* Re: md RAID over SATA performance
2004-09-03 0:05 md RAID over SATA performance J.A. Magallon
@ 2004-09-03 0:47 ` J.A. Magallon
2004-09-03 8:09 ` David Greaves
2004-09-03 11:13 ` Alan Cox
` (3 subsequent siblings)
4 siblings, 1 reply; 10+ messages in thread
From: J.A. Magallon @ 2004-09-03 0:47 UTC (permalink / raw)
To: linux-kernel
On 2004.09.03, J.A. Magallon wrote:
> Hi all...
>
> I am buildin an array with a linux box, and I run 2.6.8.1 (not stock, but
> the mandrake cooker version).
>
> Disks are 6 SATA drives, plugged to a couple of Promise FastTrak S150 TX4
> cards.
>
> Problem is that i get really poor performance. A single drive gives about
> 57 Mb/s, and a raid1 with two just gives about 64 Mb/s (measured with
^^^^^
OOPS, I meant raid0...
> hdparm -tT). With the six drives:
>
> nada:~/soft/kernel# hdparm -tT /dev/sda
>
> /dev/sda:
> Timing buffer-cache reads: 844 MB in 2.01 seconds = 419.96 MB/sec
> Timing buffered disk reads: 174 MB in 3.01 seconds = 57.84 MB/sec
> nada:~/soft/kernel# hdparm -tT /dev/md0
>
> /dev/md0:
> Timing buffer-cache reads: 884 MB in 2.00 seconds = 441.63 MB/sec
> Timing buffered disk reads: 310 MB in 3.01 seconds = 103.07 MB/sec
>
> The real goal is to build a raid5 system, but I just tested with raid1.
>
> Any ideas/suggestions ?
>
> TIA
>
> More info:
>
> nada:~/soft/kernel# mdadm --detail /dev/md0
> /dev/md0:
> Version : 00.90.01
> Creation Time : Fri Sep 3 01:52:22 2004
> Raid Level : raid0
> Array Size : 1470669312 (1402.54 GiB 1505.97 GB)
> Raid Devices : 6
> Total Devices : 6
> Preferred Minor : 0
> Persistence : Superblock is persistent
>
> Update Time : Fri Sep 3 01:52:22 2004
> State : clean
> Active Devices : 6
> Working Devices : 6
> Failed Devices : 0
> Spare Devices : 0
>
> Chunk Size : 128K
>
> UUID : c7373f10:3d04436b:a7d2bbce:8317b56f
> Events : 0.14
>
> Number Major Minor RaidDevice State
> 0 8 1 0 active sync /dev/sda1
> 1 8 17 1 active sync /dev/sdb1
> 2 8 33 2 active sync /dev/sdc1
> 3 8 49 3 active sync /dev/sdd1
> 4 8 65 4 active sync /dev/sde1
> 5 8 81 5 active sync /dev/sdf1
>
> nada:~/soft/kernel# lspci
> 00:00.0 Host bridge: VIA Technologies, Inc. VT8633 [Apollo Pro266] (rev 01)
> 00:01.0 PCI bridge: VIA Technologies, Inc. VT8633 [Apollo Pro266 AGP]
> 00:07.0 RAID bus controller: Promise Technology, Inc. PDC20319 (FastTrak S150 TX4) (rev 02)
> 00:08.0 RAID bus controller: Promise Technology, Inc. PDC20319 (FastTrak S150 TX4) (rev 02)
> 00:0b.0 Multimedia audio controller: Ensoniq 5880 AudioPCI (rev 02)
> 00:0c.0 RAID bus controller: Promise Technology, Inc. PDC20267 (FastTrak100/Ultra100) (rev 02)
> 00:0d.0 Ethernet controller: Intel Corp. 82557/8/9 [Ethernet Pro 100] (rev 08)
> 00:11.0 ISA bridge: VIA Technologies, Inc. VT8233 PCI to ISA Bridge
> 00:11.1 IDE interface: VIA Technologies, Inc. VT82C586A/B/VT82C686/A/B/VT823x/A/C PIPC Bus Master IDE (rev 06)
> 00:11.2 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 1b)
> 00:11.3 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 1b)
> 00:11.4 USB Controller: VIA Technologies, Inc. VT82xxxxx UHCI USB 1.1 Controller (rev 1b)
> 00:12.0 Ethernet controller: VIA Technologies, Inc. VT6102 [Rhine-II] (rev 62)
> 01:00.0 VGA compatible controller: nVidia Corporation NV11 [GeForce2 MX/MX 400] (rev b2)
>
--
J.A. Magallon <jamagallon()able!es> \ Software is like sex:
werewolf!able!es \ It's better when it's free
Mandrakelinux release 10.1 (Beta 1) for i586
Linux 2.6.8.1-mm4 (gcc 3.4.1 (Mandrakelinux (Alpha 3.4.1-3mdk)) #8
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: md RAID over SATA performance
2004-09-03 0:47 ` J.A. Magallon
@ 2004-09-03 8:09 ` David Greaves
2004-09-03 16:15 ` Mark Lord
0 siblings, 1 reply; 10+ messages in thread
From: David Greaves @ 2004-09-03 8:09 UTC (permalink / raw)
To: J.A. Magallon; +Cc: linux-kernel
J.A. Magallon wrote:
>
> On 2004.09.03, J.A. Magallon wrote:
>
>> Hi all...
