On Sunday 28 January 2007 11:02, Patrick Useldinger wrote:
> I am currently experimenting with ccd(4) and although it appears to
> work, I am uncomfortable with one point.
>
> I have configured 2 partitions as a JBOD (interleave 0). However, the
> first of these partitions is partition 'a' of one disk. So the first
> effect I had was that ccd0 appeared to have the same disklabel as the
> first disk.
man ccd:
"Note that the `raw' partitions of the disks should not be combined. Each
component partition should be offset at least one cylinder from the beginning
of the component disk."
see also thread on misc:
CCD: started on 17 jan 2007 by Chris Mika
how much one cylinder is, can be calculated with the numbers given by
disklabel. ight about the following point but:
i would not use partition 'a' for anything else then my boot partition.
thus i never used 'a' as a member of a ccd, nor did i create an 'a' on
a ccd.
unfortunatly disklabel -E ccd0 did not work for me after 'fdisk -i ccd0',
since 'ccd0c' had type '4.2BSD' not 'unused' as for raw devices. since the
FAQ sais:
"Just use disklabel on it like you normally would to make the partition or
partitions you want to use. Again, don't use the 'c' partition as an actual
partition that you put stuff on."
i used 'disklabel -e ccd0' to change the type to 'unused'. after that i
created one big partition 'd' on the ccd0 drive.
//llx
>
> I read through the mailing list archives and found a thread explaining
> that the disklabel is stored around the beginning of partition 'a' and
> that one should allocate a small partition 'a' which should not be made
> part of the JBOD.
>
> What I am uncomfortable with is that
>
> 1) this does not appear to be documented in the man pages anywhere
>
> 2) that the size and position of the disklabel of partition 'a' is not
> clearly stated anywhere so that I can be certain that it doesn't get
> overwritten and that I am not wasting too much space.
>
> Can anybody please shed some light on this?
>
> Regards,
> -pu
