RAM of our main server. The server does weekly scrubs and twice weekly backups to the backup server. I created a fresh snapshot and pushed it to the backup server ...
- 215
0 votes
0 answers
78 views
Upgrade ZFS from 0.8 to 2.3.0 version
I'm going to upgrade an old server from ZFS 0.8 to version 2.3.0 and want to clarify a few key points before proceeding. If anyone has experience upgrading from 0.8 to 2.3.0, I’d greatly appreciate ...
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0 votes
0 answers
88 views
ZFS Pool FAULTED - The pool cannot be imported due to damaged devices or data
Ive been recently testing/running zfs with no issues until today when carrying out some scheduled server maintenance (reboot) to find the pool has faulted upon reboot. Ive tried to force import but i ...
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1 vote
1 answer
392 views
How to backup Truenas Core (ZFS) snapshots to S3
I am happy I just setup a cloud sync task on my Truenas Core to S3. All seems good. However, I understand this is merely a filecopy/sync task and doesn't it make more sense to use the ZFS superpowers ...
- 93
1 vote
0 answers
50 views
Docker stuck on zfs clone
I have a /var/lib/docker on zfs dataset, and docker create many legacy datasets. Now when I try to start any app in docker it stuck on zfs clone. on iostat disk don't have any load (other dataset on ...
- 21
0 votes
1 answer
91 views
zfs recv keeps trying to make another subpool with the same name on incremential snapshots
I'm having a weird issue with zfs incremental snapshots. Let's say I have the following volumes. kirssy is the backup for abby: NAME USED AVAIL REFER MOUNTPOINT abby ...
- 1,140
3 votes
1 answer
334 views
Should datasets be mounted inside directories in ZFS for Linux?
On my recently set up machine I use ZFS under Linux Mint (LMDE 6) for creating storage pools and using the ZFS filesystem. The specific storage setup is four 1 TB HDD arranged in RAID-Z2 topology. The ...
- 33
3 votes
1 answer
431 views
Mounting ZFS drive with Proxmox
I am being challenged with an encrypted hard drive that is not mounting on Proxmox. The drive is LUKS encrypted and it is a ZFS file system. The name of the drive in question is /dev/sdc It is worth ...
1 vote
2 answers
318 views
Why does calling chown and chmod that does not change anything create differences between snapshots on ZFS?
On our server we have got a cron job that regularly calls chown and chmod for a directory in a ZFS file system. Usually that does not change the user and the rights because the directory already has ...
- 629
2 votes
1 answer
908 views
Rollback to a previous proxmox snapshot without losing the current zfs snapshot?
Using proxmox with ZFS storage pools, is it possible to restore an LXC container or QEMU Virtual Machine to an earlier snapshot (not the most recent snapshot) without losing or destroying any ...
- 9,408
2 votes
0 answers
316 views
How to replicate ZFS-based PVCs created by OpenEBS LocalPV CSI across nodes for disaster recovery?
I have a multi-region, bare-metal Kubernetes cluster that uses Tailscale and flannel for cross-node networking. For storage, I’m using the OpenEBS LocalPV ZFS CSI driver on two specific worker nodes, ...
- 21
0 votes
0 answers
141 views
ZFS RAID 10 on Ubuntu 24.04: Issues with /dev/disk/by-id/
I'm having a small issue with a Github Repository that I created. The intent of the Repository was to automatically install Ubuntu 24.04 on a ZFS RAID 10. I chose ZFS RAID 10 as this is meant to ...
2 votes
1 answer
175 views
Does ZFS have persistent inode numbers or something similar?
I am wondering if ZFS has persistent inode numbes for files, like EXT does, or if it has something similar with which individual files can be identified even if they are moved or renamed. And will ...
0 votes
0 answers
123 views
How to remove a vdev device from a Solaris 10 ZFS pool
I added a disk to a Solaris 10 server and was trying to add the device to an existing single disk pool as a mirrored device however, instead of using the "zpool attach tank c1t5d0" command, ...
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3 votes
0 answers
83 views
How to move a *deduped* ZFS filesystem from one pool to another
I have a ZFS filesystem which uses dedup [1]. I'm trying to migrate it to a different pool by using zfs send | zfs receive (as described in Moving a ZFS filesystem from one pool to another for example)...
- 1,018
5 votes
1 answer
167 views
OOM after files remove with ZFS and deduplication
I’ve encountered a serious issue with my ZFS testbed. When I write a large amount of data (four 2TB files) and then attempt to remove them using the rm command, the RAM usage quickly spikes, causing ...
- 51
11 votes
2 answers
692 views
How can I tell which ZFS snapshots are affected by an error?
A recent scrub of my ZFS pool uncovered one error: $ zpool status -v rpool pool: rpool state: ONLINE status: One or more devices has experienced an error resulting in data corruption. ...
- 649
5 votes
2 answers
177 views
ZFS-pool without striping to be used within VM-images?
I'm going to setup a VM, starting with two disks, one for / and one for the data using a ZFS-pool. Don't want to create VM disks too large, even in case of dynamically growing ones, and prefer chunks ...
2 votes
0 answers
344 views
Reimport a ZFS pool that has not correctly been exported
I recently bought a QNap NAS and decided to try out a few NAS OS, amongst which TrueNAS. After creating a ZFS pool on TrueNAS and transfering a few files, I got disatisfied with TrueNAS and decided to ...
