[rescue] playing with the new E250 ... disk performance vs. old PeeCee
magnus at yonderway.com
Mon Dec 18 13:26:08 CST 2006
Joshua Boyd wrote:
> I don't recall what you said your drives were, but they are probably U2W
> (80MB/s bus speed) or U160 (160MB/s bus speed). However, you also
> should look at the actual drive speed. For instance, if you have two
> U320 drives that only do 50MB/s each, then you loose nothing by putting
> them on a U160 controller, or putting them on seperate channels of a U2W
I am going to shut down the box and pull a drive when I get home.
Here is how Linux describes it in /proc/scsi/scsi:
Host: scsi0 Channel: 00 Id: 00 Lun: 00
Vendor: IBM-ESXS Model: DTN073C3UCDY10FN Rev: S27P
Type: Direct-Access ANSI SCSI revision: 03
Here is the relevant section of dmesg:
[ 15.162202] SCSI subsystem initialized
[ 15.180035] sym0: <875> rev 0x14 at pci 0001:00:03.0 irq 5,7e0
[ 15.266758] sym0: No NVRAM, ID 7, Fast-20, SE, parity checking
[ 15.273964] sym0: SCSI BUS has been reset.
[ 15.273994] scsi0 : sym-2.2.2
[ 1.093291] Vendor: IBM-ESXS Model: DTN073C3UCDY10FN Rev: S27P
[ 1.093350] Type: Direct-Access ANSI SCSI
[ 1.093400] target0:0:0: tagged command queuing enabled, command
queue depth 16.
[ 1.093460] target0:0:0: Beginning Domain Validation
[ 1.093665] target0:0:0: asynchronous.
[ 1.094890] target0:0:0: FAST-20 SCSI 20.0 MB/s ST (50 ns, offset 16)
[ 1.095635] target0:0:0: Domain Validation skipping write tests
[ 1.095654] target0:0:0: Ending Domain Validation
[ 2.556808] Vendor: TOSHIBA Model: DVD-ROM SD-M1401 Rev: 1007
[ 2.556861] Type: CD-ROM ANSI SCSI
[ 2.556909] target0:0:6: Beginning Domain Validation
[ 2.557250] target0:0:6: asynchronous.
[ 2.567982] target0:0:6: FAST-20 SCSI 20.0 MB/s ST (50 ns, offset 16)
[ 2.575804] target0:0:6: Domain Validation skipping write tests
[ 2.575821] target0:0:6: Ending Domain Validation
[ 4.911977] sym1: <875> rev 0x14 at pci 0001:00:03.1 irq 5,7e6
[ 4.999636] sym1: No NVRAM, ID 7, Fast-20, SE, parity checking
[ 5.006940] sym1: SCSI BUS has been reset.
[ 5.006974] scsi1 : sym-2.2.2
[ 12.480822] Driver 'sd' needs updating - please use bus_type methods
[ 12.482278] SCSI device sda: 143374000 512-byte hdwr sectors (73407 MB)
[ 12.483398] SCSI device sda: drive cache: write through
[ 12.484265] SCSI device sda: 143374000 512-byte hdwr sectors (73407 MB)
[ 12.485410] SCSI device sda: drive cache: write through
[ 12.485428] sda: sda1 sda2 sda3
[ 12.492904] sd 0:0:0:0: Attached scsi disk sda
[ 13.018272] device-mapper: 4.4.0-ioctl (2005-01-12) initialised:
dm-devel at redhat.com
[ 13.327550] kjournald starting. Commit interval 5 seconds
[ 13.327603] EXT3-fs: mounted filesystem with ordered data mode.
[ 2.192084] sr0: scsi3-mmc drive: 40x/40x cd/rw xa/form2 cdda tray
[ 2.192120] Uniform CD-ROM driver Revision: 3.20
[ 2.192307] sr 0:0:6:0: Attached scsi CD-ROM sr0
[ 2.243674] sd 0:0:0:0: Attached scsi generic sg0 type 0
[ 2.243767] sr 0:0:6:0: Attached scsi generic sg1 type 5
The really key thing I am seeing there is that Linux is seeing a
20MB/sec SCSI device. So if the controller (and certainly the disk) are
good for 40MB/sec as you suggest, then there may be software issues.
The chipset is being detected as sym53c875. From what I can tell from
some googling, that chipset should indeed be capable of going 40MB/sec.
Something here is amiss.
More information about the rescue