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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Getting Ubuntu 16.04 on a ZFS root on a Hetzner dedicated server

By now, it's well possible to get Ubuntu 16.04 running on a ZFS root-fs. Ubuntu 16.04 has ZFS in the default package manager, and with guides like this, it's not hard to get started. However, all ...
TinkerTank's user avatar
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How to change default zfs options of a zpool?

How do I change the default options for zfs filesystems on an existing zpool? That is, ZFS stored for each zpool pool the default values for new zfs filesystems. Those are then used by zfs create as ...
vog's user avatar
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ZFS on Linux: Which mountpoint option when mounting manually per script?

I want to create a zpool with ZFS on Linux (7.13) on Debian Buster. The problem is that the pool will be created based on LUKS encrypted drives (not root, only external). These drives are decrypted ...
MelBourbon's user avatar
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1 answer
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ZFS pool degraded on reboot

I have a Ubuntu server set up with a 14-disk ZFS raidz2 pool. About 80% of the time, on reboot, I will end up with a degraded pool with two of the disks marked as faulted. The drives that are ...
David Chappelle's user avatar
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ZPOOL replace defective disk in exported pool

Yesterday, I put a new disk into my server. Sadly, I didn't check the disk before of failures. I added it to my pool with the command zpool add nas /dev/disk/by-id/scsi-SATA_ST31500341AS_9VS27Z4M-...
UeliDeSchwert's user avatar
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2 answers
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ZFS Reporting (on FreeBSD and Linux via ZoL)

As a longtime mdadm user is was just experiencing a disk error and remembered that I configured a Auto Mail reporting for mdadm on disk errors. Therefore i just had to insert my Mail address inside /...
Daywalker's user avatar
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zfs: flush cache without exporting

For testing I need zfs' cache to be cold. I can flush caching from the pool by removing the cache disks, exporting and importing the pool. This gives the effect I want. But would really like not to ...
Ole Tange's user avatar
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Does it make sense to create a zpool with lots of mirror vdevs?

To prefix, I am rather new to ZFS. My goal is to create an internal NAS system, with minimal chance of losing all my data. I've currently acquired four 4TB disks, and I plan to run them in a single ...
MechMK1's user avatar
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ZFS L2ARC for Mirror Pool

I was reading up on L2ARC for my ZFS. I currently have two Pools, One for Data, and the other for Linux Containers and Virtual Machines. I would like some help with L2ARC, I know how to add it but was ...
Jonny's user avatar
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btrfs Integrity and Stress Testing

A DevOps colleague is recommending that we begin transitioning our production environment to using btrfs. We have primarily ext4 filesystems, though some low-usage servers using ZFS (on Linux). As ...
Joe's user avatar
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ZFS Shares not exported until sharenfs property re-set on Ubuntu 16.04

I am setting up ZFS and NFS on Ubuntu Server 16.04LTS and have a weird issue that is causing me to go crazy. I have set up ZFS and NFS using ZFS shares as described in https://pthree.org/2012/12/31/...
Jaime R.'s user avatar
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How do I upgrade and keep my ZFS pools on Ubuntu Server?

I have a server running the 4-year-old Ubuntu 12.04 LTS with zfsonlinux installed on the machine with a 1.5TB mirrored drive setup. The Ubuntu 16.04 LTS has no upgrade path, so I'll have to reimage ...
Riking's user avatar
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Can ZFS send/receive help me recover from partial pool loss after upgrade to Ubuntu 22?

I have a long-running ZFS pool under Ubuntu, which has been through many upgrades. After upgrade from Ubuntu 20 to 22, the encrypted filesystems refuse to mount, though the rest seem OK. zpool ...
rptb1's user avatar
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Run ZFS as non-root

I'm running Debian 10 in a VM (using KVM) and I want to use ZFS as a non-root user. Here is what I did. I added this line to my sources.list file deb http://deb.debian.org/debian buster-backports ...
amrbcl's user avatar
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1 answer
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ZFS datasets no longer automatically mount on reboot after system upgrade

I have an Arch linux ZFS backup system which wasn't updated for a long time because it was working perfectly and there was no reason to bother. After a recent upgrade, though, my ZFS datasets are no ...
pgoetz's user avatar
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Growing zpool in zfsonlinux

I have 2x3TB disks with GPT and a zpool with uses a 2.7TB partition on the first disk (sda4) and 1TB on the second disk (sdb4). Reason is that initially both disks were just 1TB and I sequentially ...
divB's user avatar
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1 answer
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ZFS: good read but poor write speeds

