On Sat, Mar 02, 2002 at 01:44:09PM +0000, Sung N. Cho wrote:
> Hi,
> 
> I heard that by using ccd (concatenated/striped disk devices), one can 
> improve the disk I/O.  I read the manual (ccd) but it's more of dictionary of 
> what ccd is and does.  It fails to describe how to set it up.  Anybody knows 
> how to set this up?  Here's my disklabel info:
> 
> # /dev/rwd0d:
> type: unknown
> disk: mydisk
> label:
> flags:
> bytes/sector: 512
> sectors/track: 63
> tracks/cylinder: 15
> sectors/cylinder: 945
> cylinders: 10068
> total sectors: 9514260
> rpm: 3600
> interleave: 1
> trackskew: 0
> cylinderskew: 0
> headswitch: 0           # microseconds
> track-to-track seek: 0  # microseconds
> drivedata: 0
> 
> 8 partitions:
> #        size    offset     fstype  [fsize bsize cpg/sgs]
>  a:    204120    725760     4.2BSD   1024  8192    80   # (Cyl.  768 - 983)
>  b:    524475    929880       swap                      # (Cyl.  984 - 1538)
>  c:   8788500    725760     unused      0     0         # (Cyl.  768 - 10067)
>  d:   9514260         0     unused      0     0         # (Cyl.    0 - 10067)
>  e:    103005   1454355     4.2BSD   1024  8192    96   # (Cyl. 1539 - 1647)
>  f:   6624450   1557360     4.2BSD   1024  8192    80   # (Cyl. 1648 - 8657)
>  g:   1332450   8181810     4.2BSD   1024  8192     0   # (Cyl. 8658 - 10067)
>  h:    725697        63      MSDOS                      # (Cyl.    0*- 767)
> 
> 

You have only one disk ?
ccd improves disk I/O by spreading the load accross several disks. With
only one disk ccd won't help at all.

-- 
Manuel Bouyer <bouyer@antioche.eu.org>
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