Messages in this thread |  | | Date | Wed, 10 Oct 2001 19:33:55 -0600 | From | Richard Gooch <> | Subject | Re: Dump corrupts ext2? |
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Andreas Dilger writes: > On Oct 10, 2001 19:11 -0400, Doug McNaught wrote: > > Lew Wolfgang <wolfgang@sweet-haven.com> writes: > > > I was looking for some scripts to backup ext2 partitions > > > to multiple CDR's when I stumbled onto "cdbackup" at > > > http://www.cableone.net/ccondit/cdbackup/. > > > > > > Alas, there is a warning saying: > > > > > > "WARNING! When using this program under Linux, be sure not to use > > > dump with kernels in the 2.4.x series. Using dump on an ext2 > > > filesystem has a very high potential for causing filesystem > > > corruption. As of kernel version 2.4.5, this has not been > > > resolved, and it may not be for some time." > > > > I'm pretty sure this is because dump reads the block device directly > > (which is cached in the buffer cache), while the file data for cached > > files lives in the page cache, and the two caches are no longer > > coherent (as of 2.4). > > In Linus kernels 2.4.11+ the block devices and filesystems all use > the page cache, so no more coherency issues.
Um, I thought that there wasn't going to be coherency? For example, if you open /dev/sda and /dev/sda1, they each have a separate cache. I remember some debate about this, and Linus pointed out how hard it was to make things coherent.
Regards,
Richard.... Permanent: rgooch@atnf.csiro.au Current: rgooch@ras.ucalgary.ca - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
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