On Fri, 5 Jun 2009, blee2@tampabay.rr.com wrote:
> This week I've been working on cloning some SUN disks using dd.
>
> In case anyone else has reason to need to do this, the command I'm using on theis SUN 220R is:
>
> dd if=/dev/rdsk/c0t0d0s2 of=/dev/rdsk/c0t0d0s2 bs=10485760
> where
> dsk refers to the disk device
> rdsk refers to the raw disk
> c0 is SCSI controller 0
> t0 is Target 0
> d0 is disk 0
> s2 is slice (partition) 2
> bs is the number of bytes to read and write at a time
> 10485760 is 10 megabytes
>
>
> Slices are what SUN calls a partition. Slice 0 is root, starting around
> block 445. Slice 1 is swap, starting at 0 going to 444. Slice 7 is home
> starting around block 1000. Slice 2 is interesting: called "backup"
> it is defined as ALL blocks on the disk, starting at 0, going through
> the end of the disk. It overlaps the other slices. Slices 3 through
> 6 are undefined.
>
> Testing indicates the partition table of the target will be overwritten
> with the the partition table of the source.
>
> You should fsck the partitions on the target drive after the clone.
>
> QUESTION:
> Can anyone think of a reason to put the swap at the beginning of the disk?
> I always try to put my swap in the MIDDLE of the disk for lowest latency.
> This may not be a SUN default and was just something the guy who built
> this server 3 years ago did.
If you assume that the blocks are numbered starting at the outer edge moving
inward, then (since hard drives rotate at a constant velocity) you'd get the
highest throughput on lower-numbered blocks. I don't know how you can know
that, given multiple platters and transparent bad-block replacement.
--
-eben QebWenE01R@vTerYizUonI.nOetP royalty.mine.nu:81
> A: It's annoying as hell
> Q: Why do most people hate top-posting? -- Lots42 The Library Avenger
http://www.fscked.co.uk/writing/top-posting-cuss.html
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