I have a FreeBSD server which used to run of a smaller SSD drive. When replaced with a larger capacity SSD by using dd command to clone the disk, there is free space allocated. I want to extend the existing zroot pool to use this space. The following describes how I achieve this with the help of a forum post.
Let’s list some information about the zroot pool:
root@nas:~ # zfs list zroot
NAME USED AVAIL REFER MOUNTPOINT
zroot 4.88G 50.8G 144K none
List the partition scheme of the drive I’d like to extend my zroot zpool with:
root@nas:~ # gpart show
=> 34 488397101 ada4 GPT (233G)
34 1024 1 freebsd-boot (512K)
1058 4194304 2 freebsd-swap (2.0G)
4195362 120850029 3 freebsd-zfs (58G)
125045391 363351744 - free - (173G)
The first step is to resize the partition (I think it’ss called slice in FreeBSD term or something):
root@nas:~ # gpart resize -i3 /dev/ada4
ada4p3 resized
root@nas:~ # gpart show
=> 34 488397101 ada4 GPT (233G)
34 1024 1 freebsd-boot (512K)
1058 4194304 2 freebsd-swap (2.0G)
4195362 484201766 3 freebsd-zfs (231G)
488397128 7 - free - (3.5K)
-i3: index #3 in the partition table
Next check to ensure that the autoexpand property of the pool is set to on. If not then set it using zpool set autoexpand=on zfspoolname:
root@nas:~ # zpool get autoexpand zroot
NAME PROPERTY VALUE SOURCE
zroot autoexpand on local
My zroot pool’s autoexpand property has already been set to “on”;. Next I’m ready to expand my zpool. I should have mentioned that the device named I used for my zpool is /dev/gpt/zfs0. If it were something different, e.g. ada4p3, then adjust it accordingly:
root@nas:~ # zpool online -e zroot /dev/gpt/zfs0
root@nas:~ # zfs list zroot
NAME USED AVAIL REFER MOUNTPOINT
zroot 4.88G 218G 144K none
That’s it.
Ref: https://forums.freebsd.org/threads/extend-zfs-partition.55964/