Re: Linux-sony digest, Vol 1 #710 - 3 msgs

[email protected] wrote:
> Date: Mon, 18 Aug 2003 22:50:57 -0400
> From: George Silberstern <[email protected]>
>
> At 09:58 PM 8/17/2003 -0700, you wrote:
> >As I mentioned in my second email, nothing gets written to anything in
> >/var/log/ when the MS is inserted or removed.
> >
> >It's got to be around there somewhere.  'cdrecord -scanbus' reports the
> >following (which is just another format of the 'lshw' output):
> >
> >scsibus0:
>
> This is /dev/sda...
>
> >scsibus1:
>
> ....and this is /dev/sdb...

Actually, that's not correct.  It may be what you've seen in most
situations, but the scsi bus doesn't work that way.  scsibus0 will have
some number of devices attached to it (for example, let's say there are
3).  Those devices will be /dev/sda, /dev/sdb, and /dev/sdc.  If there are
also devices on scsibus1, they will be devices /dev/sdd, /dev/sde, and so
on for each scsi bus in the system.

Software scsi emulation doesn't really change any of this, although for
performance reasons, scsi emulation tries to spread the devices allocated
across scsi buses (sort of like multiple spindles in a RAID array,
although the spindles are physical and the reason for the spread in scsi
emulation is software).

Unfortunately, this means that your device names can change depending on
what's hooked up to the box.  I never understood why partition names
aren't assigned to logical devices.  For example, on my circa 1986 Amiga
each partition was assigned a label by the OS (such as "Work:") and the
user could assign their own name as well (such as "Backup:").  Even if
drives were re-ordered on the scsi bus, they kept their user-assigned
names the same and if the user only used those names, they were isolated
from configuration changes on the machine.

> ....therefore, all is right in the world --well, mostly...
>
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>   :=========================================================================:
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HTH
--
Frank J. Edwards
Edwards & Edwards Consulting
sales-at-eec.com