Re: [Qemu-devel] [RFC] Disk integrity in QEMU

[Jamie Lokier]

Avi Kivity wrote:
> The IDE write cache is not susceptible to software failures (well it is 
> susceptible to firmware failures, but let's ignore that).  It is likely 
> to survive reset and perhaps even powerdown.  The risk window is a few 
> megabytes and tens of milliseconds long.

Nonetheless, from yanking the power relatively often while using ext3
(this is on a host only, no qemu involved) I've seen a number of
corruption cases, and these all went away when the IDE write cache was
disabled, or when IDE write barriers were used.

This is a failure case which happens in real life, but not often if
you don't often yank the power during writes.

Just so you know.

-- Jamie