On Thu, 31 Mar 2011, Eric Sandeen wrote: > On 3/31/11 5:21 PM, Andreas Dilger wrote: > > > We have a kernel patch "dev_read_only" that we use with Lustre to > > disable writes to the block device while the device is in use. This > > allows simulating crashes at arbitrary points in the code or test > > scripts. It was based on Andrew Morton's test harness that he used > > for ext3 recovery testing back when it was being ported to the 2.4 > > kernel. > > > > http://git.whamcloud.com/?p=fs/lustre-release.git;a=blob_plain;f=lustre/kernel_patches/patches/dev_read_only-2.6.32-rhel6.patch;hb=HEAD > > > > The best part of this patch is that it works with any block device, > > can simulate power failure w/o any need for automated power control, > > and once the block device is unused (all buffers and references > > dropped) it can be re-activated safely. > > It won't simulate a lost write cache though, will it? That's a very good question, I would like to know if there is any way at all to force the device to drop the write cache. That would really help the power failure testing filesystems. -Lukas > > -Eric > -- > To unsubscribe from this list: send the line "unsubscribe linux-ext4" in > the body of a message to majordomo@xxxxxxxxxxxxxxx > More majordomo info at http://vger.kernel.org/majordomo-info.html > -- To unsubscribe from this list: send the line "unsubscribe linux-ext4" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
