Re: safe file systems

Leonard N. Zubkoff (
Thu, 25 Sep 1997 12:17:15 -0700

From: (Larry McVoy)
Date: Wed, 24 Sep 1997 12:22:23 -0700

The default on every SCSI & FC disk I've ever seen (and I've seen a
fair number including drives from HP, Seagate, Quantum, IBM, Maxstor,
and probably others I'm forgetting) is to /not/ do write caching. If
the drive says the write is done, it is done.

You can, as you mentioned, change this behavior, but the default as shipped
from the vender is that it does not do write caching.

And no work station vendor (Sun/SGI/HP) that I know of turns them on - it
would be highly unreasoable to do so.

I suspect that your experience is colored by receiving drives that were
specifically ordered with the default that the write cache was disabled. The
Quantum Atlas II drives I've purchased recently all had both caches enabled,
for example. I suspect the vendors do this for the retail market to avoid
people benchmarking their products and finding poor results.