Topic: IDE RAID oddities

[Robert L.Baer]

Hi all,

I'm running a SME Server V5.6u Update4 and have a couple of questions regarding IDE RAID.

There are two identical harddisks, both as master on IDE1 and IDE2 respectivlly.  IDE2 has a CD-ROM drive, connected as slave.

The drives were brandnew when SME Server was installed, yet they show different drive geometry. Below is the output of  fdisk -l plus the relevant section of dmesg.

Does anyone know what the story is? Does this lead to problems? Is there any need to fix it and if so, how? The same thing  I experienced on another machine with different drives (60 GB, also WD), yet a third one with SCSI drives shows identical  heads, cylinders and sectors.

Could someone please enlighten me?
Thanks in advance,

Robert
 


fdisk -l /dev/hda

Disk /dev/hda: 255 heads, 63 sectors, 4865 cylinders
Units = cylinders of 16065 * 512 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/hda1   *         1        13    104391   fd  Linux raid autodetect
/dev/hda2            14      4832  38708617+  fd  Linux raid autodetect
/dev/hda3          4833      4865    265072+  fd  Linux raid autodetect


fdisk -l /dev/hdc

Disk /dev/hdc: 16 heads, 63 sectors, 77545 cylinders
Units = cylinders of 1008 * 512 bytes

   Device Boot    Start       End    Blocks   Id  System
/dev/hdc1   *         1       203    102280+  fd  Linux raid autodetect
/dev/hdc2           204     77024  38717784   fd  Linux raid autodetect
/dev/hdc3         77025     77544    262080   fd  Linux raid autodetect




ide: Assuming 33MHz system bus speed for PIO modes; override with idebus=xx
PIIX4: IDE controller on PCI bus 00 dev 39
PIIX4: chipset revision 1
PIIX4: not 100% native mode: will probe irqs later
    ide0: BM-DMA at 0xf000-0xf007, BIOS settings: hda:DMA, hdb:DMA
    ide1: BM-DMA at 0xf008-0xf00f, BIOS settings: hdc:DMA, hdd:DMA
hda: WDC WD400JB-00ENA0, ATA DISK drive
hdc: WDC WD400JB-00ENA0, ATA DISK drive
hdd: LTN382, ATAPI CD/DVD-ROM drive
ide0 at 0x1f0-0x1f7,0x3f6 on irq 14
ide1 at 0x170-0x177,0x376 on irq 15
blk: queue c0365884, I/O limit 4095Mb (mask 0xffffffff)
hda: 78165360 sectors (40021 MB) w/8192KiB Cache, CHS=4865/255/63, UDMA(33)
blk: queue c0365be8, I/O limit 4095Mb (mask 0xffffffff)
hdc: 78165360 sectors (40021 MB) w/8192KiB Cache, CHS=77545/16/63, UDMA(33)

[Kelvin]

Hi Robert,

Have you checked your CMOS settings by any chance. Most BIOSes allows you to configure LBA / CHS translation on a drive by drive basis.

Just a thought.

Kelvin

[Dan Williamson]

Your drive geometries are different. They should be set identically in the CMOS if possible. The odds are it shouldn't affect the ability for you to run RAID0 mirroring with them but I would do it just as a precaution.