- 129
4 votes
1 answer
207 views
Erasing 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 hierarchy. ...
- 427
3 votes
1 answer
98 views
If I'm using compression with ZFS can I somehow request the compressed version of the file without decompressing it first?
Now that Zstd is slowly getting support in the browsers I'm wondering if I could keep my Zstd compression and forwarding the files as is with ZFS. Currently as far as I know ZFS implicitly ...
- 135
0 votes
1 answer
517 views
Corrupt zpool disks not being discovered. How do I rebuild?
I have a Proxmox server with a few zpools. One of the zpools rust01 is a 4-disk zpool, where the metadata and write cache were some nvme m.2 drives on the motherboard (one for each - I know, stupid, ...
- 249
1 vote
1 answer
304 views
COW filesystems (BTRFS, ZFS, bcachefs) scrubbing and RAID1 with mdadm on Linux
Suppose I create a two disks RAID1 volume with mdadm and then create a BTRFS/ZFS/bcachefs partition on it. Than data on one of the two disks gets corrupted. If I perform a scrub, there's no way for ...
- 113
1 vote
1 answer
96 views
zfs, possibly bad performance
I am looking to confirm if this behaviour is normal as I got a new server and I am testing some SQL queries and they seem to be slightly slower than on the old machine. This is freebsd 14.1 When I ...
- 23
3 votes
1 answer
205 views
What are potential dangers of spanning ZFS RAIDZ over different size disks? [closed]
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 ...
- 271
2 votes
1 answer
304 views
ZFS import unable to find any pools on RockyLinux after Reboot
I had a single ZFS pool comprised of 8 (6/2) drives in a ZFS pool and after my server was down for ~5 days of no power the zpool I had created no longer shows where I mounted it. When I first access ...
- 23
1 vote
0 answers
270 views
Is it possible to change zfs raid-z1 to raid-z2 or raid-z3 on for instance TrueNas scale
I have a running truenas-scale zfs on raid-z1. For safety I though of increasing parity when adding a new disk. Asking the same question as someone asked 10 years ago, is it possible with the current ...
- 113
0 votes
0 answers
122k views
Cannot send snapshot XXX recursively: snapshot dataset/nestedDataset@XXX does not exist
I performed a snapshot pruning 2 days ago that resulted in some issues on the snapshots. I incurred some light data loss because, I suspect, some snapshots were created as "clone snapshots" ...
1 vote
1 answer
52 views
How to get IP details of passive cluster?
I have Sun Oracle ZFS storage ZS7-2 model. It is a 2 node cluster active and passive. Unfortunately I have only active node IP details to login. Can anyone help me on how to get passive node IP ...
siva swamy
4 votes
1 answer
109 views
Comments on new SAN for small enterprise
We currently have 4 FC arrays containing sixteen 300GB drives each in a Sun StorageTek 6140 chassis connected to an old Sun X4170 M2 server running OpenIndiana. This has been working well for the past ...
2 votes
0 answers
89 views
How to set a quota on Logical Disk Space (logicalused) in ZFS?
I am currently using ZFS and need to set a quota on the logical disk space (logicalused) rather than the physical disk space used after compression. The quota and refquota properties in ZFS set a ...
- 143
5 votes
2 answers
899 views
ZFS Kernel Panic Issue and Troubleshooting Steps
Experiencing kernel panic with the error message "PANIC: zfs: adding existent segment to range tree" when attempting to import the ZFS pool (rpool). The system hangs upon import attempts, ...
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2 votes
0 answers
257 views
0 votes
0 answers
284 views
Data corruption in Windows Server VM on Proxmox
I ran into a strange data corruption issue in a VM running on Proxmox VE which I need help with. The VM in question is Windows Server 2016 Standard, used primarily as a file server. On this VM, I ...
1 vote
0 answers
188 views
ZFS: resilver restarted after the scan finished
As described here I had two dead drives on my raidz2 setup. I shut down the machine, replaced one drive, then booted up. My idea was to resilver disks one by one, but the resilver process for the ...
- 523
3 votes
2 answers
826 views
ZFS folder very slow after having many files
I am running Ubuntu 24.04 using ZFS for my filesystems. This is on a laptop whose only storage device is a WD Black SN850X NVMe card. The default Ubuntu installation process configured two ZFS pools: ...
- 301
2 votes
1 answer
227 views
ZFS "cannot open" and "too many errors"
I got an alert this morning that one of my arrays was having a problem. I can't seem to get past it. I'm not sure how to proceed. admin@ICSSAN1:~$ zpool status -v pool: SAS_Array state: UNAVAIL ...
- 21
1 vote
1 answer
459 views
How I do recover from an offline, but OK drive on a ZFS mirror?
I have a ZPool consisting in two drives in a mirror configuration. It seems that during server manteinance (cleaning), one of the drives went offline because the wiring came lose. # zpool status -v ...
- 111
1 vote
1 answer
173 views
ZFS disk replacement identification?
I am still a newbie with ZFS. We had a faulty disk in a ZFS pool (using Ubuntu 22.04.2. LTS). It had been replaced automatically by a spare disk (I try to quote only the relevant parts): zpool status ...
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1 vote
0 answers
97 views
ZFS ARC ghost memory usage
Are arcstats:mru_ghost_evictable_metadata and arcstats:mfu_ghost_evictable_metadata the number of bytes stored in RAM by the arc ghost list? If so, is this memory usage also accounted for in the ...
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