Stack Exchange Network

Stack Exchange network consists of 175 Q&A communities including Stack Overflow, the largest, most trusted online community for developers to learn, share their knowledge, and build their careers.

Visit Stack Exchange

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.

2
votes
1answer
30 views

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 ...
1
vote
1answer
31 views

How to mount a ZFS dataset with given uid/gid?

I feel like I am missing something very simple / basic here, but I wasn't able to figure out how to mount a ZFS dataset such that the mount point (root directory) has a given uid/gid ownership? ...
5
votes
1answer
1k views

ZFS Heavy Write Amplification due to Free Space Fragmentation

I have setup ZFS RAID0 for PostgreSQL database. The Storage and Instances are in AWS EC2 and EBS volumes. NAME SIZE ALLOC FREE EXPANDSZ FRAG CAP DEDUP HEALTH ALTROOT pgpool 479G ...
2
votes
1answer
26 views

How to resume a “zfs receive” on Debian/stretch?

How do I resume an interrupted ZFS send/receive on Debian/stretch via ZFS on Linux? It seems that the zfs send -t option isn't there.
3
votes
2answers
106 views

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 ...
1
vote
1answer
36 views

How to monitor data transfer speed and volume between two computers on same network

My application on Win2012 Server stores its cache on a ZFS appliance in the local network, during peak load we are seeing some performance degradation, this only happens in the production environment ...
0
votes
1answer
35 views

How to remove faulted disk from ZFS pool once spare replacement done

I have a ZFS pool in the current state: [root@zfs01 ~]# zpool status pool: zdata state: DEGRADED status: One or more devices could not be used because the label is missing or invalid. ...
2
votes
0answers
32 views

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 ...
1
vote
1answer
42 views

Lack of TRIM support — will benchmarks get progressively slower on ZFS + SSD?

Context: I'm on a Toshiba 512 GB NVMe (Model: KXG50ZNV512G) I'm seeing this weird behaviour while benchmarking Postgres on ZFS-on-Linux (via pgbench), where the second and third runs of a benchmark ...
3
votes
2answers
276 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 ...
2
votes
0answers
43 views

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 ...
0
votes
0answers
9 views

ZFS stangre thing with unavaible pool

I have an old debian with ZFS 0.6.3 ( as far as I remember ) under the installed OS half of my pool is in "UNAVAILABLE" state. I try to explore more with FreeBSD live CD and Debian ZFS rescue disc ...
1
vote
1answer
57 views

Formatting/creating file system on multipath volume for ZFS on Linux?

I inherited a ZFS on Linux (CentOS) storage pool and I have a faulty multipath device (mpathah) in my pool: raidz3-6 DEGRADED 0 0 0 ... ... mpathba ONLINE ...
1
vote
1answer
158 views

ZFS not installed into upgraded kernel (4.19)

I want to use the latest kernel (currently 4.19) with Ubuntu Server 18.04, and I also want to use ZFS. Although ZFS appears to install correctly, it apparently does not get installed into the right ...
3
votes
1answer
1k views

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 ...
2
votes
0answers
100 views

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 ...
5
votes
2answers
259 views

At my wits end. What could cause my server to randomly hard reset? (Seems to be related to ZFS)

I have a server that I built years ago that has worked like a champ. But within the past few months it has started to become seriously unstable with no discernible pattern. I have been debugging it ...
17
votes
4answers
1k views

If a RAID5 system experiences a URE during rebuild, is all the data lost?

I understand the argument regarding larger drives' increased likelihood of experiencing a URE during a rebuild, however I'm not sure what the actual implications are for this. This answer says that ...
3
votes
0answers
66 views

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: ...
4
votes
1answer
136 views

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 ...
2
votes
2answers
195 views

ZFS on linux - L2ARC not being read

Today I did some tests on L2ARC using the latest ZFS on Linux 0.7.10. I have seen that the L2ARC gets filled with data, but with the default module settings the data that is residing in L2ARC cache is ...
1
vote
1answer
451 views

ZFS (on Linux): zfs import cannot import online pool

I have a pool that cannot be imported even though it is detected and is online. $ zpool import -d /dev/disk/by-id pool: threetb id: 10173957064206389394 state: ONLINE action: The pool can be ...
1
vote
1answer
221 views

ZFS on Linux: clear receive_resume_token pointing to a no longer existing snapshot

I am using syncoid from sanoid project to create copies of ZFS filesystems on a different machine in my test environment (a couple of Raspberry Pi) I messed up with a snapshot on origin machine: one ...
4
votes
1answer
836 views

Wait before zpool import on Ubuntu boot

I have installed Ubuntu 18.04 on a Dell PowerEdge R720xd using ZFS. There are two 1TB boot drives in a ZFS mirror configuration. I followed the instructions in the ZFS on Linux Wiki. (Note: My system ...
3
votes
1answer
1k views

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 ...
0
votes
1answer
110 views

Import failing with ZFS pool that has both disks and files

I recently ran out of space on my ZFS pool, and since I needed a quick solution for more space and didn't plan to use the pool for much longer, I just added a file as a new device (vdev?) to my pool ...
0
votes
1answer
167 views

Why does /dev/disk/by-id directory have cdrom device only and which one of /dev/disk/by-X is recommended for creating zfs pools?

