Advise on Growing our ZFS Pool

[FredK]

I currently have Promox 8.1 installed here. Proxmox boots from a separate pool from the one that I would like to grow/expand. The pool I wish to expand is used for OS and data storage for several VMs and containers. The current ZFS pool is formatted as a single RAIDZ2 pool using 8 SAS SSDs. I wish to create a second, identical RAIDZ2 pool using an additional 8 SSD SAS SSD drives which are identical to those in the current RAIDZ2 pool and they use both RAIDZ2 pools together in a RAID-Z20 configuration (i.e. the two RAIDZ2 pools combined as a RAID-0). I have backups for all of my VMs and LXCs so I could just wipe everything out and start over but it would be better if I could expand/enhance my existing single-RAIDZ2 pool that is running now. I am looking for some advice on how to go about this along with some informtion on the steps that I need to follow to setup the RAID-Z20 portion of the final storage system in Proxmox.

 

[Dunuin]

See the zpool add command: https://openzfs.github.io/openzfs-docs/man/master/8/zpool-add.8.html
So something like "zpool add YourPool raidz2 /dev/disk/by-id/yourdisk9 /dev/disk/by-id/yourdisk10 ..."

 

[alexskysilk]

Just be aware that when adding a vdev to an existing pool, the pool will NOT REBALANCE, which means you will not gain any performance for existing data, and may interfere or even prevent new data from being properly striped across vdevs. best practices suggest removing the data before growing the pool, and writing it back afterwards.

 

[Himcules]

Think best way is start brand new again and make use of striped RAIDZ2 as you intend. Will go something like this:

zpool create RAIDZ2 <8 vdevs> RAIDZ2<8vdevs>

NAME STATE READ WRITE CKSUM
data ONLINE 0 0 0
raidz2-0 ONLINE 0 0 0
wwn-0x50024e9204f42340 ONLINE 0 0 0
...etc
raidz2-1 ONLINE 0 0 0
wwn-0x50004cf210be5214 ONLINE 0 0
...etc

 

[FredK]

Thank you to everyone here for helping me with this! Based upon the advice provided, I was able to upgrade my current storage pool using the zpool add command and the procedure outlined at the following link: https://openzfs.github.io/openzfs-docs/man/master/8/zpool-add.8.html. With this done, I made backups of each of my VMs and LXCs, deleted them, and then recreated them from my backups. I also copied the files .iso and .gz files in my templates directory. The combination of these last two steps resulted in the storage between my two RAIDZ2 vdevs being almost perfectly balanced.

Thanks again everyone - the support here is fantastic!