Proxmox 4 - LXC - Disk Quota without raw image

[michaelj]

Hi everybody,

I'm facing a performance issue (iowait) since proxmox4 (same problem here : https://forum.proxmox.com/threads/high-wait-io-after-and-load-average-upgrade-to-proxmox-4.25128/)

Example configuration of one of my CT :

rootfs: local:221/vm-221-disk-1.subvol,size=0T

pct exec 221 df
dev/mapper/pve-data 1548053708 1008385824 461008300 69% / (LVM partition for proxmox data)
none 492 0 492 0% /dev
tmpfs 6587240 332 6586908 1% /run
tmpfs 5120 0 5120 0% /run/lock
tmpfs 838860 0 838860 0% /run/shm

I wouldlike to have for example something like this :

rootfs: local:221/vm-221-disk-1.subvol,size=20G

Is it possible to apply disk quota on CT without raw image format disk ?

Kind Regards

 

[tsumaru720]

Hi

For me this was a two fold thing - By default containers seem to use .raw files now - The same as you I started having io problems.

I found out how to make the container use the old OpenVZ method so the entire rootfs was visible from the host

/var/lib/vz/images/113/vm-113-disk-1.subvol/etc/apache2

for example. This did give me better performance but like you I lost my quota.

I was doing a bit of research and whilst I cant speak for yourself, I found on the forum a mention of ext4 and "barriers"... (Not the post I saw, but it is essentially the same thing: https://forum.proxmox.com/threads/ext4-barriers-0-to-do-or-not-to-do.17919/ )

In my case I opted to add "barrier=0" to my mount options for /var/lib/vz in /etc/fstab which should allow better performance whilst using RAW images.

Of course your mileage may vary and I don't run anything write intensive other than Observium (Lots of .rrd files being updated)

 

[michaelj]

Hi Simon,

Thanks to your answer, with this method