Write performance

[cloudtech]

Hello,

I have two Open-E SANs for OnApp Cloud and they are using Multipath with Failover. From a VM, I use dd command to test the write performance, the speed is between 70MB/s to 140MB/s. I expect it could be more, but not sure how much. Is the current write speed normal or underperformed? Thank you for any advice.

Spec:

RAID/SCSI controllers
LSI Logic / Symbios Logic LSI MegaSAS 9260 (rev 05)

Network controllers
Intel Corporation 82599EB 10-Gigabit SFI/SFP+ Network Connection (rev 01)
Intel Corporation 82599EB 10-Gigabit SFI/SFP+ Network Connection (rev 01)


Hardware RAID info:
Attribute name Value
State: Optimal
Strip size: 64kB
Raid Level: RAID6
Number of disk in one array: 8
Size: 11438364MB
Default Write Policy: Write Back
Read Policy: Readahead
Access Policy: Read-Write
Cache Policy: Cached
Disk cache: Disk's Default

Disk info:
ATA WDC WD2003FYYS-01D01 WD-WMAY02821178

My Test results:


1. VM (1 cores / 20% CPU share / 1 GB RAM), CentOS 5.6, x86

Test 1(1.2G):
[root@cloud1vm1 ~]# dd if=/dev/zero of=/var/tmpMnt bs=1024 count=1200000
1200000+0 records in
1200000+0 records out
1228800000 bytes (1.2 GB) copied, 8.67519 seconds, 142 MB/s

Test 2(12G):
[root@cloud1vm1 ~]# dd if=/dev/zero of=/var/tmpMnt bs=1024 count=12000000
12000000+0 records in
12000000+0 records out
12288000000 bytes (12 GB) copied, 161.35 seconds, 76.2 MB/s

[root@cloud1vm1 ~]# hdparm -Tt /dev/sda1

/dev/sda1:
Timing cached reads: 23868 MB in 1.99 seconds = 11992.40 MB/sec
Timing buffered disk reads: 302 MB in 3.01 seconds = 100.19 MB/sec

2. VM (4 cores / 100% CPU share / 4 GB RAM), CentOS 5.6, x86

Test 1(1.2G):
[root@cloud1vm1 ~]# dd if=/dev/zero of=/var/tmpMnt bs=1024 count=1200000
1200000+0 records in
1200000+0 records out
1228800000 bytes (1.2 GB) copied, 8.8775 seconds, 138 MB/s

Test 2(12G):
[root@cloud1vm1 ~]# dd if=/dev/zero of=/var/tmpMnt bs=1024 count=12000000
12000000+0 records in
12000000+0 records out
12288000000 bytes (12 GB) copied, 143.073 seconds, 85.9 MB/s

[root@cloud1vm1 ~]# hdparm -Tt /dev/sda1

/dev/sda1:
Timing cached reads: 27832 MB in 1.99 seconds = 13975.05 MB/sec
Timing buffered disk reads: 306 MB in 3.01 seconds = 101.69 MB/sec

[Gr-R]

I have sent you some performance recommendations via your support case.

[cloudtech]

I had made the adjustments, the write performance is a little better. But the overall speed is still in 100MB level. Could you tell a range of the write speed base on my hardware? Like 300MB to 500MB/s? Thanks.