I'm in charge of downloading and processing large amounts of financial data. Each trading day, we have to add around 100GB. To handle this amount of data, we rent a virtual server (3 cores, 12 GB ram)...
BayerSe's user avatar
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1 answer
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ZFS on Centos - "No such pool or dataset" and "devices is currently unavailable"

I'm trying to create zpools on CentOS 7 (3.10.0-327.10.1), and the zpool command seems to hate "wwn-0x" IDs. "zpool status" is clear - there are no zpools currently configured on the machine. I have ...
Locane's user avatar
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Update from zfs-0.6.2-1.el6.x86_64 to zfs-0.6.3-1.el6.x86_64 has made by zpool unreadable

After running # yum update zfs and restarting my CentOS 6 ZFS on Linux system can no longer see or interact with it's zpools. # zpool status no pools available # zpool import zpool: ../../lib/libzfs/...
84104's user avatar
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ZFS: device vdev wandered faulting zpool

I have a zpool thats now showing in a FAULTED state after a power outage rebooted the server & devices names got thrown around. I understand I messed up by adding vdevs by device name, but didnt ...
tango's user avatar
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679 views

Incorrect cache device after ZFS import

I've recently migrated from an Ubuntu machine to an Arch Linux machine. I imported the pool using the zpool import -f tank and it reported my cache drive as faulted, but my storage drives are working ...
Stephen__T's user avatar
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ZFS snapshot zd0 block device

I'm trying to make use of the ability of zfs snapshots. To explain a little how it's configured on my end: zpool create vol0 mirror /dev/sda /dev/sdb zfs create -o volblocksize=128K -V 15T vol0/...
g00gle's user avatar
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When does "zpool scrub" delete files automatically?

Background is a general discussion about ZFS and the claim that in case of permanent errors to files, it automatically deletes files unless a correct copy is available. That sounded pretty wrong to me ...
Thorsten Schöning's user avatar
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1 answer
2k views

ZFS snapshot send incremental

I have been happily using zfsnap with CentOS and ZFSonLinux in a scripted manner similar to how it is described on the web site, but have run into an issue. Unfortunately backups did not run a few ...
ak907's user avatar
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2 answers
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ZFS on Linux disk replacement best practices

I have an 8-bay NAS running Fedora 29 (kernel version 4.20.8) and zfs version 0.7.12. All of the drive bays are used for a zfs pool named “tank.” Here is the zpool layout: tank mirror-0 sda ...
user489879's user avatar
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1 answer
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ZFS test rollback doesn't work as expected

I am confused about how ZFS snapshots and rollback are supposed to work. I have a zpool containing a couple zvols (each made from partitions of a mirrorvdev). I make a snapshot like this: ~$ sudo zfs ...
Stonecraft's user avatar
4 votes
1 answer
4k views

Grow ZFS mirror

I have a ZFS pool with 6 disks in a RAID 10 configuration. I would like to upgrade the drives in one of the mirrors, from 1TB to 3TB drives. I have all the drives installed in the system. I would ...
wmantly's user avatar
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Ubuntu Xenial (16.04) "zfs share" command doesn't work for SMB shares

My problem with ZFS on Ubuntu Xenial (16.04) I've been running ZFS for years from the package maintainer's zfsonlinux.org site. Things have been good. But recently I upgraded to Ubuntu 16.04 when it ...
Ryan Babchishin's user avatar
4 votes
1 answer
982 views

ZFS - Zpool disk replace results in restarting resilver process that never ends

I replaced a broken drive with a type already used in my pool for some time. The problem I face is that the resilver process seems to be stuck in a restart-loop. Whenever I check the zpool status I ...
straumli's user avatar
4 votes
1 answer
520 views

Creating ZFS pool from liveCD with ashift=9 becomes ashift=12 when rebooted into new OS

I have created a zpool while booted on a Linux Mint liveCD (with all the ZFS packages temp apt-installed) and created a zpool with command line containing ashift=9 because my ST4000NM0033 drives (8 ...
GenerationTech's user avatar
4 votes
1 answer
2k views

ZFS on Linux: How do I correctly configure the vdev_id.conf file and trigger vdev aliasing?

