Greetings,
I'm attempting to benchmark software RAID5 on a system with:
- Promise SATAII150 TX4 card
- 4 Segate ST3300831AS drives
- custom built kernel 2.6.11 (to get driver for promise SATAIITX4)
- FC3 install
- EPIA M10000 mainboard, 256MB memory
The tools I'm familiar with for benchmarking a PATA based RAID system are:
- hdparm
- dd
Here are some interesting stats from my system:
[root@epiam10k ~]# more /proc/mdstat
Personalities : [raid5]
md0 : active raid5 sdd1[3] sdc1[2] sdb1[1] sda1[0]
879100608 blocks level 5, 4k chunk, algorithm 2 [4/4] [UUUU]
unused devices: <none>
[root@epiam10k ~]# hdparm -t /dev/sda
/dev/sda:
Timing buffered disk reads: 116 MB in 3.02 seconds = 38.45 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for
device
[root@epiam10k ~]# hdparm -t /dev/sda1
/dev/sda1:
Timing buffered disk reads: 104 MB in 3.05 seconds = 34.10 MB/sec
HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for
device
[root@epiam10k ~]# hdparm -t /dev/md0
/dev/md0:
Timing buffered disk reads: 72 MB in 3.03 seconds = 23.79 MB/sec
[root@epiam10k ~]# vmstat
procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
r b swpd free buff cache si so bi bo in cs us sy id wa
1 0 0 3628 8984 142704 0 0 423 23 1023 112 30 3 61 6
Observations:
- the performance of a raw SATA device (/dev/sda in the above example) seems
low when I compare it to a PATA drive from a previous system (which would get
about 45MB/sec)
- the performance of the RAID5 array (/dev/md0) seems very low - I expect
quite an increase over a single device due to striping
- the number of interrupts per second (1023) seems very high
Questions:
- is hdparm the right tool for looking at SATA devices?
- is the error regarding the ioctl an issue?
- how do I set/get the DMA modes for the SATA controller and SATA drives?
- why would the interrupts per sec reported from vmstat be so high?
Thanks for any suggesitons. Please 'cc' me in any replies to the list.
Tim Harvey
On 03.31, Tim Harvey wrote:
> Greetings,
>
> I'm attempting to benchmark software RAID5 on a system with:
> - Promise SATAII150 TX4 card
> - 4 Segate ST3300831AS drives
> - custom built kernel 2.6.11 (to get driver for promise SATAIITX4)
> - FC3 install
> - EPIA M10000 mainboard, 256MB memory
>
> The tools I'm familiar with for benchmarking a PATA based RAID system are:
> - hdparm
> - dd
>
> Here are some interesting stats from my system:
>
Here goes my setup/results, FWIW...
Hard: Dual PIII@9333
2 Promise FastTrak S150 TX4 (rev 02)
6x Maxtor 7Y250M0, 250Gb, 3 on each card.
Soft:
> [root@epiam10k ~]# more /proc/mdstat
> Personalities : [raid5]
> md0 : active raid5 sdd1[3] sdc1[2] sdb1[1] sda1[0]
> 879100608 blocks level 5, 4k chunk, algorithm 2 [4/4] [UUUU]
>
> unused devices: <none>
nada:~# cat /proc/mdstat
Personalities : [linear] [raid0] [raid1] [raid5] [multipath] [raid6] [raid10]
md0 : active raid5 sdf1[5] sde1[4] sdd1[3] sdc1[2] sdb1[1] sda1[0]
1225557760 blocks level 5, 256k chunk, algorithm 2 [6/6] [UUUUUU]
unused devices: <none>
> [root@epiam10k ~]# hdparm -t /dev/sda
>
> /dev/sda:
> Timing buffered disk reads: 116 MB in 3.02 seconds = 38.45 MB/sec
> HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for
> device
> [root@epiam10k ~]# hdparm -t /dev/sda1
>
> /dev/sda1:
> Timing buffered disk reads: 104 MB in 3.05 seconds = 34.10 MB/sec
> HDIO_DRIVE_CMD(null) (wait for flush complete) failed: Inappropriate ioctl for
> device
nada:~# hdparm -tT /dev/sda
/dev/sda:
Timing cached reads: 900 MB in 2.00 seconds = 449.84 MB/sec
Timing buffered disk reads: 172 MB in 3.03 seconds = 56.70 MB/sec
> [root@epiam10k ~]# hdparm -t /dev/md0
>
> /dev/md0:
> Timing buffered disk reads: 72 MB in 3.03 seconds = 23.79 MB/sec
>
nada:~# hdparm -tT /dev/md0
/dev/md0:
Timing cached reads: 912 MB in 2.01 seconds = 454.48 MB/sec
Timing buffered disk reads: 178 MB in 3.04 seconds = 58.60 MB/sec
> [root@epiam10k ~]# vmstat
> procs -----------memory---------- ---swap-- -----io---- --system-- ----cpu----
> r b swpd free buff cache si so bi bo in cs us sy id wa
> 1 0 0 3628 8984 142704 0 0 423 23 1023 112 30 3 61 6
>
> Observations:
> - the performance of a raw SATA device (/dev/sda in the above example) seems
> low when I compare it to a PATA drive from a previous system (which would get
> about 45MB/sec)
> - the performance of the RAID5 array (/dev/md0) seems very low - I expect
> quite an increase over a single device due to striping
> - the number of interrupts per second (1023) seems very high
>
It is not marvelous in my case, but slightly better than yours...
--
J.A. Magallon <jamagallon()able!es> \ Software is like sex:
werewolf!able!es \ It's better when it's free
Mandrakelinux release 10.2 (Cooker) for i586
Linux 2.6.11-jam10 (gcc 3.4.3 (Mandrakelinux 10.2 3.4.3-7mdk)) #1
On Wed, 2005-03-30 at 19:12 -0800, Tim Harvey wrote:
> - the number of interrupts per second (1023) seems very high
Why? You have 1000 timer interrupts every second, plus 23 from other
sources.
Lee