On Dienstag 03 Februar 2009 Eric Sandeen wrote:
> you'd need to read the docs for your controller, to find out how to
> tell if it has a writeback cache enabled, and whether it is
> batter-backed or not.
Sorry I didn't write that. Yes it's writeback (can be switched off) and
it's battery backed. Is there no danger then? Because in the mail from
Chris, he wrote he got problems because there was "with a write back
cache enabled on the controller / disks but without barriers". And I
thought the (not supported/used) barriers could be a problem.
I've re-read the FAQ now. It says it's recommended to turn off barrier
writes if you have battery-backed writeback, and I guess I'll do that.
So I misunderstood Chris.
But what about the hard disk cache - should that be disabled? I think in
case of a power failure, they just loose their cache contents, right? So
the battery-backed controller cache only helps himself, the disks will
just throw away up to the 32MB cache they have?
// Michael Monnerie, Ing.BSc ----- http://it-management.at
// Tel: 0660 / 415 65 31 .network.your.ideas.
// PGP Key: "curl -s http://zmi.at/zmi.asc | gpg --import"
// Fingerprint: AC19 F9D5 36ED CD8A EF38 500E CE14 91F7 1C12 09B4
// Keyserver: wwwkeys.eu.pgp.net Key-ID: 1C1209B4