>>
>> I am buildin an array with a linux box, and I run 2.6.8.1 (not stock,
>> but
>> the mandrake cooker version).
>>
>> Problem is that i get really poor performance.
>
Try:
blockdev --getra /dev/sda1
blockdev --getra /dev/md0
and if needed:
blockdev --setra 4096 /dev/sda1
blockdev --setra 4096 /dev/md0
Also if you use lvm:
blockdev --setra 4096 /dev/video_vg/video_lv
as appropriate.
Tune as needed :)
David
^ permalink raw reply [flat|nested] 10+ messages in thread
* Re: md RAID over SATA performance
2004-09-03 0:05 md RAID over SATA performance J.A. Magallon
2004-09-03 0:47 ` J.A. Magallon
@ 2004-09-03 11:13 ` Alan Cox
2004-09-03 13:24 ` Brad Campbell
` (2 subsequent siblings)
4 siblings, 0 replies; 10+ messages in thread
From: Alan Cox @ 2004-09-03 11:13 UTC (permalink / raw)
To: J.A. Magallon; +Cc: Lista Linux-Kernel, Jeff Garzik
On Gwe, 2004-09-03 at 01:05, J.A. Magallon wrote:
> Problem is that i get really poor performance. A single drive gives about
> 57 Mb/s, and a raid1 with two just gives about 64 Mb/s (measured with
> hdparm -tT). With the six drives:
Looks about right. Whats your total PCI bus bandwidth, whats your VIA
V-Link bandwidth between the bridges ?
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: md RAID over SATA performance
2004-09-03 0:05 md RAID over SATA performance J.A. Magallon
2004-09-03 0:47 ` J.A. Magallon
2004-09-03 11:13 ` Alan Cox
@ 2004-09-03 13:24 ` Brad Campbell
2004-09-03 16:33 ` Mark Lord
2004-09-03 21:58 ` J.A. Magallon
4 siblings, 0 replies; 10+ messages in thread
From: Brad Campbell @ 2004-09-03 13:24 UTC (permalink / raw)
To: J.A. Magallon; +Cc: Lista Linux-Kernel, Jeff Garzik
J.A. Magallon wrote:
> Hi all...
>
> I am buildin an array with a linux box, and I run 2.6.8.1 (not stock, but
> the mandrake cooker version).
>
> Disks are 6 SATA drives, plugged to a couple of Promise FastTrak S150 TX4
> cards.
>
> Problem is that i get really poor performance. A single drive gives about
> 57 Mb/s, and a raid1 with two just gives about 64 Mb/s (measured with
> hdparm -tT). With the six drives:
>
> nada:~/soft/kernel# hdparm -tT /dev/sda
>
> /dev/sda:
> Timing buffer-cache reads: 844 MB in 2.01 seconds = 419.96 MB/sec
> Timing buffered disk reads: 174 MB in 3.01 seconds = 57.84 MB/sec
> nada:~/soft/kernel# hdparm -tT /dev/md0
>
> /dev/md0:
> Timing buffer-cache reads: 884 MB in 2.00 seconds = 441.63 MB/sec
> Timing buffered disk reads: 310 MB in 3.01 seconds = 103.07 MB/sec
>
> The real goal is to build a raid5 system, but I just tested with raid1.
>
Here are some real-world figures for you (Not that they mean anything!)
srv:/home/brad# hdparm -t -T /dev/md0
/dev/md0:
Timing buffer-cache reads: 1340 MB in 2.00 seconds = 668.76 MB/sec
BLKGETSIZE failed: File too large
Timing buffered disk reads: 182 MB in 3.02 seconds = 60.31 MB/sec
srv:/home/brad# df -h
Filesystem Size Used Avail Use% Mounted on
/dev/hda1 19G 11G 6.5G 64% /
tmpfs 252M 0 252M 0% /dev/shm
/dev/hda3 165G 21G 136G 13% /raid0
/dev/md0 2.1T 2.0T 114G 95% /raid
/dev/md2 459G 101G 358G 22% /raid2
srv:/home/brad# mdadm --detail /dev/md0
/dev/md0:
Version : 00.90.01
Creation Time : Sun May 2 18:02:14 2004
Raid Level : raid5
Array Size : 2206003968 (2103.81 GiB 2258.95 GB)
Device Size : 245111552 (233.76 GiB 250.99 GB)
Raid Devices : 10
Total Devices : 10
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Fri Sep 3 16:08:03 2004
State : clean, no-errors
Active Devices : 10
Working Devices : 10
Failed Devices : 0
Spare Devices : 0
Layout : left-asymmetric
Chunk Size : 128K
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/devfs/scsi/host0/bus0/target0/lun0/part1
1 8 17 1 active sync /dev/devfs/scsi/host1/bus0/target0/lun0/part1
2 8 33 2 active sync /dev/devfs/scsi/host2/bus0/target0/lun0/part1
3 8 49 3 active sync /dev/devfs/scsi/host3/bus0/target0/lun0/part1
4 8 65 4 active sync /dev/devfs/scsi/host4/bus0/target0/lun0/part1
5 8 81 5 active sync /dev/devfs/scsi/host5/bus0/target0/lun0/part1
6 8 97 6 active sync /dev/devfs/scsi/host6/bus0/target0/lun0/part1
7 8 113 7 active sync /dev/devfs/scsi/host7/bus0/target0/lun0/part1
8 8 129 8 active sync /dev/sdi1
9 8 145 9 active sync /dev/sdj1
UUID : 05cc3f43:de1ecfa4:83a51293:78015f1e
Events : 0.681631
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: md RAID over SATA performance
2004-09-03 0:05 md RAID over SATA performance J.A. Magallon
` (2 preceding siblings ...)
