Questions tagged [zfs]
ZFS is a combined file system and logical volume manager designed by Sun Microsystems The features of ZFS include protection against data corruption, support for high storage capacities, efficient data compression, integration of the concepts of filesystem and volume management, snapshots and copy-on-write clones, continuous integrity checking and automatic repair, RAID-Z and native NFSv4 ACLs.. -Wikipedia
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Why does ZFS scrub not complete?
First off let's start with what I'm running. This is a home media server running Ubuntu 16.10. I have one pool of mirrored 6 terabyte drives that are about half full. I built the system about a month ...
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Why does ZFS rollback destroy intermediate snapshots?
Having used btrfs before, I was surprised to find out that rolling back a snapshot in ZFS not only changes the “working set” of files, but also requires that any snapshots which are newer than the ...
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Btrfs/ZFS Network Replication
Is it possible to replicate a ZFS or Btrfs raid volume in real-time (or as close to as possible, network specs aside) over a network?
ZFF and Btrfs are ideal because of their CoW properties.
I'm ...
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How ZFS deals with bad sectors?
I have a disk with a couple of bad sectors. I've used badblocks to check which sectors were faulty. dd could not write zeroes to them and smartctl -t long /dev/sdx has failed.
I know that you can ...
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What are data integrity / bit-rot protection options on CentOS 7?
I have a 2 disk CentOS 7 machine build that I need data integrity / bitrot protection on. How can I achieve this?
Note from my reading btrfs,zfs and DM-Integrity does not seem to be options.
Btrfs ...
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5
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How can I detect whether an "NMI watchdog: BUG: soft lockup" is a hardware or a software issue?
Soft Lockup
dmesg reports in my laptop, since quite some time now, NMI watchdog: BUG: soft lockup every time I try to use updatedb or firefox. Samples of what is reported posted at https://github.com/...
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4
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zfs on linux device names
I'm a native Solaris guy and as I look into more Linux use, I'm a little confused about a theme I'm seeing in some posts about ZFS on linux.
The posts refer to the use of device names when defining a ...
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4
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ZFS (on Linux) swap error upon shutdown
I have installed Debian stretch on ZFS (including the root filesystem) and have made a volume on the root pool which I am using as swap. Everything is working fine, except that I am seeing the ...
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Merge partitions
Due to some unfortunate partitioning I ended up with the following layout:
/dev/sda1 (0-120MB) 128MB (boot)
/dev/sda2 (128MB-500GB) 500GB (empty)
/dev/sda3 (500GB-1TB) 500GB (zfs)
/dev/...
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0
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What's the sharenfs syntax for using a netgroup with ZFS on Linux?
I'm trying to set up an NFS share with a new ZFS dataset (pool/data) and trying to share using an existing netgroup (foogroup). Running Ubuntu 20.04 on both the NFS server side and client side, it ...
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3
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1
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ZFS ARC dnode size > dnode max size
I've copied a reddit post which asks my question and haven't been answered:
I've been tinkering with a tool to monitor ZFS usage and statistics for the last few weeks. It's encouraged me to learn a ...
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3
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0
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lsblk showing "P" as disk capacity which is wrong
As mentioned in the title, lsblk has "P" in couple of my disk when clearly I don't have any disk that has petabyte of capacity.
Or could the "P" here mean something completely ...
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3
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Backup entire zfs pool to different filesystem
I have a zpool with around 6TB of data on it (including snapshots for the child datasets). For the important data in it, I already have backups on filesystem level. As I need to perform some rather &...
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3
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Forcing the failover to a hot spare in a degraded ZFS pool
I have a simple 5x1TB RAIDz1 configuration (tank? pool? vdev?), with a global spare assigned to it. One of the 5 drives in the array is listed in a FAULTED state (corrupted data), and the spare is ...
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ZFS: Is scrub safe to stop, if zpool seems to have both resilver and scrub happening concurrently after disk reinsertion?
I have an Ubuntu 20.04 server which is running ZFS with a 56TB disk array.
We have a disk marked as FAULTED. While trying to deal with this, we accidentally pulled out the wrong disk, but put it back ...
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Extremely poor performance for ZFS 4k randwrite on NVMe compared to XFS?
I've been a fan of ZFS for a long time and I use it on my home NAS, but in testing its viability for production workloads I've found that its performance is inconceivably bad compared with XFS on the ...
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Does anyone know the way to undelete file on ZFS?
Is there any way to undelete file on ZFS.
