qemu-devel
[Top][All Lists]
Advanced

[Date Prev][Date Next][Thread Prev][Thread Next][Date Index][Thread Index]

Re: [Qemu-devel] iSCSI support for QEMU


From: Christoph Hellwig
Subject: Re: [Qemu-devel] iSCSI support for QEMU
Date: Thu, 21 Apr 2011 14:49:38 +0200
User-agent: Mutt/1.5.17 (2007-11-01)

On Thu, Apr 21, 2011 at 09:36:12PM +1000, ronnie sahlberg wrote:
> There are some high-volume arrays that advertise support but fail any
> cdb with FUA, FUA_NV bits set with sense, so it needs to be made optional.

Which on would that be?  Linux uses the FUA bit if the device advertises support
via the DPOFUA bit since 2005, and prints a warning if a FUA write fails,
and since last year even fails the request hard.  I'd be really surprised
if a common device fails FUA writes and we didn't know about it by now.

Either way you'll have to still guarantee data made it to non-volatile
storage for cache=writethrough mode, either by disabling the WCE bit
using MODE SELECT, or by flushing the cache after every write.



reply via email to

[Prev in Thread] Current Thread [Next in Thread]