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 ...

learn more… | top users | synonyms

15
votes
5answers
16k views

How to delete all but last [n] ZFS snapshots?

I'm currently snapshotting my ZFS-based NAS nightly and weekly, a process that has saved my ass a few times. However, while the creation of the snapshot is automatic (from cron), the deletion of old ...
3
votes
1answer
93 views

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)...
43
votes
12answers
36k views

ZFS vs XFS

We're considering building a ~16TB storage server. At the moment, we're considering both ZFS and XFS as filesystem. What are the advantages, disadvantages? What do we have to look for? Is there a ...
2
votes
1answer
36 views

Adding more mirrored vdevs to a ZFS pool on Ubuntu

I'm on Ubuntu 16.04.1 LTS and I have a ZFS pool named unas containing two mirrored drives. I have now attached two more drives and I want to add these new drives to my unas pool as a pair of mirrored ...
0
votes
1answer
41 views

ZFS: ARC and buffer cache with PostgreSQL

I am using Ubuntu Xenial, zfs and PostgreSQL 9.5 with all updates available atm. All testing is done on EC2 m4.xlarge (8GB RAM) and table size ~4GB. PostgreSQL effective_cache_size=6GB. First ...
3
votes
1answer
1k views

Linux ZFS does not buffer writes to write buffer (SLOG/ZIL)?

When experiencing write I/O, the log column in zpool iostat -v does not show any ZIL activity, ever. This results in higher than expected wait times when writing data to disk (sometimes over 80ms ...
4
votes
2answers
125 views

ZFS checksum errors, when do I replace the drive?

I'm fairly new to ZFS and I have a simple mirrored storage pool setup with 8 drives. After a few weeks of running, one drive seemed to generate a lot of errors, so I replaced it. A few more weeks go ...
4
votes
2answers
45 views

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 ...
15
votes
7answers
3k views

recommendations for efficient offsite remote backup solution of vm's

I am looking for recommendations for backing up my current 6 vm's(and soon to grow to up to 20). Currently I am running a two node proxmox cluster(which is a debian base using kvm for virtualization ...
2
votes
1answer
2k views

Error creating new slice using gpart on FreeBSD

The virtual hard disk of one of my VPS has been enlarged, and I want to create a new ZFS slice using the extra space, but I couldn't be able to perform that. # gpart add -s 10G -t freebsd-zfs da0 ...
26
votes
7answers
16k views

Is bit rot on hard drives a real problem? What can be done about it?

A friend is talking with me about the problem of bit rot - bits on drives randomly flipping, corrupting data. Incredibly rare, but with enough time it could be a problem, and it's impossible to detect....
3
votes
1answer
1k views

ZFS, NFS and Nexenta

Is this message familiar to someone ? zfs-clu-01a rpcmod: [ID 851375 kern.warning] WARNING: svc_cots_kdup no slots free zfs-clu-01a last message repeated 75220 times We have a lot of trouble ...
2
votes
2answers
24 views

Delete ZFS filesystem with snapshots but no other children?

You can delete a ZFS filesystem (or other dataset) with zfs destroy <dataset>. That fails if the dataset has children, including snapshots. zfs destroy -r <dataset> will remove the ...
5
votes
2answers
5k views

zpool import: volume FAULTED with corrupted data, is it possible to save some data?

I was using Freenas 8.2 and decided to upgrade to 9.2. All seem to go well, upgraded zfs to 28 and rebooted. During next boot it seem to take forever and at some point I decided to turn off the ...
1
vote
0answers
29 views

ZFS restarts resilvering over and over again. Also very slow

Here's one of my Solaris 10 servers after a couple of disk replacements in a zpool pool: volume state: ONLINE status: One or more devices is currently being resilvered. The pool will ...
1
vote
1answer
1k views

No more space on FreeNAS 9.3. But only half of space actually in use based on “du -sh” command

This morning I got a warning on my FreeNAS 9.3 machine about "Not enough space" warning: The capacity for the volume 'SeanVolume' is currently at 85%, while the recommended value is below 80%. It's ...
0
votes
2answers
1k views

FreeBSD 10: NFS unable to export folder

I am unable to export a folder using NFS. /etc/exports /storage/test -maproot=nobody client /storage/test1 -ro -maproot=nobody client /storage/test2 -ro -maproot=nobody client The first folder ...
4
votes
2answers
190 views

