Messages in this thread |  | | Date | Wed, 10 Oct 2001 17:38:11 -0700 | From | Mike Fedyk <> | Subject | Re: Dump corrupts ext2? |
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On Wed, Oct 10, 2001 at 07:11:43PM -0400, Doug McNaught wrote: > Lew Wolfgang <wolfgang@sweet-haven.com> writes: > > > Hi Folks, > > > > 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 don't recall any problems like this, does anyone have > > additional comments? > > 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). >
IIRC, 2.2 didn't have a coherent buffer and page cache also.
I.E. if you "cat /dev/hda > /dev/null" you wouldn't be able to expect any speedup when reading through the mounted filesystem (except for meta-data?).
Am I wrong? Has Linux ever had a coherent page and buffer cache? - 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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