[SOLVED] ext3 pveperf bad fsync/sec?

S

Stroker89

New Member
Sep 26, 2013
9
0
1
Hi,

i have a server with 2 x 2TB SW-Raid 1.
Im using Proxmox since version 3.0.
With version 3.x the fsync/sec with pveperf was around 800/sec

Since i installed version 4 the fsync/sec dropped dramatically :(
The load of the server is very low...

pveperf:
Code: 
CPU BOGOMIPS:      54395.92
REGEX/SECOND:      2935422
HD SIZE:           19.56 GB (/dev/dm-0)
BUFFERED READS:    156.46 MB/sec
AVERAGE SEEK TIME: 7.10 ms
FSYNCS/SECOND:     31.93
DNS EXT:           92.45 ms
DNS INT:           14.25 ms

Version:
Code: 
proxmox-ve: 4.1-34 (running kernel: 4.2.6-1-pve)
pve-manager: 4.1-13 (running version: 4.1-13/cfb599fb)
pve-kernel-4.2.6-1-pve: 4.2.6-36
lvm2: 2.02.116-pve2
corosync-pve: 2.3.5-2
libqb0: 1.0-1
pve-cluster: 4.0-32
qemu-server: 4.0-55
pve-firmware: 1.1-7
libpve-common-perl: 4.0-48
libpve-access-control: 4.0-11
libpve-storage-perl: 4.0-40
pve-libspice-server1: 0.12.5-2
vncterm: 1.2-1
pve-qemu-kvm: 2.5-5
pve-container: 1.0-44
pve-firewall: 2.0-17
pve-ha-manager: 1.0-21
ksm-control-daemon: 1.2-1
glusterfs-client: 3.5.2-2+deb8u1
lxc-pve: 1.1.5-7
lxcfs: 0.13-pve3
cgmanager: 0.39-pve1
criu: 1.6.0-1
fence-agents-pve: not correctly installed
openvswitch-switch: 2.3.2-2

Mounts /etc/fstab:
Code: 
proc /proc proc defaults 0 0
/dev/md/0 none swap sw 0 0
/dev/md/1 /boot ext3 defaults 0 0
# /dev/md/2 belongs to LVM volume group 'system'
# /dev/md/3 belongs to LVM volume group 'images'
# /dev/md/4 belongs to LVM volume group 'storage'
# /dev/md/5 belongs to LVM volume group 'backup'
/dev/system/root  /  ext3  defaults 0 0
/dev/system/tmp  /tmp  ext3  defaults 0 0
/dev/system/var  /var  ext3  defaults 0 0
/dev/images/vmimages     /vmimages      ext3    defaults        0       0
/dev/backup/vmbackups   /vmbackup       ext3    defaults        0       0

The Raid isnt rebuilding or anything like that...
Any idea why the fsync/sec are so low?

Thanks.
 
sw raid isn't really for running vms on it. Performance always was not that good.

Maybe in pve3 the filesystem was mounted with no sync option?
 
Thanks dietmar.
Could i use barrier=0 in the new version two?
Is there anything to observe with barrier=0?
 
Ok my /etc/fstab looks now like this
Code: 
proc /proc proc defaults 0 0
/dev/md/0 none swap sw 0 0
/dev/md/1 /boot ext3 defaults,barrier=0 0 1
# /dev/md/2 belongs to LVM volume group 'system'
# /dev/md/3 belongs to LVM volume group 'images'
# /dev/md/4 belongs to LVM volume group 'storage'
# /dev/md/5 belongs to LVM volume group 'backup'
/dev/system/root  /  ext3  defaults,barrier=0 0 2
/dev/system/tmp  /tmp  ext3  defaults,barrier=0 0 0
/dev/system/var  /var  ext3  defaults,barrier=0 0 2
/dev/images/vmimages     /vmimages      ext3    defaults,barrier=0      0       0
/dev/backup/vmbackups   /vmbackup       ext3    defaults,barrier=0      0       0

and the fsync/sec performance is now:
Code: 
CPU BOGOMIPS:      54403.60
REGEX/SECOND:      3020933
HD SIZE:           19.56 GB (/dev/dm-0)
BUFFERED READS:    141.97 MB/sec
AVERAGE SEEK TIME: 7.30 ms
FSYNCS/SECOND:     1213.35
DNS EXT:           80.58 ms
DNS INT:           11.97 ms

Thanks for the tip.
 
You must log in or register to reply here.
Top Bottom