Combining Disks

[KingAllen]

Hi, how can I combine/add my 3 storage into 1 storage. I have 3x300gb storage and I want to make it 900gb, is it possible to do this?


or how can I add this into my existing VM storage without losing my data. Thank you.

 

[Dunuin]

Thats a JBOD or raid0 and the PVE webUI won't allow you to do this as this is dangerous (lose one disk and everything is lost...so multiple times higher chance to lose all your data compared to just using a single 900GB disk). You could still manually create that using the CLI via LVM/mdadm/ZFS/btrfs and then add a new storage pointing to it (at Datacenter -> Storage -> Add).

If you do anything other than testing I would get a forth disks to create a raid10 to get 600GB. If thats not an option I would create a raid5 to also get 600GB.

 

[KingAllen]

Thank you for your response.

I create ZFS for 4x300gb and it shows that I have now a 1.19TB, I choose RAIDZ2

but when I create a VM it shows that I only have 560.40gb



can you explain how this happen? sorry I am new here in proxmox world. Thank you.

 

[Dunuin]

I create ZFS for 4x300gb and it shows that I have now a 1.19TB, I choose RAIDZ2

Raidz2 is raid6, so 2 disks for data, 2 for parity = 600GB usable (which you shouldn't fill more than 480GB). The 1,2TB is the raw capacity

 

[KingAllen]

Thank you @Dunuin! I can now understand.

 

[Kingneutron]

For such small drive sizes, raidz2 is probably overkill and wasting disk space. You could rebuild it as raidz1

Raidz2 is commonly recommended for spinning drive sizes over 2TB, mostly due to the chance of a 2nd drive failing during rebuild and the time it takes to resilver.

At any rate though, you should always have regular backups of your zfs pool so you can restore if the whole thing decides to go poof

 

[Dunuin]

And striped mirror aka raid10 if you care about performance.