Im running a ubuntu 16.04 machine in esxi enviroment, i am going through zfs on linux faq and it recommends to use /dev/disk/by-id for home servers due to inconsistent nature of /dev/sdX names but ...
0
votes
0answers
88 views

Reading iostat utilization with ZFS zvols

I am having a hard time understanding the output of iostat -x with specific regards to ZFS zvols. I'm running Proxmox 4.4, fully updated and encountering some generally poor IO performance. While ...
4
votes
1answer
373 views

Docker service starts before ZFS

I am using Docker CE on Ubuntu 16.04, with ZFS as storage for Docker. Setup is pretty much standard: There's a zpool that has multiple disks On the zpool, there's a zfs filesystem with mountpoint /...
0
votes
0answers
127 views

Package dependency issue, not sure safest way to proceed

I am running into a package dependency issue. Can someone help make sense of how to resolve this? Q What steps do i need to take when it says Requires: zfs-kmod = 0.7.7 Available: kmod-...
2
votes
2answers
525 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 ...
1
vote
2answers
548 views

How to attach a 2-device striped mirror to a pool?

I have a single-drive pool consisting of a 2TB HDD. I have two 1TB drives I can use in mirror - I'd like to add redundancy to my pool. How can I attach these two drives as a single device so that ...
1
vote
1answer
460 views

1 SSD + 1 HDD - how should I design my ZFS storage?

I have a PC with a 256 GB M.2 SSD drive used for Linux Mint root, swap and home partitions right now. I have a 2TB HDD for all my data (I keep that separate from home dir actually, because users' home ...
2
votes
1answer
174 views

3TB + 4TB HDD - should I deploy ZFS?

I have a production machine at work that was running on a single 3TB HDD. Now I've added another 4TB drive into it. The 3TB drive has been used for 1,5 years at this point, the 4TB is brand new. I ...
0
votes
0answers
47 views

How to delete the pool with state = Faulted?

I have a pool named test_pool and i can only see it when "zfs import" is run. How can i delete this pool and detach associated device from it ? # zpool import pool: test_pool id: ...
2
votes
1answer
499 views

ZFS logicalreferenced vs referenced

After sending a zvol from one pool to another I was alarmed to find that only half the data was "there" (according to REFER). Then I noticed on the sent snapshot that referenced is 302G and ...
1
vote
1answer
909 views

Can I remove a disk from a zpool raidz2?

Unfortunately I do not really understand zfs. I have a Proxmox 5 node with 5 300GB disk in raidz2. History: zpool create -f -o cachefile=none -o ashift=12 rpool raidz2 /dev/sda2 /dev/sdb2 /dev/sdc2 /...
0
votes
1answer
87 views

Cannot format a drive once used in a ZFS pool

I have created a ZFS test pool with a drive - now I have pulled thet drive out and want to format it to EXT4 and use it outside of ZFS. I think the pool wasn't properly destroyed. Now when I plug the ...
2
votes
1answer
86 views

In my ZFS box, why is my cache devices leaving a bunch of free space?

I have a ZFS system serving many VMs. In it, we installed 12x4TB SAS disks and configured them in a mirror. We added two PCI-E SSDs (Samsung 960s with 512GB each), but they are each consumed to just ...
4
votes
1answer
440 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 ...
0
votes
0answers
38 views

Install Linux on USB pendrive for new servers

I wonder if installing (and running) Linux (CentOS, in this case) from a USB pendrive is a smart or stupid move. Please note that: I am talking about server environment, not clients; I mean full OS ...
2
votes
2answers
301 views

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/...
1
vote
1answer
30 views

Not able to find zfs pool source directories

I am not able to understand where zpool directories are kept on my machine? zfs list shows this output NAME USED AVAIL ...
6
votes
1answer
837 views

How can I remove dedup from my pool without running out of RAM?

I have a server with 8 disk bays filled with 3 TB disks. Using 4 mirrored vdevs of 2 disks each, this gives me 12 TB of redundant storage. Here's the issue - I read somewhere that I needed "x GBs of ...
3
votes
1answer
1k views

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 ...
0
votes
0answers
142 views

ZFS write performance with SAS expander

I have a ZFS storage server running Ubuntu 16.04. I recently added a 12G SAS expander with 6 Seagate ST8000NM0055's. When I create a pool of mirrored vdevs and try to sync data from another array in ...
4
votes
0answers
75 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 ...
1
vote
1answer
45 views

How to get zfs to use a higher portion of the cache device? (Currently using 5GB / 480GB)

I am running a 4 disk raid 10 setup with a fast 480GB SSD. When looking at iostat -v the cache device has only 5GB of allocated space and the rest is free. Both primarycache and secondarycache are ...
3
votes
0answers
239 views

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 ...
2
votes
0answers
266 views

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 ...