Subject: Re: VPS mailing list, BSD interest?
To: Jason Thorpe <thorpej@nas.nasa.gov>
From: James Graham <greywolf@siva.captech.com>
List: tech-kern
Date: 10/01/1996 12:43:23
Jason Thorpe sez:
#
# [Poul-Henning Camp sez]:
# > There is no significant difference between the FDISK, bsd-disklabel,
# > mirror, stripeing and raid 5 operations. They all translate a
# > (dev+blkno+len) tupple to one or more similar tupples.
1. Minor nit: (x+y+z) is a triple, not a tuple.
2. There is no difference between the operations? You've obviously
not dealt with a RAID5 filesystem before. Nice idea, but you pay
for it with performance. And yes, I consider performance significant.
The first time I ran the ccdconfig thing and tried to newfs it,
I ended up running it on unevenly sized filesystems (OK) with an
interleave of 1 (NOT OK!). Boy, was THAT _slow_! Not to mention
I wanted concatenation anyway... :-)
I haven't had the opportunity to stripe or mirror a filesystem yet
(insufficient disk space and differently-sized disks make this a
bit of a challenge), so I can't comment on performance. But it's nice
to have the concatenation as when I partitioned my disks, I had one piddly
partition of 70MB left over. Seeing as that wasn't really enough with
which to do jack, I concatenated it to my user disk.
#
# Jason R. Thorpe thorpej@nas.nasa.gov
# NASA Ames Research Center Home: 408.866.1912
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--*greywolf;