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AmosSam
n00b
Joined: 30 Jul 2006
Posts: 7
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 Posted: Sun Jul 30, 2006 6:19 pm Post subject: SCSI disk low performance ? [SOLVED] |
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Hello
I've googled and searched on this forum, and on gentoo-wiki, but I can't find solution for my "problem".
Problem is this:
I have dual Xeon 2.4Ghz with HyperThreading enabled (in BIOS and kernel), Adaptec AIC-7892A U160/m (rev 02) scsi controler,
1.5 Gb Ram, GeForce 6600, and Tyan Tiger mainboard with ICH4 chipset.
Disk configuration folows:
(folowing info is taken from dmesg)
/dev/sda (36 Gb)
| Code: |
Vendor: MAXTOR Model: ATLAS10K4_36WLS Rev: DFQ1
Type: Direct-Access ANSI SCSI revision: 03
scsi0:A:0:0: Tagged Queuing enabled. Depth 32
target0:0:0: Beginning Domain Validation
target0:0:0: wide asynchronous.
target0:0:0: FAST-20 WIDE SCSI 40.0 MB/s ST (50 ns, offset 127)
target0:0:0: Domain Validation skipping write tests
target0:0:0: Ending Domain Validation
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/dev/sdb (9Gb)
| Code: |
Vendor: IBM Model: DDRS-39130W Rev: S71D
Type: Direct-Access ANSI SCSI revision: 02
scsi0:A:8:0: Tagged Queuing enabled. Depth 32
target0:0:8: Beginning Domain Validation
target0:0:8: wide asynchronous.
target0:0:8: FAST-20 WIDE SCSI 40.0 MB/s ST (50 ns, offset 15)
target0:0:8: Domain Validation skipping write tests
target0:0:8: Ending Domain Validation
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/dev/hdc (40Gb)
| Code: |
hdc: Maxtor 6K040L0, ATA DISK drive
ide1 at 0x170-0x177,0x376 on irq 15
hdc: max request size: 128KiB
hdc: 80293248 sectors (41110 MB) w/2048KiB Cache, CHS=65535/16/63, UDMA(100)
hdc: cache flushes supported
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And the problem is this. The folowing lines is what hdparm gives:
| Code: |
xeon / # hdparm -tT /dev/sda /dev/sdb /dev/hdc
/dev/sda:
Timing cached reads: 1164 MB in 2.00 seconds = 581.96 MB/sec
Timing buffered disk reads: 96 MB in 3.00 seconds = 32.00 MB/sec
/dev/sdb:
Timing cached reads: 1164 MB in 2.00 seconds = 580.80 MB/sec
Timing buffered disk reads: 40 MB in 3.15 seconds = 12.69 MB/sec
/dev/hdc:
Timing cached reads: 1172 MB in 2.00 seconds = 584.79 MB/sec
Timing buffered disk reads: 174 MB in 3.02 seconds = 57.54 MB/sec
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I'm mising something or the ATA disk si faster then SCSI disk?
Do I have to mention that both disk are 10K rpm? And yes, 9 Gb disk is litle older, but Maxtor isn't!!
In kernel I included correct scsi driver.
What can I do do get some better performance from SCSI disks?
this is result of 'uname -a'
| Code: |
Linux xeon 2.6.15-gentoo-r1 #3 SMP PREEMPT Sun Apr 23 20:43:16 CEST 2006 i686 Intel(R) XEON(TM) CPU 2.40GHz GenuineIntel GNU/Linux
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Thanks in advance for any help!!
_________________
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That's all from Amos Sam
Last edited by AmosSam on Mon Jul 31, 2006 6:37 pm; edited 1 time in total |
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piavlo
Tux's lil' helper
Joined: 21 Jun 2005
Posts: 141
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| Posted: Mon Jul 31, 2006 12:25 am Post subject: |
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You are using the defaults of your adaptec card which is 40ms/s
| Code: | | target0:0:0: FAST-20 WIDE SCSI 40.0 MB/s ST |
while it should be | Code: | | arget0:0:0: FAST-80 WIDE SCSI 160.0 MB/s DT |
You should change the speed in adaptec utility then system is booting to max 160mb/s
then in dmesg will be like this | Code: | ACPI: PCI Interrupt 0000:05:01.0[A] -> GSI 22 (level, low) -> IRQ 17
scsi0 : Adaptec AIC7XXX EISA/VLB/PCI SCSI HBA DRIVER, Rev 7.0
<Adaptec 29160N Ultra160 SCSI adapter>
aic7892: Ultra160 Wide Channel A, SCSI Id=7, 32/253 SCBs
Vendor: IBM Model: DDYS-T36950N Rev: S93E
Type: Direct-Access ANSI SCSI revision: 03
scsi0:A:0:0: Tagged Queuing enabled. Depth 32
target0:0:0: Beginning Domain Validation
target0:0:0: wide asynchronous.
target0:0:0: FAST-80 WIDE SCSI 160.0 MB/s DT (12.5 ns, offset 63)
target0:0:0: Ending Domain Validation
Vendor: IBM Model: DDYS-T36950N Rev: S93E
Type: Direct-Access ANSI SCSI revision: 03 |
Then you can end up with max speed of 80mb/s for reach of the 2 drives 80+80=160, but probably 60mb/s with the faster sda drive and even less with sdb. |
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AmosSam
n00b
Joined: 30 Jul 2006
Posts: 7
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| Posted: Mon Jul 31, 2006 6:39 pm Post subject: |
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It was already on 160m/b, but it seems that older disk was slowing down (they where on the same channel) so I removed it.
Thanks anyway
[/code]
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