Priming a ZFS L2ARC cache on Solaris 11.3

Is there a good way to prime a ZFS L2ARC cache on Solaris 11.3? The L2ARC is designed to ignore blocks that have been read sequentially from a file. This makes sense for ongoing operation but makes ...
2
votes
0answers
44 views

ZFS on linux with centos 7.2 sync reads slow to crawl when executing sync writes

We are running ZFS on linux with centos 7.2. The array has 26 6tb Seagate sas drives in a mirrored configuration and then stripped across the mirrors to form our pool. 128gb arc, 480GB l2arc PCI ...
2
votes
1answer
34 views

zfs mountpoint not using the dataset

I am currently building a media server based on Linux Mint. The OS is installed on a small SSD and the intention is to store the media files on two HDDs (2TB + 4TB). To this end I have created a zfs ...
1
vote
1answer
83 views

Ubuntu 16.04 LTS with ZFS hanging on boot

Ubuntu 16.04 LTS host won't come back up after maintenance reboot. Seems to hang when it tries to bring up ZFS. Last message in the console is: Starting import ZFS pools by cache file... VERIFY(rs ==...
3
votes
2answers
2k views

Should I create ZFS zpools with whole disks or partitions?

I am making zpools on FreeBSD machine. While creating zpools I observe these two cases: If I take raw disks and create zpool then I am able to form zpools and they are working perfectly. If I format ...
0
votes
0answers
18 views

Best topology for mirrored data servers in GlusterFS

I am currently laying out the topology for a GlusterFS cluster, which is expected to grow pretty fast. Therefore, scalability and resiliency are key in this regard. The topology I've come up with is ...
0
votes
0answers
28 views

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 ...
1
vote
0answers
52 views

How to enable space reclamation from KVM guest to ZFS zvol iSCSI target?

I have a ZFS volume "tank/kvm/webhosting", exposed through iSCSI (using tgt) to KVM guest. <disk type='block' device='disk'> <driver name='qemu' type='raw' cache='none' io='native' ...
2
votes
2answers
2k views

ZFS - Recover or repair a corrupted file in a snapshot from backup?

A pool has suffered permanent data corruption to file data that's part of a snapshot. If the file data was part of the filesystem (and not part of any snapshot), I could simply recover the file from a ...
2
votes
2answers
89 views

How do I configure Ubuntu 16.04 to show my ZFS zvols internal partitions?

I seem to be missing some zvol functionality, but I'm not sure how to phrase it. I had this functionality with these same zpools on an ArchLinux installation. (Migrated the server.) Ubuntu puts the ...
1
vote
0answers
27 views

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 ...
2
votes
1answer
60 views

Recover ZFS deleted file names [closed]

I have to work on server with ZFS file system to recover deleted file names or recover actual files. I have very basic knowledge about ZFS and couldn't find easy way to achieve this. I just wonder if ...
0
votes
0answers
112 views

Solaris 10 Update 8, ZFS boot/root zpool and moving disks around

One of my OLD machines is running solaris 10 Update 8 (x86). It has a mirrored ZFS I use for "root zpool". Both disks are failing so I plugged a new disk in a USB port and attached the new disk to ...
2
votes
2answers
50 views

Will ZFS automatically switch to fault tolerant when I add a third drive?

If I start off with a 2 drive stripped ZFS POOL will it automatically become a fault tolerant POOLS like RAID-5 when I add the third drive? I can't seem to find anything in the ZFS CheatSheets I find ...
1
vote
1answer
188 views

zpool showing more storage than it should

I just expanded my zpool named storage with 3 HGST 6TB drives in raidz1. I thought this would add only about 11.x TB of storage (since they are really 6000GB drives) how ever now zpool list shows I ...
2
votes
1answer
53 views

ZFS - Solaris 10 doesn't see disks after reboot on HP Pro DL380 G7

The current box has 2 logical drives, shown in P410i Array Controller (F8 during POST) as: Logical Drive 1 - 2 SAS 72GB HD Raid10 <----root pool disk Logical Drive 2 - 4 SAS 146GB HD Raid 5 <-...
2
votes
2answers
91 views

JBOD server for ZFS without dedicated boot drive

I am looking at buying a cost-effective machine for using openAttic, which is simply Ubuntu 14.04 64bit with ZFS. The server I am looking at gives me 8 bays of 3.5", where I plan to put SAS 7.2k ...
0
votes
0answers
25 views

ZFS Snapshot showing unreachable inside snapdir

I am using ZFS with Linux 3.19.0-58-generic. I have created some snapshots, but when I cd into these directories after one point it becomes unreachable, what does that mean ? Is there any workaround ...
5
votes
1answer
75 views

Is the size reported by `zfs send` exact or estimated?

