Re: [linux-lvm] Re: [Announce] device-mapper beta3 (fast snapshots)

[Patrick Caulfield <caulfield sistina com>]

On Tue, Jul 16, 2002 at 01:27:24PM -0400, Chris Mason wrote:
> On Tue, 2002-07-16 at 12:31, Joe Thornber wrote:
> 
> > > Joe, are you absolutely sure these tests had the disk cache disabled?  That's
> > > the only hardware thing I can think of that would make a difference.
> > 
> > Absolutely sure.  Those figures were for a pair of PVs that were
> > sharing an IDE cable so I can certainly get things moving faster.
> 
> Some IDE drives ignore commands to turn off the write back cache, or
> turn it back on when load gets high.
> 

I have reproduced Joes flat graph with SCSI & Fibre-channel drives so I wouldn't
read too much into his cabling :-)

patrick