[Users] OpenVZ Legacy: New simfs quota issues?

[Michael Stauber]

Hi all,

We just set up a CentOS 6.7 with OpenVZ (legacy) and encountered some
quota / smifs related issues that we haven't had before. Yes, we know
about the advantages of "ploop", but we're slow adopters and so far are
still preferring "simfs" due to some legacy stuff.

Here is the setup in a nutshell:

Kernel: 2.6.32-042stab113.11 on CentOS 6.7, fully YUM updated.

NODE]# rpm -qa|grep vz
vzdump-1.2-17.x86_64
vzquota-3.1-1.x86_64
vzstats-0.5.3-1.noarch
vzctl-core-4.9.4-1.x86_64
vzkernel-2.6.32-042stab088.4.x86_64
vzkernel-devel-2.6.32-042stab113.11.x86_64
vzkernel-2.6.32-042stab113.11.x86_64
vzkernel-devel-2.6.32-042stab088.4.x86_64
vzkernel-firmware-2.6.32-042stab113.11.noarch
vzctl-4.9.4-1.x86_64

The box uses 2x 200GB SSD's with hardware-RAID1:

NODE]# cat /etc/fstab
/dev/mapper/sysvg-root  /         ext3   defaults        1 1
UUID=XXXX               /boot     ext3   defaults        1 2
/dev/mapper/sysvg-vz    /vz       ext3   defaults        1 2
/dev/mapper/sysvg-swap  swap      swap   defaults        0 0
tmpfs                   /dev/shm  tmpfs  noexec,nosuid,rw  0 0
devpts                  /dev/pts  devpts gid=5,mode=620  0 0
sysfs                   /sys      sysfs  defaults        0 0
proc                    /proc     proc   defaults        0 0

Upon creation of a VPS with "simfs" and 2nd level disk quota enabled the
quota inside the VPS doesn't work:

VPS]# mount
simfs on / type simfs (rw,relatime,usrquota,grpquota)

VPS]# useradd admin
VPS]# edquota admin
edquota: Cannot stat() mounted device simfs: No such file or directory
No filesystems with quota detected.

I tried all the usual stuff such as dropping / re-adding the VPS quota,
running quotacheck and quotarep and such ... no joy.

As this wasn't a production box yet I then converted /vz from EXT3 to
EXT4 and converted the VPS from "simfs" to "ploop" using "vzczl convert
<CTID>".

What can I say? After starting that VPS quota immediately worked.

Deploying another VPS with 2nd level disk quota enabled and directly
choosing to create it with "ploop" instead of "simfs" also results in
functioning 2nd level disk quota.

My question: Did something get changed intentionally or unintentionally
so that "simfs" now no longer works with 2nd level Quota? Or maybe it's
an SSD thing, as this is our first OpenVZ (legacy) with /vz on SSDs.

Any pointers? Many thanks!

-- 
With best regards

Michael Stauber