Andrey Andreev wrote:
Hi,
I upgraded my 2.6.6 kernel to 2.6.8 (the fedora update). I run a SATA drive on a Sil 3112A controller. I quickly noticed that the SATA drive was no longer visible under /dev/hde, but under /dev/sda, fixed my fstab, etc.
However, as Sil 3112 has had very varied performance with different kernels, and there obviously was a change in the way it worked, I ran:
[andrei@brie andrei]$ sudo /sbin/hdparm -t -T /dev/sda /dev/sda: Timing buffer-cache reads: 1564 MB in 2.00 seconds = 780.95 MB/sec Timing buffered disk reads: 44 MB in 3.12 seconds = 14.11 MB/sec
I have not seen this slowdown:
[root@quicksilver home]# uname -r 2.6.8-1.521 [root@quicksilver home]# sbin/hdparm -t -T /dev/sda Timing buffer-cache reads: 1524 MB in 2.00 seconds = 761.73 MB/sec Timing buffered disk reads: 132 MB in 3.01 seconds = 43.85 MB/sec
Which is pretty awfuly slow, compared to 2.6.6 (over 50 MB/sec). Otherwise, I can spot no other errors or problems with it.
Any pointers as to what I should change? Is this a common result with that controller?
See the relevant dmesg part
8<--------------------------------------->8
SCSI subsystem initialized
libata version 1.02 loaded.
sata_sil version 0.54
ACPI: PCI interrupt 0000:01:0c.0[A] -> GSI 11 (level, low) -> IRQ 11
ata1: SATA max UDMA/100 cmd 0x2285D080 ctl 0x2285D08A bmdma 0x2285D000 irq 11
ata2: SATA max UDMA/100 cmd 0x2285D0C0 ctl 0x2285D0CA bmdma 0x2285D008 irq 11
ata1: dev 0 cfg 49:2f00 82:346b 83:7d01 84:4003 85:3469 86:3c01 87:4003 88:207f
ata1: dev 0 ATA, max UDMA/133, 312581808 sectors: lba48
ata1(0): applying Seagate errata fix
ata1: dev 0 configured for UDMA/100
scsi0 : sata_sil
ata2: no device found (phy stat 00000000)
scsi1 : sata_sil
Vendor: ATA Model: ST3160023AS Rev: 3.18
Type: Direct-Access ANSI SCSI revision: 05
Mine looks like:
libata version 1.02 loaded.
sata_sil version 0.54
ACPI: PCI interrupt 0000:01:0d.0[A] -> GSI 11 (level, low) -> IRQ 11
ata1: SATA max UDMA/100 cmd 0x4285D080 ctl 0x4285D08A bmdma 0x4285D000 irq 11
ata2: SATA max UDMA/100 cmd 0x4285D0C0 ctl 0x4285D0CA bmdma 0x4285D008 irq 11
ata1: dev 0 cfg 49:2f00 82:346b 83:7f21 84:4003 85:3469 86:3c01 87:4003 88:203f
ata1: dev 0 ATA, max UDMA/100, 234441648 sectors: lba48
ata1: dev 0 configured for UDMA/100
scsi0 : sata_sil
ata2: no device found (phy stat 00000000)
scsi1 : sata_sil
Vendor: ATA Model: WDC WD1200JD-00G Rev: 02.0
Type: Direct-Access ANSI SCSI revision: 05
so, it looks like the big difference is the drive itself. Yours is a Seagate, and mine is a Western Digital.
Also, from the man pages of hdparm, for the -t and the -T options:
For meaningful results, this operation should be
repeated 2-3 times on an otherwise inactive system (no other
active processes) with at least a couple of megabytes of free
memory.
