Re: md RAID over SATA performance

["J.A. Magallon" <jamagallon@able.es>]

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