Questions tagged [zfsonlinux]
zfsonlinux provides a native Linux kernel port of the ZFS filesystem so that ZFS may run natively on Linux. It is very different from ZFS-fuse which provides ZFS on top of a userspace-filesystem layer. The ZFS On Linux project is hosted on zfsonlinux.org.
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questions with no upvoted or accepted answers
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Restoring data after zfs destroy
On Debian 8.7 I had a zfs pool.
(obviously using ZFS on Linux, not Oracle or Solaris zfs)
It was needed to extend ZFS pool from mirror on 2 disks to raidz on 4 disks.
I did backup (one copy of data - ...
9
votes
1
answer
918
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Using ZFS head node as database server?
I'm using a dual-head ZFS-backed NAS for high availability cluster shared storage, based on Nexenta's recommended architecture as seen here:
The disks in 1 JBOD will store the database files for a ...
7
votes
0
answers
1k
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Recovering/importing ZFS Linux pool with duplicate pool name
I did something very stupid today in attempting to add a third mirror to an existing Linux zpool named backup. Suffice it to say that I made a couple errors because I don't really do much admin with ...
6
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0
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What is the easiest way to encrypt an existing ZFS dataset?
I would like to convert a lot of ZFS datasets I have on a (Ubuntu 20.04) server (about 3 TB of data). I've already tested this a bit, and what I've been doing so far is:
Create a new encrypted ...
4
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0
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Are the in-built sharesmb / sharensfs options in ZFS on Linux special/better?
While reading through the man page of zfs I noticed the sharesmb and sharenfs options. Are they thin wrappers over samba/smb/cifs/nfs provided by the underlying Linux system, or special/optimised code ...
4
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0
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307
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ZFS: usedbydataset value unusually large on one zpool
I have a 500T ZFS server with 8 zpools. The usage overall is pretty moderate. However, I noticed that on one of the zpools the usedbydataset value is as large as 24.2T. The actual user data on this ...
4
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0
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1k
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Docker Community Edition for production environment?
I was planning to use docker in a production environment. Now I see Docker Inc. differentiates strongly free and paid versions with the Community and Enterprise Editions. This sentence about CE is ...
4
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0
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796
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Any possibility to use ZFS for Samba4 AD DC share on Ubuntu 16.04?
For a few (~ 5) PCs running Windows 8.1 I have to setup a domain controller using Samba4 on Ubuntu 16.04 Server.
Additionally the DC should provide a few shared folders with user-specific access and ...
4
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0
answers
3k
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Grow ZFS pool to use the whole disk
What's the (if there's any) way to grow a zfs pool that only uses a disk partially to use the whole disk?
Background is, zfs is used here on a virtual machine and the Virtual machines disk has been ...
4
votes
1
answer
1k
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ZFS on LUKS not recognized at boot
I've got 6 physical drives in RAID-Z2, which I intend to one-by-one convert to dm-crypt devices.
My process was roughly:
dd if=/dev/zero of=/dev/sdf
Create keyfile /etc/crypttab.d/crypt-1.key
...
3
votes
0
answers
401
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zfs pool with slow speed on SAS drive with high latency
We have 3 servers in a gluster pool.
Each computer's spec is (Advance STOR-2 Gen 2 at OVH):
AMD Ryzen 7 Pro 3700 - 8c/16t - 3.6 GHz/4.4 GHz
6 x 14 TB disk (WD DC HC 530, using CMR technologies) ...
3
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0
answers
115
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ZFS missing filesystem after interrupted backup
I have two filesystems in a pool, backup/nextcloud and backup/vm. Today, after a send/receive transfer was interrupted before it could finish (I was backing stuff up to these filesystems), I no longer ...
3
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0
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193
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Is this disk about to die?
I have a WD Red 4 TB disk (WD40EFRX-68WT0N0, firmware 82.00A82) that is occasionally showing uncorrectable read errors in the SMART error log, e.g.:
Error 43 [18] occurred at disk power-on lifetime: ...
3
votes
1
answer
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ZFS keeps repairing the same disk when scrubbing - what does that mean?
I have a ZFS pool comprised of 6 disk, arranged in 3 stripped mirrors. The server is a Supermicro X11SSM-F with a Xeon CPU, 32 GB of ECC RAM running Ubuntu 17.04. I'm using 2 Icy Dock MB154SP-B to ...
3
votes
1
answer
1k
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ZFS doesn't want to detach replaced disk
I wanted to replace a disk in my zpool by issuing the following command:
zpool replace -o ashift=12 pool /dev/mapper/transport /dev/mapper/data2 ...
2
votes
1
answer
633
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Forcefully 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 ...
