Messages in this thread |  | | Date | Sat, 22 Jun 1996 17:23:58 +0200 (MET DST) | From | Michael Neuffer <> | Subject | Re: SCSI device numbering (was: Re: Ideas for v2.1 |
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On Thu, 20 Jun 1996, Eric Youngdale wrote: > Consider that some cards drive multiple channels. Currently some > cards support 2,
Make that 5.
> I have seen some people argue for solutions that work for the small > systems, but exclude the large systems. I believe that this is fundamentally > wrong, since the problems with dynamic address shifting grow as the number > of devices on the sysetem grow. We should be looking for solutions that > work in the case of large systems (with say 500 or more disk drives), and > then make sure that this works well for the small systems. > > The scsidev program is basically sort of a band-aid until a better > solution arrives. I do believe that it should alleviate most of the > problems that people are having until that time comes.
Another thing that would help would be to give very disk and partition a unique name in the system. That way it would make no more problems to move a drive from controller A channel B ID C to controller D channel E ID F, it would be possible to move disks around in the system without getting problems everytime if you forget to update the fstab.
The fstab could look like this: root / ext2 defaults 1 1 usr /usr ext2 defaults 1 2 home1 /home/u1 ext2 defaults 1 2 home2 /home/u2 ext2 defaults 1 2 var /var ext2 defaults 1 2 tmp /tmp ext2 defaults 1 2 postgres /postgres ext2 defaults 1 2 none /proc proc defaults 1 2 swap1 none swap swap2 none swap swap3 none swap
Convex (now HP supercomputer divison) has implemented this and it has proven to be very useful.
> Note that with the current system, there can be a maximum of 16 disk > drives (since 16 * 16 partitions = 256 = max minor number). Clearly a larger > dev_t is needed, no matter how we do it.
Yes, nomis.i-connect.net for example is one machine that is operating almost at this limit.
> We need to somehow agree on how > large this needs to be, and *then* we need to fix the filesystems so that > they store a dev_t that is this large.
My vote goes for 64+bits
Mike
Michael Neuffer i-Connect.Net, a Division of iConnect Corp. mike@i-Connect.Net 13455 SW Allen Blvd., Suite 140 503.677.2900 Beaverton, OR 97008
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