• Status: Solved
  • Priority: Medium
  • Security: Public
  • Views: 772
  • Last Modified:

Slow Speed Tests - Perc6i + 8 x 1.5TB RAID 10

Hey guys

Got a a Dual Quad Core 32GB Server
Perc6i with BBU
8 x 1.5TB WD RE4 RAID 10
Filesystem: EXT4
Strip: 64K

Its running slow or these commands are wrong, any help would be appreciated

root@svr1:~# hdparm -Tt /dev/sdb1

 Timing cached reads:   14932 MB in  2.00 seconds = 7473.84 MB/sec
 Timing buffered disk reads: 682 MB in  3.00 seconds = 227.30 MB/sec
root@svr1:~# hdparm -tT /dev/sdb1

root@svr1:~# dd if=/dev/sdb1 of=test bs=64k count=16k conv=fdatasync
16384+0 records in
16384+0 records out
1073741824 bytes (1.1 GB) copied, 14.9253 s, 71.9 MB/s
Jared Hirst
Jared Hirst
2 Solutions
andyalderSaggar makers bottom knockerCommented:
Looks reasonable to me for 7.2K disks.

227MB/s 64K blocksize = 3632 IOPS (far better than expected but it's sequential data so that's believable)

71MB/s 64K blocksize 1136 IOPS, again better than expected but again sequential data. Much worse than the previous but there again of=test is probably on the same disks so you're reading from the same thing you're writing to which makes for a lot more head movement.

What figures were you expecting?
YOur performance will "double" if you use the bitbucket as source of the data instead of existing drives, i.e, use if=/dev/zero  
As Andyalder posted, the numbers you got are quite reasonable.   SATA disks and performance are somewhat mutually exclusive.
Jared HirstCEOAuthor Commented:
Thanks guys totally forgot what I was testing here did think about block size of the writes :)

Featured Post


Modern healthcare requires a modern cloud. View this brief video to understand how the Concerto Cloud for Healthcare can help your organization.

Tackle projects and never again get stuck behind a technical roadblock.
Join Now