Poor performances on HP ML350 G6

[alexpacio]

Hi,
i have a proxmox 1.6 installation with 3 sas drives. I installed a windows 2008 in a 300GB 15k sas drive and i created a secondary virtual drive in a second sas drive. If i try to transfer i file, i get 2 MB/s of transfer rate. Both the virtual disks are in qcow2 with no compression, no encryption. When i do the copy, the OS is fully idle, and, while i'm copying the file, the VM doesn't respond anymore. I searched by Google about this problem and i found out that the SAS controller that i've installed on my server (HP Smart Array P410i) is known to have poor performances with the module i've loaded in the proxmox kernel. I also tried to update the P410i firmware, but it didn't solve the problem.

How can i solve it?

 

[tom]

pls post also the output of 'pveversion -v' and 'pveperf'

 

[alexpacio]

pveversion:
pve-manager: 1.6-2 (pve-manager/1.6/5087)
running kernel: 2.6.32-2-pve
proxmox-ve-2.6.32: 1.5-7
pve-kernel-2.6.32-2-pve: 2.6.32-7
pve-kernel-2.6.18-2-pve: 2.6.18-5
qemu-server: 1.1-18
pve-firmware: 1.0-7
libpve-storage-perl: 1.0-14
vncterm: 0.9-2
vzctl: 3.0.24-1pve4
vzdump: 1.2-7
vzprocps: 2.0.11-1dso2
vzquota: 3.0.11-1
pve-qemu-kvm: 0.12.4-1
ksm-control-daemon: 1.0-3


pveperf:

pveperf /mnt/srv2008_os/
CPU BOGOMIPS: 34134.22
REGEX/SECOND: 786097
HD SIZE: 246.08 GB (/dev/mapper/srv2008_os-os)
BUFFERED READS: 157.39 MB/sec
AVERAGE SEEK TIME: 5.44 ms
FSYNCS/SECOND: 59.75
DNS EXT: 4005.43 ms
DNS INT: 295.44 ms (cdlpg.eu)

 

[tom]

you do not have and write cache enabled on your raid volumes (FSYNCS/SECOND: 59.75). with sas disk you should got something around 1000 to 5000.

what is mounted on /mnt/srv2008_os/?

second, try our latest 2.6.32 kernel.

 

[alexpacio]

I have not enabled the write cache on the controller due to possible unsecurities of data loss by power losses.

here is df -h output:

vm2:/mnt# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/mapper/pve-root 15G 995M 13G 8% /
tmpfs 3.9G 0 3.9G 0% /lib/init/rw
udev 10M 780K 9.3M 8% /dev
tmpfs 3.9G 4.0K 3.9G 1% /dev/shm
/dev/mapper/pve-data 33G 8.5G 25G 26% /var/lib/vz
/dev/sda1 504M 46M 433M 10% /boot
/dev/mapper/srv2008_os-os
247G 230G 4.5G 99% /mnt/srv2008_os
/dev/mapper/srv2008_store-store
247G 44G 191G 19% /mnt/srv2008_store
192.168.20.28:/c/backup
926G 183G 744G 20% /mnt/pve/backup

 

[dietmar]

I have not enabled the write cache on the controller due to possible unsecurities of data loss by power losses.

You need a battery for the RAID controller (BBU).

 

[alexpacio]

So, you are saying that i will not get the expected performances if i will not buy and install a BBU?

 

[dietmar]

So, you are saying that i will not get the expected performances if i will not buy and install a BBU?

No, what you get is the expected performance (without BBU).

If you want better performance, you need a BBU (so that you can enable the cache).

 

[jaimito]

See http://forum.proxmox.com/threads/45...oLiant-DL385-G7-12-core?highlight=performance for a similar issue; and the resolution (a battery!)