2004-09-03 13:24 ` Brad Campbell
@ 2004-09-03 16:33 ` Mark Lord
2004-09-03 20:27 ` Tomasz Torcz
2004-09-03 21:58 ` J.A. Magallon
4 siblings, 1 reply; 10+ messages in thread
From: Mark Lord @ 2004-09-03 16:33 UTC (permalink / raw)
To: J.A. Magallon; +Cc: Lista Linux-Kernel, Jeff Garzik
Even with hardware RAID the numbers I see are not often
much better than this.
Unless O_DIRECT is used (hdparm --direct), in which case they
immediately jump to a level that is more limited by the PCI
and memory speeds of the system.
Eg. 205Mbytes/sec for a 4-drive RAID0 over 64-bit/66Mhz PCI.
I guess the page_cache overhead is rather substantial
for the simple read-a-sequential-block test.
Cheers
--
Mark Lord
(hdparm keeper & the original "Linux IDE Guy")
^ permalink raw reply [flat|nested] 10+ messages in thread* Re: md RAID over SATA performance
2004-09-03 0:05 md RAID over SATA performance J.A. Magallon
` (3 preceding siblings ...)
2004-09-03 16:33 ` Mark Lord
@ 2004-09-03 21:58 ` J.A. Magallon
4 siblings, 0 replies; 10+ messages in thread
From: J.A. Magallon @ 2004-09-03 21:58 UTC (permalink / raw)
To: linux-kernel
On 2004.09.03, J.A. Magallon wrote:
> Hi all...
>
> I am buildin an array with a linux box, and I run 2.6.8.1 (not stock, but
> the mandrake cooker version).
>
> Disks are 6 SATA drives, plugged to a couple of Promise FastTrak S150 TX4
> cards.
>
> Problem is that i get really poor performance. A single drive gives about
> 57 Mb/s, and a raid1 with two just gives about 64 Mb/s (measured with
> hdparm -tT). With the six drives:
>
>
Thanks to everybody for its answers...
My confusion/problem was that I has always tried with only two drives,
and with more or less old drives that gave around 20-25Mb/s each, so
the raid worked very optimally at about 50 Mb/s.
But with modern drives at 55 Mb/s, I hit the PCI speed limits, I suppose.
Board is a Supermicro P3TDDE, Via ApolloPro 266T chipset (aghhh),
33 MHz PCI, 2xPIII@933.
With a stock 2.6.8.1, I get this:
nada:~# hdparm -tT /dev/md0
/dev/md0:
Timing buffer-cache reads: 864 MB in 2.00 seconds = 431.63 MB/sec
Timing buffered disk reads: 252 MB in 3.01 seconds = 83.85 MB/sec
with this setup:
nada:~# mdadm --detail /dev/md0
/dev/md0:
Version : 00.90.01
Creation Time : Fri Sep 3 02:17:28 2004
Raid Level : raid5
Array Size : 1225557760 (1168.78 GiB 1254.97 GB)
Device Size : 245111552 (233.76 GiB 250.99 GB)
Raid Devices : 6
Total Devices : 6
Preferred Minor : 0
Persistence : Superblock is persistent
Update Time : Fri Sep 3 19:01:39 2004
State : clean
Active Devices : 6
Working Devices : 6
Failed Devices : 0
Spare Devices : 0
Layout : left-symmetric
Chunk Size : 256K
UUID : fd6fcad0:21da140b:072a82b1:11b3db21
Events : 0.239
Number Major Minor RaidDevice State
0 8 1 0 active sync /dev/sda1
1 8 17 1 active sync /dev/sdb1
2 8 33 2 active sync /dev/sdc1
3 8 49 3 active sync /dev/sdd1
4 8 65 4 active sync /dev/sde1
5 8 81 5 active sync /dev/sdf1
--
J.A. Magallon <jamagallon()able!es> \ Software is like sex:
werewolf!able!es \ It's better when it's free
Mandrakelinux release 10.1 (RC 1) for i586
Linux 2.6.8.1-mm4 (gcc 3.4.1 (Mandrakelinux (Alpha 3.4.1-3mdk)) #8
^ permalink raw reply [flat|nested] 10+ messages in thread