new disks in zfs - is it possible?

[TauriRed]

I'm new to ZFS on Proxmox.

one of nodes have:
- 250 Gb boot ssd (with /boot, local / local-lvm on it)
- 1 Tb SSD with ZFS (added post-install), with one
Can I add another disk to just extend available space on pool (without any extra redudancy, I have PBS-based backups)?
I'm correct that I just need to install new disk, and use zpool add main_local /dev/sdX to add it to pool and it will be used to increase available space in pool?




root@pve2:~# zpool status
pool: main_local
state: ONLINE
config:

NAME STATE READ WRITE CKSUM
main_local ONLINE 0 0 0
ata-HP_SSD_S750_1TB_HBSA43500100287 ONLINE 0 0 0

errors: No known data errors


root@pve2:~# zfs list
NAME USED AVAIL REFER MOUNTPOINT
main_local 867G 55.8G 104K /main_local
main_local/subvol-1338-disk-0 1.53G 6.47G 1.53G /main_local/subvol-1338-disk-0
main_local/subvol-3003-disk-0 2.33G 5.67G 2.33G /main_local/subvol-3003-disk-0
main_local/subvol-600-disk-1 1.85G 6.15G 1.85G /main_local/subvol-600-disk-1
main_local/vm-101-disk-0 6.05M 55.8G 56K -
main_local/vm-101-disk-1 538M 56.3G 15.7M -
main_local/vm-2003-disk-0 92.5G 121G 27.5G -
main_local/vm-2003-disk-1 3.14M 55.8G 144K -
main_local/vm-2003-disk-2 6.07M 55.8G 68K -
main_local/vm-300-disk-0 39.3G 88.4G 6.72G -
main_local/vm-3001-disk-0 172M 56.0G 39.6M -
main_local/vm-400-disk-0 79.4G 105G 30.7G -
main_local/vm-702-disk-0 190G 186G 60.0G -
main_local/vm-888-disk-0 459G 348G 166G -

root@pve2:~# df -h
Filesystem Size Used Avail Use% Mounted on
udev 24G 0 24G 0% /dev
tmpfs 4.7G 2.0M 4.7G 1% /run
/dev/mapper/pve-root 67G 4.3G 59G 7% /
tmpfs 24G 76M 24G 1% /dev/shm
tmpfs 5.0M 0 5.0M 0% /run/lock
efivarfs 256K 56K 196K 23% /sys/firmware/efi/efivars
/dev/nvme0n1p2 1022M 12M 1011M 2% /boot/efi
main_local 56G 128K 56G 1% /main_local
main_local/subvol-1338-disk-0 8.0G 1.6G 6.5G 20% /main_local/subvol-1338-disk-0
main_local/subvol-600-disk-1 8.0G 1.9G 6.2G 24% /main_local/subvol-600-disk-1
main_local/subvol-3003-disk-0 8.0G 2.4G 5.7G 30% /main_local/subvol-3003-disk-0
/dev/fuse 128M 76K 128M 1% /etc/pve
//xitarri.viorsan.com/VMs 5.3T 3.9T 1.4T 75% /mnt/pve/xitarri
tmpfs 4.7G 0 4.7G 0% /run/user/0

 

[LnxBil]

Can I add another disk to just extend available space on pool (without any extra redudancy, I have PBS-based backups)?
I'm correct that I just need to install new disk, and use zpool add main_local /dev/sdX to add it to pool and it will be used to increase available space in pool?

Yes.

 

[Kingneutron]

The short answer is yes. You would however have a RAID0 equivalent; if one disk dies, the whole pool goes. And you would not have self-healing scrubs, but you could do copies=2 for critical datasets.

If down the line you get 2x more same-sized SSDs, you could attach them one at a time as a mirror to each original disk, wait for resilver to finish, and end up with a RAID10 equivalent (pool of mirrors.) You would then have self-healing scrubs.