I overwrote JPG file with the scanned image.
Unfortunately, I didn't take snapshot.
But ZFS uses the CoW mechanism, overwritten data may still alive, I think.
...
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3
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0
answers
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FreeBSD 11.2: how to resize the boot options menu on a UEFI/GPT/ZFS machine?
Is there a way to resize the boot options menu in Freebsd 11.2 on a UEFI/GPT/ZFS machine (zfs-on-root)?
On multiple machines, the installation resulted in the boot options menu being rendered in a ...
user223600
3
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1
answer
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How to force OmniOS (illumos) "format" properly recognize disk geometry?
I have a FreeBSD-initialised 8-disk vdev, all 10TB WD RED, now on a server with OmniOS r151026, connected via LSI 3008 HBA.
At POST, the card shows all disks with right geometry (I can post picture ...
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zfs pool not available on boot after setting noatime and drive idle times with hd-idle / hdparm
At first, I set up my RHEL7-x64 to sleep the zfs drives using this,this, and this. I believe I tried hd-idle first, when the problems began.
I had written a script idle_drives_enable to handle ...
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Incremental backups - rsync with hard links, or rsync to zfs with snapshots?
I need to set up a backup server to pull data from on-site linux servers. The server will be running Ubuntu 16.04.
A requirement is to be able to access backups of files which have been subsequently ...
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Does ZFS reads and writes show up in vmstat -p output
I am aware of ZFS not using the regular file system cache for caching pages for reads or writes (ZFS uses ARC and ZILs).
My question is would "vmstat -p" on a recent Solaris machine also reflect read ...
3
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0
answers
175
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Wrong service startup order when not booting into single-user mode
I'm asking about a Debian Wheezy system running sysvinit and ZFS on Linux. While my problem manifests itself with ZFS, I strongly suspect that the underlying problem is not ZFS-specific.
For some ...
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3
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0
answers
505
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Account for missing space as reported by ZFS list
This is a question regarding the available space as reported by zfs list that does not meet user expectations. I have looked at similar questions, but I still don't understand the zfs list output. Let ...
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3
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1
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Why can't I import an ZFS pool without partitioning the data disk with fdisk?
I have a strange situation here, in which I am unable to import an ZFS pool that I brought from another OS UNLESS I fdisk the disk of the pool. I am puzzled as to why this is happening and hoping to ...
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1
answer
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How to Remove a Large File from ZFS Snapshots and Reclaim Space?
I have a series of daily ZFS 100Mb snapshots of archive_zp/my_zfs, going back 100 days. At day 60 (between @ss59%ss60) I had added a 10 GiB sized archive_zp/my_zfs/BIG.iso file, that 10 GiB now ...
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2
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zpool import error
I suffered a complete pool failure – the fan in the array chassis stopped working and all drives overheated. After cooling down, all drives checked out ok using seagate's seatools test utility and ...
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0
answers
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Samba does not show all ZFS snapshots
I am setting up a file server that uses Samba together with ZFS.
I have configured Samba such that it shows the ZFS snapshots under "Previous Versions" in Windows; following is an excerpt of ...
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2
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0
answers
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How would I find the increase in Free Space if I delete a tree on ZFS?
Consider a ZFS Pool with deduplication enabled. Now consider multiple directory trees that contain identical content [D1 thru D10]. The first [D1] takes up TB of "real" disk space. The ...
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2
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zfs scrubbing not detecting corruption in backing store - why?
A bit of background:
I am storing VM images, my home directory, my mail, my media collection on single-primary DRBD devices built on LVM logical volumes built on two RAID0 arrays (one in each DRBD ...
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2
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Ubuntu 21.04: ZFS pool automount not working
setup: Ubuntu 21.04 (with latest updates). The problem happened even before 21.10 was out. I just never bothered fixing it until now.
zfs version is:
root@myserver:~# zfs --version
zfs-2.0.2-1ubuntu5....
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Linux kernel with ZFS eating my ram (2x of arc_max)
First up, It seems my kernel is using way too much ram
$ grep Slab /proc/meminfo
Slab: 21794184 kB
See all of /proc/meminfo
and /proc/slabinfo
$ free -h
total used ...
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0
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ZFS mirror bootable? (to boot from it in case the other fails)
I'm looking to have a ZFS mirror on my small fileserver, that's essentially one "mobile workstation" with two 2.5" drive bays, DVD drive, USB3, all the slots, and ports you can imagine, ...
