Subject: Re: dump is slow
To: What EES eet man? <>
From: Manuel Bouyer <>
List: tech-userlevel
Date: 03/03/1999 12:18:08
On Mar 2, What EES eet man? wrote
> [tested on SS IPX 64M, root disk is Seagate ST1480N - not the slowest disk
>  in the world, certainly faster than the MICROP 1588-15 in there!]
> Interestingly I found that dumping 20MB at 32k transfers to /dev/null
> averaged 453K/sec, while dumping at 64k transfers to /dev/null averaged
> 415K/sec.
> Curiously, does dump take BLOCKSIZE into account when specifying number
> of blocks ('b' option)?  This would be a BAD thing, in my opinion, because
> in single-user mode, one might have BLOCKSIZE defaulting to 512, while in
> multi-user mode, it might be set to 1k.  Guess what happens when you
> read back tapes?  Could we make BLOCKSIZE something of a constant for
> tape handling?

No, dump doesn't use BLOCKSIZE.

Manuel Bouyer, LIP6, Universite Paris VI.