Problem I/O overload

[phosting]

Hi all, I wanted to open a post about a problem you're having with all versions of Proxmox with OpenVZ. When a virtual machine consumes I / O there is no limitation in this regard, for example, if a virtual machine makes a backup, can consume all the I / O server load by making the overall rise considerably and reentilizando entire server, so like all machines. I've tried with:
# Vzctl set ID - ioprio 0 - save

But no use. Has anyone had this problem?

Very thanks

 

[dietmar]

How do you backup - with vzdump?

 

[phosting]

No, inside a virtual machine doing a simple tar.gz of many files. Do not even have to be root, any user who performs a backup(inside virtual machine) of more than 5GB overload the physical server. The problem is that it does not limit the openvz i / o in any way, it happens in all versions of Proxmox.

Thanks for your help

 

[dietmar]

And the container uses local storage with ext3? (/var/lib/vz/)

 

[dietmar]

BTW, OpenVZ only allows you to set io priorities, no absolute limits.

If you need absolute limits, use KVM instead.

 

[dlasher]

BTW, OpenVZ only allows you to set io priorities, no absolute limits.

If you need absolute limits, use KVM instead.

I'd agree this is something that proxmox should be able to improve upon.

I recently migrated a dozen or so KVM's to VZ, and have had to work around some of the more serious IO challenges. While things like nice and ionice can help, heavy IO on a single VZ can still bring the entire machine to its' knees, which didn't happen when they were KVM's.

I'm tempted to attach a dedicated disk for one specific VZ, which somewhat defeats the purpose of having everything running on a raid array, but for now I can't see any other way to limit the IO, short of converting back to a KVM. I too welcome any suggestions.