Consider the following command and the output: zfs send -Pvi \ tank/vms/langara@zfsnap-2016-05-11_00.00.00--1w \ tank/vms/langara@zfsnap-2016-05-13_00.00.00--1w \ | dd > /dev/null ...
2
votes
2answers
363 views

rsnapshot vs zfs / btrfs snapshots

Currently I'm using rsnapshot to implement a daily / weekly / monthly backup scheme on an external disk. Lately I've been reading alot about copy-on-write file systems like zfs and btrfs. I quite like ...
2
votes
1answer
74 views

is it possible to convert dataset to sparse volume (thin provisioning)?

I've created ZFS datasets and installed virtual servers into them. Suddenly my ZFS volume free space is gone, but not all space is used in each dataset. I want to introduce thin provisioning (use ZFS ...
0
votes
0answers
42 views

ZFS mirror migrated to other system with dd -> zpool import fails

I'm pretty new to ZFS and this might be an easy problem (but I don't find any discussions about how to do this): I've messed up a FreeBSD installation on a Root-on-ZFS mirrored ZFS Pool on a ...
1
vote
1answer
53 views

ZFS Send Script works when run manually but not in Cron (Already tried common solutions)

Script on sending end is as follows: #!/bin/sh #Variables bigdata=vid-zfs-live/bigdata today=`gdate +%m-%d-%y` yesterday=`gdate -d'yesterday' +%m-%d-%y` #Actions zfs snapshot -r "$bigdata"@"$...
5
votes
4answers
3k views

MongoDB and ZFS bad performance: disk always busy with reads while doing only writes

I have huge performance issues using MongoDB (i believe it is mmapped DB) with ZFSonlinux. Our Mongodb is almost only writes. On replicas without ZFS, disk is completely busy for ~5s spikes, when app ...
0
votes
2answers
35 views

Can the type of a previously created ZFS pool be changed?

I have a 2-drive zfs pool created in mirror mode. Now I've managed to get my hands on a third drive, and I was wondering if I could add the drive, and change the pool type to raidz, which is pretty ...
1
vote
1answer
170 views

Can ZFS snapshots on a NAS (accessed via Windows Previous Versions) be made more flexible in regard to renaming files?

I have a NAS running on OpenSolaris/illumos/OmniOS with several shared ZFS file systems where autosnaps are active to preserve a history (keep 4 15-minute snaps, 24 hourly snaps, 7 daily snaps and so ...
1
vote
0answers
21 views

Does zfs send scrub the sent data?

To my knowledge ZFS as a filesystem checks for data errors during each access to the data. I would therefore assume that it actually performs something like a scrub before sending the data thereby ...
1
vote
1answer
264 views

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 ...
1
vote
1answer
47 views

zfs for Hadoop cloud instead of ext4 [closed]

Right now I have couple of linodes with ext4. I have a hadoop setup. What benefit would I get if I migrate my file system from ext4 to zfs. Will there be any benefit in response times? Any speed ...
3
votes
2answers
108 views

ZFS scrub load average is ridiculously high

I have a relatively new box here running Ubuntu with ZFS-on-Linux across an 18-disk array. The first couple of times I did a zpool scrub, it seemed like everything worked nicely, but the last several ...
1
vote
1answer
43 views

How to avoid loosing changes on the root filesystem when kernel upgrading?

On Solaris and variants, it makes a zfs clone of the current / filesystem and installs the new kernel there. When rebooting you get the new /. In my case I have a /scripts directory, so if I ever ...
2
votes
2answers
1k views

How set ZFS ACL permissions on CentOS 6

I use last ZFS (ZFS for Linux) on the CentOS 6. Create successfully pool, all working fine. But i have one question. How i can set ACL for ZFS folder/file? GNU ls, chmod, and other coreutils not ...
6
votes
2answers
721 views

How can I validate a ZFS snapshot image residing on a backup system?

I'm running a FreeBSD host with ZFS. Let's pretend that I am storing a series of incremental ZFS snapshot images on a remote host using zfs send: zfs send -i zpool/data/foo@04hoursago zpool/data/...