I have been trying to get ZFS on Linux to read / process the vdev_id.conf file and give me a /dev/disk/by-vdev directory, to no avail. I have a SAS HBA with redundant connectivity to several hard ...
Sam Alsalem's user avatar
4 votes
1 answer
3k views

Mount ZFS dataset in unprivileged container

First a bit of information about my configuration: Ubuntu 15.10 ZFS pool created LXC containers stored in pool/lxc Dataset created in pool/mydataset owned by user1 Now I need one of the containers ...
ghetto's user avatar
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4 votes
2 answers
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Why does zfs fail to cache this workload when "normal" filesystems cache it completely?

Update: because recordsize defaults to 128k, the amount of data read by the test program is much larger than the ARC on an 8GB system and still slightly larger than the ARC on a 16GB system. Reducing ...
aranc23's user avatar
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4 votes
2 answers
848 views

Create a backup of a ZFS volume

I am unable to create a replica of an existing ZFS volume and snapshots. For my other volumes, I am synchronizing the backups nightly via zfs send / zfs receive and that works okay. That said, I ...
Walter's user avatar
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4 votes
0 answers
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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 ...
Saurabh Nanda's user avatar
4 votes
0 answers
310 views

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 ...
Ketan's user avatar
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4 votes
0 answers
1k views

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 ...
coverflower's user avatar
4 votes
0 answers
796 views

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 ...
Apollo13's user avatar
4 votes
0 answers
3k views

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 ...
Pascal's user avatar
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1 answer
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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 ...
Chris Tonkinson's user avatar
3 votes
2 answers
2k views

How can I passively examine the contents of a ZFS send stream?

I have some stored ZFS "send streams" (i.e., they were created by redirecting the output of zfs send to a file). I would like to examine the contents of these streams without receiving and writing ...
ruief's user avatar
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3 votes
2 answers
603 views

ZFS: Handling massive no. of concurrent RW operations and failover

I have a single ZFS/Linux instance with a file that can grow to those crazy sizes supported by ZFS. A large number of concurrent users need to read/write from/to this file over the public inter net. ...
Harry's user avatar
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3 votes
2 answers
1k views

Use QLC SSDs as RAIDZ (scientific archive)?

We are building a system for the archival and scientific analysis of some weather data. The setup is redundant, with two HP DL580, Proxmox (ZoL) and some GPUs for analysis. On each server we plan 5 ...
Benoit's user avatar
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3 votes
2 answers
2k views

Is ZFS L2ARC required if primary data is already on SSD?

I'm trying to tune ZFS on Linux for my workload (Postgres and a fileserver on the same physical machine [1]), and wanted to understand if I really need L2ARC, or not. If the information given at ...
Saurabh Nanda's user avatar
3 votes
2 answers
7k views

Using exotic setups to maximize capacity (when using different sized disks) in ZFS raidz

I have 2 x 4TB disks and 3 x 6TB disk which I want use with ZFS. My objective is to maximise the usable storage space whilst allowing for a single disk failure. Ideally a raidz setup would be used ...
Greg's user avatar
  • 1,677
3 votes
2 answers
4k views

Increase space of ZFS pool over iSCSI SAN, online

I have an iSCSI volume of 96GB on SAN, which has ZFS pool implemented on it. i have resized the size of SAN volume from 96 to 120GB, but the zpool list only shows the old space (96GB). how to achieve ...
Farhan's user avatar
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3 votes
1 answer
2k views

Are ZFS snapshots really "free"?

I've heard many times that ZFS snapshots are "free", that because of ZFS' copy-on-write design snapshots do not consume any disk space unless data is changed, and only then the space usage ...
Josh's user avatar
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3 votes
2 answers
6k views

Inplace migrating ZFS RAIDZ with 3 drives to 4 disks, when pool has more than 1/3 of free space

On creating my RAID-Z pool on ZoL I assumed, I could easily just drop-in additional disks later on. Meanwhile I learned that this is yet not possible. But... I had a similar problem on creating my ...
bentolor's user avatar
  • 141
3 votes
1 answer
7k views

ZFS Send and ZFS receive dataset without -RI incremental replication sync

Is there a way I can send ONLY the latest snapshots to the backup zfs system even though it has previous snapshots? When I try I keep getting error: "cannot receive new filesystem stream: ...
htfree's user avatar
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3 votes
2 answers
5k views

Limiting ARC Size for the proposed system

I have a pool of 5 x enterprise 12Gps SSD that I use for internal storage for a proxmox server. This pool is used to stand up VMs and containers. The problem is that it is eating up a lot of my ...
Shery's user avatar
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