software raid + lvm and io performance

[maur]

Hi,

I have added vps on new machine with disk virtio placed at lvm. And changed io scheduler to deadline on main host and on vps.

hdparm -tT /dev/md2 (part of the lvm for vpses) on my main host returns: Timing buffered disk reads: ... 168.75MB/sec

vps hdparm -tT /dev/mapper...-root: 93.74 MB/sec

What else I can do to make this difference a bit.. smaller?

[edited]
Added bonnie++ test:

bonnie++ -n 0 -u 0 -r `free -m | grep 'Mem:' | awk '{print $2}'` -s $(echo "scale=0;`free -m | grep 'Mem:' | awk '{print $2}'`*2" | bc -l) -f -b -d /var
Using uid:0, gid:0.
Writing intelligently...done
Rewriting...done
Reading intelligently...done
start 'em...done...done...done...done...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
redinn 7932M 163856 16 79566 7 200926 8 128.6 2
Latency 422ms 1702ms 60534us 567ms


1.96,1.96,redinn,1,1335344862,7932M,,,,163856,16,79566,7,,,200926,8,128.6,2,,,,,,,,,,,,,,,,,,,422ms,1702ms,,60534us,567ms,,,,,,

 

[FinnTux]

Try 'blockio --setra 8192 /dev/vda' in the guest. Replace /dev/vda with correct disk of course.

 

[marotori]

I would suggest CFQ scheduler on the host... And either noop or deadline in the guest.


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[maur]

I'm migrating now 200GB there, after that I will check your suggestions and post the results, thanks for hints!