> > I wander if the SATA feature of NCQ would speed the disk I/O up but
> > there is likely no easy way to upgrade CentOS 4.x to do that.
>
> AFAICT CentOS 4.5 kernel was originally based on 2.6.9. A long time
> has passed since then and the 2.6.21/2.6.22 kernels where the new
> libata based disk subsystem (starting with the nice features you are
> looking for) was first included in the kernel.
>
> The upgrade should still be doable (depending on your skills).
>
> The most significant change you might experience is the new udev
> device structure which replaced devfs at around ~2.6.12 IIRC.
> Anyway. I'd give it a shot if you have some minutes of downtime.
> Well, if you update... go to the latest stable tree.
This is what I show.
Linux version 2.6.9-67.0.4.ELsmp (mockbuild@???) (gcc
version 3.4.6 20060404 (Red Hat 3.4.6-9)) #1 SMP Sun Feb 3 07:08:57
EST 2008
Also,
libata version 2.00 loaded.
sata_nv 0000:00:0e.0: version 3.2
ACPI: PCI Interrupt 0000:00:0e.0[A] -> GSI 20 (level, low) -> IRQ 201
PCI: Setting latency timer of device 0000:00:0e.0 to 64
ata1: SATA max UDMA/133 cmd 0x9F0 ctl 0xBF2 bmdma 0xE000 irq 201
ata2: SATA max UDMA/133 cmd 0x970 ctl 0xB72 bmdma 0xE008 irq 201
scsi0 : sata_nv
ata1: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata1.00: ATA-7, max UDMA/133, 976773168 sectors: LBA48 NCQ (depth 0/32)
ata1.00: ata1: dev 0 multi count 1
ata1.00: configured for UDMA/133
scsi1 : sata_nv
ata2: SATA link up 3.0 Gbps (SStatus 123 SControl 300)
ata2.00: ATA-8, max UDMA7, 781422768 sectors: LBA48 NCQ (depth 0/32)
ata2.00: ata2: dev 0 multi count 1
ata2.00: configured for UDMA/133
Using cfq io scheduler
Vendor: ATA Model: ST3500630AS Rev: 3.AA
Type: Direct-Access ANSI SCSI revision: 05
SCSI device sda: 976773168 512-byte hdwr sectors (500108 MB)
SCSI device sda: drive cache: write back
SCSI device sda: 976773168 512-byte hdwr sectors (500108 MB)
SCSI device sda: drive cache: write back
sda: sda1 sda2
Attached scsi disk sda at scsi0, channel 0, id 0, lun 0
Vendor: ATA Model: SAMSUNG HD403LJ Rev: CT10
Type: Direct-Access ANSI SCSI revision: 05
SCSI device sdb: 781422768 512-byte hdwr sectors (400088 MB)
SCSI device sdb: drive cache: write back
SCSI device sdb: 781422768 512-byte hdwr sectors (400088 MB)
SCSI device sdb: drive cache: write back
sdb: sdb1
Matt