Questions tagged [zfs]

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 fork of ZFS can be found at http://open-zfs.org/ , which is supported by ZFSonlinux.org, illumos.org and ZFS developers in the FreeBSD & Mac OS X communities.

ZFS is supported out of the box on a number of operating systems:

  • Solaris 10
  • Oracle Solaris 11 Express
  • FreeBSD
  • NexentaStor
  • illumos - specifically, illumos-based distributions, like:
    • Nexenta's illumian
    • Joyent's SmartOS (server OS with strong focus on virtualization)
    • OmniTI's OmniOS (general purpose server OS)
    • OpenIndiana (general purpose desktop/server OS)

Due to license incompatibilities, the CDDL licensed ZFS code cannot be distributed as part of the GPL licensed Linux kernel. Other alternatives methods are available for running ZFS on Linux:

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Does ZFS in mirror mode double vdev read performance?

I'm not able to find a clear yes/no answer to this simple question: does using ZFS in mirror mode double the read performance of the underlying vdevs? This applies to either individual requests or net performance (i.e. a single read request is…
Mahmoud Al-Qudsi
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Is it possible to detach and reattach a ZFS disk without requiring a full resilver?

I have a ZFS mirrored pool with four total drives. Two of the drives are intended to be used for rotating offsite backups. My expectation was that after the initial resilvering I could detach and later attach a disk and have it only do an…
STW
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Need to replace disk in zpool ... confused

I need to replace a bad disk in a zpool on FreeNAS. zpool status shows pool: raid-5x3 state: ONLINE scrub: scrub completed after 15h52m with 0 errors on Sun Mar 30 13:52:46 2014 config: NAME STATE …
Dan
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How to use a file as a zpool?

If I do dd if=/dev/zero of=/tank/test/zpool bs=1M count=100 how can I treat the file /tank/test/zpool as a vdev, so I can use it as a zpool? It is for zfs testing purposes only.
Jasmine Lognnes
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FreeNAS, Do I need 1GB per TB of usable storage, or 1GB of memory per TB of physical disc?

The title says it all. When setting up free NAS, do I need 1GB per TB of usable storage, or 1GB of memory per TB of physical disc?
Litzner
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How to run a command once a ZFS scrub *completes*?

I would like to use cron to schedule periodic scrubs of my ZFS pool, and at some reasonably short time after the scrub finishes, email a status report to myself. The purpose of this is to catch any problems without having to manually look for them…
user
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Can I move a ZFS pool to another computer?

I have an EasyStore NAS running Ubuntu, and I want to replace the disks. I want to add the ZFS kernel modules and create a ZFS RAIDZ pool. Due to space constraints, I have to move the data to the new pool right away. Can I create the new pool on…
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Technical details for Server 2012 de-duplication feature

Now that Windows Server 2012 comes with de-duplication features for NTFS volumes I am having a hard time finding technical details about it. I can deduce from the TechNet documentation that the de-duplication action itself is an asynchronous process…
the-wabbit
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ZFS: How do you restore the correct number of copies after losing a drive?

With zfs, if you have copies=2 and then you lose a drive containing some of those copies, how do you tell the system that it should make a new copy of the data blocks for the affected files? Or does zfs just start adding data blocks for the extra…
James Moore
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ZFS: Removing files from snapshots?

Say I have a dataset with 100 snapshots and want to rm -rf all folders named "cache" in all snapshots. I want to actually free up the space, not just hide it away in layers of snapshots, so making a clone and removing from that and then taking a new…
Tino Didriksen
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ZFS Like Alternatives on Windows

Conceptually, and I don't think I am alone here, I love the concepts of ZFS. You can create one big disk, everything is stored on multiple drives, and you can grow and shrink the pool and drive at any time. Plus, the disks don't need to be same…
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How can I determine what permissions my user is missing for receiving a ZFS dataset?

I have a FreeNAS (11.1-U1) and a FreeBSD (11.1-RELEASE-p6) machine. On the FreeNAS I'd like to zfs receive recursive snapshots as a non-root user with delegated privileges. This appears to work well for most of the child-datasets. But iocage's data…
sloh
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ZFS hot spares versus more parity

I am a bit new to ZFS but I am bringing up a new storage pool with 12 physical drives. My current plan is to have RAIDZ2 across 10 drives and two hot spares. But I wonder if I would not be better off with RAIDZ3 across all 12 drives and no hot…
AlanObject
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Cannot destroy ZFS snapshot: dataset already exists

I have a server (T5220, though I doubt it matters) running Solaris 10 8/07 and I have a ZFS pool, "mysql", on internal disk. Within it I have a filesystem "mysql/data/4.1.12", which I snapshot hourly with a script from cron. I have one snapshot,…
Morven
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Are ZFS pools or LVM volume groups more reliable for utilizing many partitions?

When deciding whether to use LVM volume groups or ZFS pools in configuring new file servers, what needs to be considered? Is there a "better" choice in the realm of multi-purpose file servers? Unlike this previous question, I don't want to layer the…
warren
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