Partitioning questions in Proxmox 4.x

[sam1994]

Hi,

We're using Proxmox 4.x with both LXC containers and KVM
machines. It seems that the way partitioning is handled has changed
since Proxmox 3.x.

We have some data that we need to share between a few of these
LXC containers; so I have a set up mp0 in /etc/pve/lxc/*.conf for
each container and I have the directory on the host itself.

I need to grow the size of the root partition as a result, and it seems
that the partitioning is still configured via LVM. This is where seems to get
slightly confusing. I've grown the root partition with lvextend as much as
possible.

vgdisplay shows that I don't have many free extents left:

VG Size 418.50 GiB
PE Size 4.00 MiB
Total PE 107135
Alloc PE / Size 106918 / 417.65 GiB
Free PE / Size 217 / 868.00 MiB
VG UUID PU2dFV-j0mq-aSo8-RPgk-yc2z-3UQ2-46iVqW

It's unclear where the extents are allocated. I'm still able to create
containers. Can anyone advise how I can create more space for the
root partition?

Furthermore, I'm now slightly concerned about the best backup strategy.
I am using Bacula, which backs up at a file system level rather than
the block level.

I can see now that LXC containers use logical volumes for storage. Previously
with Proxmox 3.x and OpenVZ, I believe that all filesystems were under /var/lib/vz.

I checked and can see volumes such as /dev/pve/vm-110-disk-1.
I've checked /proc/mounts and can't see them mounted anywhere. Where are
they mounted? I'd like to make sure that backups are indeed working correctly.

I don't have a lot of non-ephemeral data inside my containers, but
I am wondering if it's better to mount that data outside on / so that it can
definitely be backed up correctly.

Thank you in advance

 

[LnxBil]

Partitioning is always the same, but you mean LVM. The system is still on LVM (if not on ZFS or something else). The data is now stored inside of a thin LVM pool to only use space that is used. You can revert back to the old scheme with a volume in /var/lib/vz here:

https://pve.proxmox.com/wiki/LVM2#Create_a_extra_LV_for_.2Fvar.2Flib.2Fvz

 

[sam1994]

Hello,

I apologise for the late reply (Summer has delayed things).

Thanks for clarifying that newer versions of Proxmox now employ thin provisioning. I wasn't aware of this.
Is there a way for me to migrate these containers to the old scheme without destroying them? I can accept
downtime for the containers but don't want to lose the contents. Should I snapshot them all and restore them
back?

Thank you

 

[LnxBil]

Is there a way for me to migrate these containers to the old scheme without destroying them?

Containers cannot (yet) be migrated, they have to be backuped and restored to a new storage, and yes, this means downtime.

Can anyone advise how I can create more space for the
root partition?

Have you only run lvextend and not resize2fs or both? Please post in CODE tags the output of lvs and df -T

 

[sam1994]

Hi

I found a new solution: shrink / and use lvcreate using
pve/data VG, and then mounting it as a bind.