Re: scsi disk detection and /dev names, RE: My $.02 on the raging

Paul Jakma (paul@clubi.ie)
Tue, 12 Oct 1999 00:01:58 +0100 (IST)



Are you trying to get me into this idiotic discussion?

eh??? hey you replied to me.. (shakes head)

Look: If you like devfs - fine, so use it.

no no no no... i don't want devfs involved in this!!! rustig aan! :)
I only mentioned devfs soley because it provides this useful feature,
which i believe should be in the kernel anyway... never mind the rest
of devfs - wrong thead.

what i want to discuss is the deficiency of linux's scsi device
allocation, and how to improve it.

(i) Use UUID - works today (for ext2), but requires some initrd hackery
if you want to use it also to find the root device.
(ii) Use scsidev - works today (for scsi), but requires some initrd hackery
if you want to use it also to find the root device.

i don't like either of the above.. they're not robust enough. UUID
doesn't cover everything. (md devices for one). scsidev could
conceivably cause loads of problems, eg situation where scsidev fails
to run but admin doesn't notice. Both the above are more dangerous
than traditonal detection ordered /dev/sdx nodes IMO.

(iii) Assign device IDs to devices that encode SCSI ID and all the rest.
Easy, if one has large device numbers. Easy to do. I did it a few times.
Maybe some official kernel will have them one of these centuries.

yes.. sounds exactly like it. native location-based scsi device
major/minors, to avoid all possibility of user and kernel not
agreeing on which disk is which device. That's the cleanest way.

Guess this needs larger kernel dev_t field.

groetjes,

-- 
Paul Jakma	paul@clubi.ie
PGP5 key: http://www.clubi.ie/jakma/publickey.txt
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