ZFS out of space

[valluaho]

Hi all!

I have huge problems with my setup. I use Freenas 8.2 P1 and I have ZFS raidz1 with 8 500Gb disks. I use iSCSI to connect them to my vmware cluster. 5 x 560Gb targets.
Problem is that out of nowhere, mys zfs volume is 100% full. It's now 8Gb. I don't know why this is happening?

Here is my setup now.
https://docs.google.com/open?id=0B9i2kbCOHaXicVpwQTQ3TE9rMVk

First line, used about 200Mb, size 8.2Gb. When problems occurs, size is same as used, about 200Mb So no free space. Where does that 8Gb go? Don't understand... Theres also ftp about 48Gb, i can make it smaller and then after reboot, everything is ok.So every virtualmachine stalls and i cannot do anything. We have 200 VM:s that use freenas.

Any help? Would Freenas 8.3 upgrade help?

 

[jgreco]

So. It looks to me like you've allocated all your space and now are feeling pain. But I hate reading these things and trying to interpret them.

If you have 8 500GB disks, that works out to probably around 3045GB of usable space (remember a "500"GB disk is actually less, and RAIDz1 eats an entire disk, so this is more like 7 * 435GB). Minus 5 560GB extents, you have 245GB free. Minus 48GB for "ftp" and 158GB for "imaget" and maybe you'd have 39GB free. Well, your system's reporting less, but the 87% multiplier for mfr-to-real-value is only approximate anyways.

Did nobody tell you that you should not run a ZFS pool at full capacity? Because basically you've allocated approximately all your space, or so it appears to me, and then of course it's all downhill from there. Running a ZFS pool at more than 80% is a recipe for poor performance. I'd suggest for iSCSI a lower number.

 

[valluaho]

Ok, can you tell me why this is happening?

https://docs.google.com/open?id=0B9i2kbCOHaXiaVN2TDlpczk5MFU

In that screenshot, i have allready edited and editing "ftp" dataset again. I input 30G and press "edit dataset". 30G values does not get applied. How come? Same thing at "imaget". I don't understand why?? I've tried Quotas as well and that does not work either. bug or what?

So. It looks to me like you've allocated all your space and now are feeling pain. But I hate reading these things and trying to interpret them.

If you have 8 500GB disks, that works out to probably around 3045GB of usable space (remember a "500"GB disk is actually less, and RAIDz1 eats an entire disk, so this is more like 7 * 435GB). Minus 5 560GB extents, you have 245GB free. Minus 48GB for "ftp" and 158GB for "imaget" and maybe you'd have 39GB free. Well, your system's reporting less, but the 87% multiplier for mfr-to-real-value is only approximate anyways.

Did nobody tell you that you should not run a ZFS pool at full capacity? Because basically you've allocated approximately all your space, or so it appears to me, and then of course it's all downhill from there. Running a ZFS pool at more than 80% is a recipe for poor performance. I'd suggest for iSCSI a lower number.

 

[jgreco]

I'm not really sure what you're trying to do. In any case, I would strongly suggest that you might want to consider not having those two datasets there if you want to be assured of reasonable performance out of your FreeNAS. You should really keep at least 20-25% of your space free to ensure decent performance, and with iSCSI, I suggest *more*.