Overview of a logical allocation of thin provisioned SRs
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Hello great gurus of XCP-ng and XO!
Today I got myself into a "little" trouble by accidentally overcommitting my thin provisioned SR, because I falsely believed there's enough space for the theoreticaly-full VDIs I was migrating into it. While that eventually succeeded, later some VDIs grew and the whole space got depleted, and so the VMs ended up with a ro filesystems
Call me gullible, but I did so because I believed (for reasons I blame myself) this little green graph shows the sum of VDI sizes and not the real filesystem allocation.
Take e.g. the VDI I hovered over -
kube-demo01-worker03
, where it shows 12.32 GiB. When I switch to the "Disks" tab, I see its size to be 100 GiB:
I think that it's nice to be able to see what's the real allocation sum of the thin provisioned VDIs, but I believe I also need to know when I will overcommit the space when adding more VDIs. A sum of the VDI full sizes would be a big help, but I haven't found it. Did I miss it somewhere? If not, could that be possibly added? I hope we could elaborate on how.
Thanks!
Vit Zikmund -
Hi!
It is possible to get that info, however, having over commit is normal, what really matters in the space used. Here, you have 280GiB free.
Maybe there's even an issue opened on this, have you searched on XO GH repo?
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Oh, thanks @olivierlambert, there indeed is such an issue: https://github.com/vatesfr/xen-orchestra/issues/3915
In the meantime I scratched together a little oneliner to figure out the right number:
SR='sr-name-label=<sr-name-label>' # or SR='sr-uuid=<sr-uuid>' xe vdi-list "$SR" is-a-snapshot=false params=virtual-size | grep '[^[:space:]]' | sed 's/[^:]*: //' | awk '{s+=$1} END {print s/1024/1024/1024 " GiB"}'
It ignores snapshots, but that's OK for me.
Anyways, I'll try following up in the issue. Thanks again
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Please add a comment, so we won't forget this and put it into XO Lite and XO 6
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Hello @olivierlambert, I've put a comment to the issue. Was it what you expected? The issue itself seemed rather abandoned and nothing moved there since the comment. Is that to be expected? I don't want to sound disrespectful, I know all this is best-effort, but you react surprisingly often! Just want to make sure I didn't miss anything. Some of the changes I suggested I could maybe hand over in a (lame) PR, if such an effort would be appreciated.
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That's because the effort to change this will be taken into account in XO 6
Alternatively, you can indeed contribute, this will be very welcome!