Subject: Re: partition bookkeeping
To: Ignatios Souvatzis <>
From: Oleg Polyanski <>
List: tech-kern
Date: 09/23/1999 00:34:57
>>>>> "IS" == Ignatios Souvatzis writes:

 >> >> I'm not sure that it makes our life easier.  Right now we have
 >> floating >> disk naming scheme - disk detected first will get number `0'
 >> even if it >> has, for example, SCSI ID 5 so when I add another disk with
 >> SCSI ID >> number 2 (for example, I would like to add large /opt file
 >> system) it >> becomes first (i.e.  sd0), not the former `first' disk.
 >> You cannot mount >> root fs without editing your `/etc/fstab'.  It's
 >> weird.  Disk naming >> scheme must depend on device physical properties
 >> (SCSI ID, master/slave >> or something like that).
 IS> This won't help you to mount root. You have to _know_ at _runtime_ which
 IS> one it is. As this isn't generally possible (at best, the kernel knows
 IS> it), install scripts tend to mount kernfs and then mount /kern/rootdev.
 >>  Sorry, forgot to say `mount root fs for read/write'.

 IS> Yes, this was evident, and is exactly what I'm referring to.

 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.