I'm using ProxmoxVE and I would like to run some benchmarks regarding performances of this product. One of these benchmarks is bonnie++ ; it runs very well in a VM (qemu-kvm) but when I run it in a conainer (openVZ), it does not provide me reading speed (only writing).

I don't understand why... Does anyone know what's happenning ?

VMs ans Containers are Debian 7.4. Here's the output of bonnie in the container:

root@ct2:/# bonnie++ -u root
Using uid:0, gid:0.
Writing a byte at a time...done
Writing intelligently...done
Reading a byte at a time...done
Reading intelligently...done
start 'em...done...done...done...done...done...
Create files in sequential order...done.
Stat files in sequential order...done.
Delete files in sequential order...done.
Create files in random order...done.
Stat files in random order...done.
Delete files in random order...done.
Version  1.96       ------Sequential Output------ --Sequential Input- --Random-
Concurrency   1     -Per Chr- --Block-- -Rewrite- -Per Chr- --Block-- --Seeks--
Machine        Size K/sec %CP K/sec %CP K/sec %CP K/sec %CP K/sec %CP  /sec %CP
ct2              1G   843  99 59116   8 60351   4  4966  99 +++++ +++  2745   8
Latency              9558us    3582ms     527ms    1672us     936us    5248us
Version  1.96       ------Sequential Create------ --------Random Create--------
ct2                 -Create-- --Read--- -Delete-- -Create-- --Read--- -Delete--
              files  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP  /sec %CP
                 16 +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++ +++++ +++
Latency             19567us     358us     368us     107us      59us      25us

The filesystem for / is of type "simfs", which is a pseudo filesystem for openVZ. Maybe it's related to this issue but I can't find anyone with the same issue with bonnie and openVZ...

Thanks for your help.




Could you show this command output: cat /proc/mounts from you VPS?

There are two disk layout for OpenVZ: 1) simfs (old, obsolet; it's not an block device it's only folder on physical server) 2) ploop (new, recommended; it's block real device with separate filesystem)

But on both cases you haven't direct access to block device (like /dev/loopX). But you may call your provider to provide it but keep in mind it's very insecure.

  • Here's the command output: # cat /proc/mounts /dev/simfs / simfs rw,relatime 0 0 proc /proc proc rw,nosuid,nodev,noexec,relatime 0 0 sysfs /sys sysfs rw,nosuid,nodev,noexec,relatime 0 0 tmpfs /run tmpfs rw,nosuid,noexec,relatime,size=104860k,mode=755 0 0 tmpfs /run/lock tmpfs rw,nosuid,nodev,noexec,relatime,size=5120k 0 0 tmpfs /run/shm tmpfs rw,nosuid,nodev,noexec,relatime,size=314560k 0 0 devpts /dev/pts devpts rw,nosuid,noexec,relatime,gid=5,mode=620,ptmxmode=000 0 0 My filesystem is simfs... I think this explains why bonnie can't perform block read test. Thanks for your explanations :) – Rabbit Jun 19 '14 at 11:47
  • Unfortunately, your VPS haven't any block device attached (simfs is only folder on physical server over ext3/ext4 filesystem) to it and you can't use bonnie for block device testing. – Pavel Odintsov Jun 19 '14 at 13:12
  • You can try another tool like fio: freecode.com/projects/fio it can test I/O speed without access to block device. – Pavel Odintsov Jun 19 '14 at 13:27

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