2
votes
1
answer
70
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ZFS: Replace raidz1-member of a striped pool for raidz2
I have a pool (in Ubuntu 20 LTS) like this:
# zpool status
pool: zpool_test
state: ONLINE
scan: none requested
config:
NAME STATE READ WRITE CKSUM
zpool_test ONLINE 0 ...
2
votes
0
answers
95
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zfs diff gives error on encrypted dataset (Key must be loaded to discover path names: Permission denied)
I'm running the following on Debian 10:
zfs-0.8.4-2~bpo10+1
zfs-kmod-0.8.4-2~bpo10+1
I have a 2TB (passphrase encrypted) dataset used by many colleagues. I am also using Zabbix for monitoring, and ...
2
votes
0
answers
553
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ZFS Datasets appear as empty when shared through NFS
I was trying to create a couple of NFS shares on my file server and failing miserably. After hours of trial and error I noticed that if I share a zfs dataset directly it appears as an empty folder on ...
2
votes
1
answer
896
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ZFS compression on sparce zvol - space difference
I'm compressing a dd img of a 3TB drive onto a zvol in ZFS for Linux. I enabled compression (lz4) and let it transfer. The pool just consists of one 3TB drive (for now). I am expecting to have 86Gigs ...
2
votes
1
answer
460
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Unable to remove drive in ZFS raidZ2
I believe I messed up in replacing a failed drive in my ZFS RaidZ2 pool. I think I forgot to offline the failed drive first and ran the replace command and now it seems to have created a temporary ...
2
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0
answers
766
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System freezes when syslog fills up with "java: page allocation failure"
Ubuntu 16.04 x64bit kernel 4.4.0
cpu:8 , memory:31G , ZFS is main filesystem and cifs share is mounted
# sudo numactl --hardware
available: 1 nodes (0)
node 0 cpus: 0 1 2 3 4 5 6 7
node 0 size: 32157 ...
2
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0
answers
900
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ZFS Faulted Pool Corrupted Data, resilver completed, incorrect paths, io error
I recently encountered a disk failure, for which I got a replacement disk, and successfully replaced the disk as well as completed the resilvering process. I was able to use the raidz2 without issues ...
2
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0
answers
1k
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How to share a zfs filesystem including it's child filesystems via nfs? Attempted approaches failed to share child filesystems
How to share the whole zpool (including child filesystems) via nfs?
Using the belowzfs filesystems:
NAME USED AVAIL REFER MOUNTPOINT
backup 7.22T 6.83T 3.94T /backup
...
2
votes
2
answers
7k
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zfs module not found on centos after restart
After I rebooted a CentOS server, ZFS does not work:
$ sudo zfs list
The ZFS modules are not loaded.
Try running '/sbin/modprobe zfs' as root to load them.
$ sudo modprobe zfs
modprobe: FATAL: ...
2
votes
2
answers
82
views
Removed ZFS files reoccurring after remount
I have a nasty situation with some of my ZFS filesystems (see list below). Files I removed therein keep reappearing after a remount (such after a reboot). One such filesystem is /root. I get an mount ...
2
votes
0
answers
824
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Best practice for setuid and setgid in /root and user directories
ZFS allows to created datasets with setuid turned off, which (AFAIK) means that setuid bit can't be set on files stored in those datasets.
Assume now that there are two datasets, one for the /root ...
2
votes
1
answer
2k
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How to import a child of a broken zpool mirror on a different host?
I have a hard disk lying around which once belonged to a 3-disk ZFS mirrored pool on a Ubuntu 12.04 server, called d510. The disk was properly detached but its filesystem tank0 was not exported.
I ...
2
votes
1
answer
1k
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Access iSCSI block device, setup as ZFS volume on CentOS7 - won't automount on boot, hangs on reboot
I am running CentOS7 on a virtual instance at Softlayer. There is a block storage device available to the instance via multipath/iscsi
I have successfully had this block device mounted as XFS. I ...
1
vote
1
answer
613
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ZFS on Hetzner Rescue fails with `checking whether inode_owner_or_capable() takes user_ns... configure: error:`
Normally, when booting into the Hetzner rescue system, using the 'zfs' command will automatically install zfs tooling inside the rescue system.
This is currently not working;
checking whether ...
1
vote
0
answers
586
views
On Linux ZFS Server - What is eating my memory?
Our monitoring tool regularly reports low memory for one of our servers running ZFS.
# free -g
total used free shared buff/cache available
Mem: 125 ...
1
vote
0
answers
237
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ZFS/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 ...
1
vote
1
answer
386
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ZFS send/recv full snapshot
I have been backing up my ZFS pool in Server A to Server B (backup server) via zfs send/recv, and using daily incremental snapshots.
Due to hardware issues, the ZFS pool in Server A is now gone - and ...
