Subject: Re: dump is slow
To: Justin T. Gibbs <>
From: What EES eet man? <>
List: tech-userlevel
Date: 03/02/1999 10:33:54
[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

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?

ALSO, on another tangent:  My EXB-8200 doesn't seem to like handling
transfers of larger than 32KB/transfer (32b@BLOCKSIZE=1k).  It goes on
for a wee bit and then hangs.  The throughput also seems to be atrocious.
Theoretically the largest transfer possible by the EXB is 63k, or it
used to be under StunOS.  What's going on?

Humanocentric religions and ways of life have proven to be our undoing.