14-drive RAIDZ3: how bad?

[Z300M]

At present one of my pools has two 7-drive RAIDZ2 vdevs, but I'm wondering about changing to a single 14-drive RAIDZ3 vdev for a little more storage space. How inadvisable would this be?

 

[Jailer]

Hopefully @cyberjock will be along shortly to share his experience of his wide vdev pool testing. He was not a fan.

 

[cyberjock]

Well, I'll put it to you this way:

I did it, and I regretted it after I moved all my data to the zpool. Early benchmarks seemed okay, but as you fill a zpool performance drops quickly. I had to destroy the zpool and recreate it (which I did).

• I'd never do it again under any circumstances.

• I'd never recommend doing it again under any circumstances, even backups.

• I'd never bother to troubleshoot a system that did it because of the odd performance issues that are very hard to diagnose and work around.

Does that answer your question? ;)

 

[Z300M]

Well, I'll put it to you this way:

I did it, and I regretted it after I moved all my data to the zpool. Early benchmarks seemed okay, but as you fill a zpool performance drops quickly. I had to destroy the zpool and recreate it (which I did).

• I'd never do it again under any circumstances.

• I'd never recommend doing it again under any circumstances, even backups.

• I'd never bother to troubleshoot a system that did it because of the odd performance issues that are very hard to diagnose and work around.

Does that answer your question? ;)

OK, I get the message. I'll leave it the way it is.