Messages in this thread | | | Date | Fri, 14 Mar 2008 15:29:12 -0400 | From | Theodore Tso <> | Subject | Re: writeback cache dangers Re: [ANNOUNCE] Ramback: faster than a speeding bullet |
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On Fri, Mar 14, 2008 at 08:03:57PM +0100, Pavel Machek wrote: > > > The ingest rate at the time of a power hit makes a huge > > difference as well - basically, pulling the power cord > > when a box is idle is normally not harmful. Try that > > when you are really pounding on the disks and you will > > see corruptions a plenty without barriers ;-) > > I tried that, and could not get a corrruption. cp -a on big kernel > trees, on sata disk with writeback cache and no barriers... and I > could not cause fs corruption. ext3. > > I'd like to demo danger of writeback cache. What should I do?
Ext3's journal probably hides a huge number of problems. I'd try something with a lot more parallel modifications to metadata. Say postmark with a large number of threads. It would be interesting actually to get some controlled results of exactly how busy a filesystem has to be before you get filesystem corruption (which I would check explicitly running "e2fsck -f" e2fsck after pulling the plug on the drive).
- Ted
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