On Wednesday 21 May 2008, Jamie Lokier wrote:

Theodore Tso wrote:

quoted

On Wed, May 21, 2008 at 11:03:24AM -0700, Andrew Morton wrote:

quoted

afaik there is no need to enable this feature if the machine (actually
the disks) are on a UPS, yes?

Yes, as long as you're confident that there won't be a kernel
bug/regression causing a lockup while the server is under severe
memory pressure while doing lots of fsync's, file creations, renames,
etc.  And as long as your 100% confident that UPS's will never fail,
janitors will never accidentally hit the Emergency Power Office

Can a kernel lockup cause this kind of corruption?

No

Will a system reboot wipe the disk's write cache?

Only if you reboot with the power switch (some test rigs do)

I had imagined only power loss would prevent the disk from
writing it's cache eventually; is that wrong?

-chris