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0
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Warm up ZFS cache - force file into l2arc
Currently I use:
while true; do
cat file >/dev/null
echo 3 | sudo tee /proc/sys/vm/drop_caches
done
to warm up ZFS's l2arc. When I can see accesses are primarily coming from the cache disk, ...
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2
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0
answers
495
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How to remove an errant ZFS spare entry?
I have a ZFS spare reporting in an odd way. There is no sda spare. The spare "was" actually in use, listed as spare3 in screenshot below. However, sda is in fact the non-ZFS boot drive.
...
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2
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dedup seems to be working, but free space says otherwise
I'm testing out dedup with zol on Debian.
I've set dedup=on on the zvol before copying any data, then copied data to the mounted volume with no problems.
Then I've run cp -r folder1/* folder2/ on test ...
2
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0
answers
70
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Mount order problem with systemd
Running Raspbian Buster. I have a loopback mount defined in fstab (bind option) where directory A is looped in as B.
I have another service started later (with systemd After=local-fs.target) that ...
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1
answer
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How can I change a ZFS mountpoint from legacy to be handled by ZFS
Currently using ZFS on ArchLinux. I have two datasets that I originally setup with legacy mountpoints:
# zfs get mountpoint tank/data/home
NAME PROPERTY VALUE SOURCE
tank/data/...
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2
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0
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Confused about using `setuid` on a FreeBSD mounted dataset to ensure all files/dirs have a fixed owner?
Initially I thought that what I'm trying to do was simple. But the more I look at FreeBSD man pages, the more confused I'm getting about whether it's even possible.
I have a zfs pool that is used for ...
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Home NAS: Best setup to ease data recovery in case of hardware failure? Should I get rid of HW raid 1?
I'm not quite sure how to formulate the question here. I built myself a low energy NAS with an Intel N4200 with 8GB RAM. For the hard drives I'm using two WD red in a Raidon GR3660-B3 which is running ...
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2
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1
answer
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How to keep linux pagecache minimal?
I want to setup Debian system with ZFS as primary filesystem and some as secondary (ntfs, ext2/4). When I'll read/write from non-ZFS filesystems pagecache will grow and will force zfs arc to shrink. I ...
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523
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Zfs Replace - How to remove drives after replaced
I have a zfs Z2 (Raid 6 equivalent array) comprising 8 1Tb drives, that previously had been working well for a couple of years.
Due to disk problems, I have had to replace at first one drive, then ...
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2
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0
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Mount ZFS Pool as Internal Drive
I'm running Debian Jesse with Gnome 3. I've created a ZFS pool named Data and set its mount point to /media/[user]/Data. Below is a screenshot of my /media/[user] folder and the desktop showing how ...
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1
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setting a quota on zfs doesn't work
I'm on FreeBSD 11. In order to set quota on my pool named storage, I enter these configs in terminal:
zfs set quota=10G storage
zfs set userquota@user1=1M storage
The problem is when I connect from ...
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2
votes
1
answer
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ZFS groupused value not current
On my Solaris 11 box I have a zfs pool (z) that uses 100G group quotas on each user in /org/users folder. One user had reached their quota and cleaned up their data. The df output, that had previously ...
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ZFS (on linux) performance issues
I have a server setup with RaidZ2 (8 disks in array) + 2 spares (+ system disk). The disks are 6TB each, 7200 RPM SAS
The machine runs Centos7 x86_64 (not a VM), and has 128 GB of RAM and 48 cores (...
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2
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0
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424
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ZFS allocation algorithm
I'm looking for a way to know which algorithm ZFS is using to find free blocks.
By default there are two algorithms:
Best Fit
First Fit
These are automatically changed once a threshold is passed ...
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2
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0
answers
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How to import ZFS pool with different configuration
After rebooting my ZFS pool was unable to open my main pool. The exact error that I'm getting is: "The pool metadata is corrupted and the pool cannot be opened"
When I checked the zpool configuration ...
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1
vote
1
answer
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Storing large amount of small files in HDD pool
I have a Z6 HDD pool with 6 x 18T drives and a SLOG, LZ4 compression is enabled by default. Now I need to store large amount of small files and I'm worried about fragmentation.
The files:
70K files ...
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1
vote
1
answer
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Installing pot on FreeBSD: no such pool 'zroot'
According to the documentation of pot, the following has to be done to install it:
pkg install -y pot
pot init -v
I tried this, but ended up with the following error:
cannot create 'zroot/pot': no ...
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