ZFS Install

Installation and creation of a new ZFS pool.

Install ZFS tools.
apt install zfsutils-linux
Install RAM FS tools if ZFS is to be used for the root filesystem as well.
apt install zfs-initramfs

Note

The HWE kernel currently does not build properly for Ubuntu, you need to use the generic kernel until this bug is resolved.

Creating New ZFS Pool

Best practice from years of ZFS use are:

  • Use an unecrypted ZFS pool.

  • Create datasets to handle specific data needs/types/etc. Keep massive files in one dataset (e.g. videos), versus one for running services.

  • Set dataset options based on those needs (encryption, compression, etc). This isolates master encryption keys and makes data management easy years later.

  • Set mountpoints immutable chattr +i {MOUNTPOINT} when dataset is not mounted. This prevents writing to those mountpoints when the pool/dataset is not mounted or unlocked.

See Encryption.

Determine disks to add to ZFS pool.
lsblk
ls -l /dev/disk/by-id

Note

ZFS will handle the paritioning of raw disks automatically. There is no need to explicitly partition your disks beforehand.

Do not encrypt the root pool, or mount it. Encrypt and mount datasets instead. See Encryption.

Create a ZFS pool.
zpool create -o autoexpand=on -o ashift=12 -O mountpoint=none {POOL} raidz2 /dev/disk/by-id/wwn-*
zpool list
zpool status {POOL}
zdb -C {POOL}

  • autoexpand=on enables auto-expanding of ZFS pool when new disks are added.

  • ashift=12 Enables 4K sectors. All > 2011 drives should have 4K sectors. This cannot be changed once set in the pool, and will lead to severe performance degradation if mis-matched for FS/drives. Cannot hotswap/replace 512 with 4K drives in pool.

  • -O mountpoint=none the unencrypted pool will not be mounted; mount datasets instead.

  • raidz2 preferred for 6+ disk arrays. raidz for <6.

  • www-* replace with bash expansion to match drives to use. Can specify multiple block devices explicitly.

  • With -C option, ensure ashift=12 is enabled.