Convert LXC containers to OpenVZ containers

[alex3137]

Hello.

Due to number of issues with PVE 4 and LXC, I would like to downgrade to Proxmox 3.4.

Is it possible to convert an LXC container to an OpenVZ container ?

Thank you

 

[tom]

there is no tool for this.

which LXC issues? please add a link (e.g. to the bugreport)

 

[alex3137]

Hello @tom

My main problem is performance issues (IOwait) and I opened a thread here. Some other users experiencing similar problem here, there, there too.

This is very frustrating because it seems to be an issue for a lot of people and Proxmox staff does not really react to the problem. Maybe you are clueless like us, but given the number of users affected it cannot be ignored forever. I am willing to help troubleshooting but we need support from Proxmox team.

 

[LnxBil]

Did you try to tweak the barriers as it is described everywhere?

I installed several machines in the last two weeks (all with ZFS) and never had any performance problems. I do know that I had to tweak the barriers back in the days of my XEN virtualization, which suffered from similar problems. ext4 is not optimal and you definitely do not need another storage layer if you use LXC. Just use ONE filesystem which is faster.

 

[alex3137]

I am using ext3 and disabled barriers the following way in /etc/fstab:

/dev/pve/data   /var/lib/vz     ext3    defaults,barrier=0,data=writeback       1       2

 

[LnxBil]

And your containers? Are they RAW/QCOW2 or files in the filesystem?

 

[alex3137]

My containters are file on the filesystem (I create them from Proxmox GUI, backup them and restore them with --rootfs local:0)

 

[LnxBil]

Have you looked in the upstream kernel bugreport for similar issues? Kernel is IMHO unchanged, so there should be similar issues on Ubuntu too.

 

[tom]

LXC on ext3 is not the setup I would recommend. LXC storage setup is totally different to the old openvz storage, so you cannot do it the same.

Try ZFS - if you follow the hardware recommendations for ZFS, you will see great performance (and features).

 

[alex3137]

LXC on ext3 is not the setup I would recommend. LXC storage setup is totally different to the old openvz storage, so you cannot do it the same.

Try ZFS - if you follow the hardware recommendations for ZFS, you will see great performance (and features).

I run a standalone server with one hard drive and 3 partitions: OS, data, backups. I saw ZFS is not recommended in this configuration because of a risk of corruption . Can you advise which filesystem is appropriate in my setup ?

 

[tom]

if you want performance, you will need to use the appropriate hardware.

A single hard drive give you exactly the performance of a single hard drive and yes, ZFS is not possible here.