# [FreeNAS] Is a ZFS pool confused when adding disks to a computer?



## bengtv (Jun 11, 2011)

I'm using FreeBSD based FreeNAS 8.0. I first created a 4x2TB ZFS raidz array using the FreeNAS GUI. Everything seemed ok. I then added a 2 port SATA PCI-e card and attached a 2TB disk and a 60GB SSD. I saw no complaints when booting, but the new disks seemed to be detected first, so the disk names changed. And when I started the FreeNAS GUI again, it suggested I had TWO! 2TB disks available for creating new ZFS volumes. :-O

So, my question is: does a ZFS pool survive disks moving around due to changed detection order (using meta-data), or is it necessary to label them or something?

Note: In case this IS handled by ZFS itself, then FreeNAS has a serious bug in its GUI when managing volumes... 

/Bengt


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## usdmatt (Jun 11, 2011)

ZFS works using purely metadata stored on the disks. It doesn't matter what the device names are. I expect that your 4 disk pool is probably working fine still?

Is sounds like the issue is with the FreeNAS GUI but you'll probably have to ask on the FreeNAS forum to get any help with that. I have no idea how the FreeNAS GUI determines which disks are available and which disks are in use.


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## bengtv (Jun 11, 2011)

usdmatt said:
			
		

> ZFS works using purely metadata stored on the disks. It doesn't matter what the device names are. I expect that your 4 disk pool is probably working fine still?
> 
> It sounds like the issue is with the FreeNAS GUI but you'll probably have to ask on the FreeNAS forum to get any help with that. I have no idea how the FreeNAS GUI determines which disks are available and which disks are in use.



Well, at least it seemed to be working... which felt a bit odd considering the GUI obviously thought the 60GB SSD was part of the pool. I think I will have to turn to the FreeNAS developers or issue a bug report on that GUI thingy. 

Thanks!


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