NC space issue (ZFS?)

NC: 20.0.4
OS: Ubuntu 20.04

I deployed this NC VMware appliance a while back, and it’s been working well, and I added a 500GB vDisk for /mnt/ncdata. What I’ve noticed though is that free space has been dropping dramatically - way faster than the amount of data on the system. I’ve cleared all trash, and checked for other potential issues - but I think it’s a ZFS problem. Right now, from the 500GB disk, NC reports the disk as 225GB in size with 73GB free. ZFS snapshots aren’t enabled (I’ve checked), so not sure what’s going on here. Can I re-claim this space?

Thanks for any advice.

Good morning mate, hope you are doing well…

Are you using LVM?

If not, you should look into using it, it’s a best practice for VMWare’s machines.

I wish I could help with your problem here, but my suggestion is to reinstall it on a LVM disk.

Good luck and have a nice week.


Yeah, sounds like a zfs issue. This is why you shouldn’t use crap filesystems.

how does that part of your comment help here?
Well let me answer my own question: it doesn’t. So please… try to be informative AND helpful at the same time with your answers.
Thank you.

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if you think it might be a problem of ZFS - it would mean - at the same time - that it’s no nc-problem.

if you’d think it might be a nc-problem though we’d need a bit more info about your server, environment, etc (as the template demanded here before you decided to delete it)

other than that: welcome to the user-forum of NC :wink:

Thanks for the replies. To clarify, this was deployed from a NC Vmware appliance, and I stepped through the installer and then did a bit of post-config. Nice easy setup, and I didn’t chose ZFS, that’s that the appliance configured the storage as. I wouldn’t normally use ZFS (I have my concerns about it too), but that’s where I am. Initially, all looked ok, but even if I do a df -h on the appliance, it shows the disk size as 226GB, but fdisk -l shows the disk correctly sized as 500GB. Damn ZFS, but I’m stuck with it now. I could run out of space here very quickly, when there should be >300GB free.

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Not sure if this is an option, but if I added a new EXT4 or XFS formatted disk, and migrated the /ncdata over to it, would that work? Here’s the output from zpool list;

ncdata 496G 406G 90.1G - - 11% 81% 1.00x ONLINE -

Why is over 400G allocated?

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Ok, it was snapshots, which I believe is a common culprit with ZFS. Looks like the NC appliance enables this by default, so they were chewing through space at a rate. I didn’t think it was initially as the command I was using didn’t show any, but apparently that had been depreciated, and there was a new command. Anyhow, to delete all the snapshots, I used;

zfs list -H -o name -t snapshot | xargs -n1 echo zfs destroy

Now I just need to work out how to turn them off completely!

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