Subject: Re: partition bookkeeping
To: Oleg Polyanski <email@example.com>
From: Ignatios Souvatzis <firstname.lastname@example.org>
Date: 09/23/1999 21:21:34
On Thu, Sep 23, 1999 at 10:37:46PM +0400, Oleg Polyanski wrote:
> >>>>> "IS" == Ignatios Souvatzis writes:
> IS> Maybe I should add that for normal booting, root devices tend to not
> IS> change their name all the time, so having the sysadmin edit fstab once
> IS> at installation or reconfiguration time is good enough.
> >> Consider my disk has name `sd0' (because it was detected first during
> >> the kernel booting). Later I will add ZIP drive and IT will get the name
> >> `sd0' and hard disk will become `sd1'. Bad surprise, manual intervention
> >> required. Something like `/dev/scsi/dsk/c0d0p0' as root fs unique
> >> identifier will help.
> IS> If you insist to make your boot drive scsi id 1, and not having any
> IS> fixed disk scsi id 0, you can still wire down the sd unit of your root
> IS> disk in your kernel configuration.
> OK, here are excerpts from my `dmesg' output:
> NetBSD 1.4K (TINDERBOX) #1: Sat Sep 18 15:08:22 MSD 1999
> cpu0: family 6 model 5 step 1
> cpu0: Intel Pentium II (Deschutes) (686-class)
> pciide0 at pci0 dev 7 function 1: Intel 82371AB IDE controller (PIIX4)
> pciide0: bus-master DMA support present
> pciide0: primary channel wired to compatibility mode
> atapibus0 at pciide0 channel 0
> sd0 at atapibus0 drive 1: <IOMEGA ZIP 100 ATAPI, , 23.D> type 0 direct removable
> sd0: drive offline
> sd0: 32-bits data port
> pciide0: primary channel interrupting at irq 14
> sd0(pciide0:0:1): using PIO mode 3
> pciide0: secondary channel wired to compatibility mode
> atapibus1 at pciide0 channel 1
> ncr0 at pci0 dev 16 function 0: ncr 53c875 fast20 wide scsi
> ncr0: interrupting at irq 10
> ncr0: minsync=12, maxsync=137, maxoffs=16, 128 dwords burst, large dma fifo
> ncr0: single-ended, open drain IRQ driver, using on-chip SRAM
> ncr0: restart (scsi reset).
> scsibus0 at ncr0: 16 targets, 8 luns per target
> sd1 at scsibus0 targ 1 lun 0: <SEAGATE, ST52160N, 0285> SCSI2 0/direct fixed
> sd1(ncr0:1:0): 20.0 MB/s (50 ns, offset 15)
> sd1: 2069 MB, 6536 cyl, 4 head, 162 sec, 512 bytes/sect x 4238282 sectors
> sd2 at scsibus0 targ 2 lun 0: <SEAGATE, ST36530N, 1206> SCSI2 0/direct fixed
> sd2(ncr0:2:0): 20.0 MB/s (50 ns, offset 15)
> sd2: 6208 MB, 9006 cyl, 6 head, 235 sec, 512 bytes/sect x 12715920 sectors
> So, what you mean when you say `you can still wire down the sd unit
> of your root disk in your kernel configuration'?
you can write "sd1 at scsibus0 targ 1 lun 0" into the kernel configuration file,
and it will always have unit 1, independent of other devices on the scsi bus.
Or even "sd0 at scsibus0 targ 1 lun 0", to make it always unit 0, in case
you find this more pleasing.
or any other number. But be warned that our current cloning config entry
implementation (the magic with the *) always uses one more than the highest
fixed unit number for the first cloned unit number.