1
vote
2
answers
813
views
How can one recover/write a label (clone existing one)?
ZFS stores 4 labels, 2 at the beginning of a device, 2 at the end. When they are corrupted a pool cannot be mounted.
I had a case of 3 broken labels (failed to unpack), but 1 was still intact. I could ...
1
vote
0
answers
371
views
ZFS disk error on write
our ZFS backup pool is producing strange disk errors when writing data. This pool is replicated via DRBD on a second server with identical hardware which is also experiencing the same errors. This is ...
1
vote
1
answer
2k
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Linux mountpoint can not be unmounted no matter what?
I have a mount point in Linux that does not show any open files in lsof or fuser. The mount point was exported in NFS, but is no longer exported, and there are no more files or directories in the ...
1
vote
0
answers
1k
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How to boot ZFS root filesystem after setting dnodesize = auto (making grub unable to read the disks)
I have a proxmox (v5.4 I think) installation on top of ZFS in a server with 6 disks. There are 2 pools: rpool in a mirror of two SSDs that has the proxmox root filesystem and some containers and zvols....
1
vote
0
answers
243
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Should I partition or format a disk before replacing a FAULTED disk in a ZFS pool?
I recently had a FAULTED disk in a ZFS pool and wanted to replace it. I simply put the disk in and let it resilver. Afterwards, I noticed the disk was partitioned differently than the other disks and ...
1
vote
1
answer
2k
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Pool gone with upgrade to Ubuntu 20.04
I upgraded my server (SuperMicro X11-SSM-F, LSI SAS 9211-8i) from Ubuntu 18.04 to 20.04. The server had 2 zpools, one composed of a single WD Red 10 TB (downloadpool), and the other composed of 8 WD ...
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0
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ZFS issue after enlarging image
I created a new img using the following command:
truncate -s 250G disk.img
and I replace the existing image that I used for zpool with that one using (lxd.img was 2G):
zpool replace lxd lxd.img ...
1
vote
0
answers
547
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Why ZFS ARC hit rate is higher than real performance hit?
We've got Debian Wheezy host with ZFS on Linux with in.
It is used only for serving large files over http.
User activity is mostly characterized by a lot of random read.
We've noticed that ~95% ARC ...
1
vote
0
answers
518
views
zfs pools unavailable, disks shared with other pools
My ZFS pool called data do not mount anymore after a shutdown.
Maybe there was some automatic update on the computer. I Don't know.
zpool status returns
no pools available
zpool import returns ...
1
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0
answers
3k
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Formatting a FreeNAS ZFS volume as ext4 for Linux use?
I've setup a FreeNAS server with 6x 3TB drives for use as a backup NAS via iSCSI for a Linux server (Ubuntu 12.04). The FreeNAS setup was pretty straightforward and the logical step seemed to be to ...
1
vote
1
answer
732
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ZOL vs zfs-FUSE
I run a server using 5 drives in a raidz2 through zfs-fuse, but sometimes encounter an issue where the pool becomes unavailable. The issue seems to co-inside with high levels of activity on the pool, ...
0
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0
answers
29
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Access to ZFS pool when one drive has failed is incredibly slow
I have a ZFS box that I inherited that is having a lot of issues. Checking the status I see there are a few drives with issues:
ganymede $ zpool status -x
pool: dpool
state: DEGRADED
status: One or ...
0
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0
answers
32
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/dev/zvol/pool/group/srv points to partition zd0p16 not volume zd0 - bug or feature?
I am only starting to get familiar with openzfs 2.2.0 on Linux (Ubuntu kernel 6.5) and immediately ran into something strange. A symlink I was expecting to point to a zvol block device.. was pointing ...
0
votes
1
answer
36
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zfs force import multiple VMS (IDs) and now can't find VM but it's not missing according to zfs?
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 ...
0
votes
1
answer
290
views
ZFS I/O Error, Kernel Panic during import
I'm running a raidz1-0 (RAID5) setup with 4 data 2TB SSDs.
During midnight, somehow 2 of my data disks experience some I/O error (from /var/log/messages).
When I investigated in the morning, the zpool ...
0
votes
2
answers
120
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How does zfs know which snapshots to send with the `-I` flag?
From the manual:
A group of incremental snapshots can be combined into one snapshot by
using the zfs send -I option. For example:
# zfs send -I pool/fs@snapA pool/fs@snapD > /snaps/fs@all-I
How ...
0
votes
0
answers
105
views
Persistent ZFS pool errors on Ubuntu, even after repeated scrubs
My 3-disk ZFS pool has been scrubbed several times after replacing failing disks.
"zpool status -v" provided a list of files which were deleted and removed a good number of errors.
Despite ...