Best practices for using gjournal with gmirror?
lists at jnielsen.net
Thu Jan 11 04:21:03 UTC 2007
I have a few questions for pjd (or anyone else) about using gjournal,
particularly when used with gmirror.
1) I'm running 6-STABLE and plan to test with gjournal6_20061030.patch (from
the mailing list; updated version of 20061024 that applies cleanly). Is
there a better/newer version for -STABLE that I should use instead?
2) When using gjournal and for a gmirror volume, does the journal need to be
mirrored as well to maintain redundancy? If so, when storing the journal on
the same physical disks as the mirror, is it better to mirror at the slice
level (journal and fs on different partitions in the same mirror) or at the
partition level (journal and fs each have their own mirror) or does it
3) I remember reading where pjd said that gjournal plus gmirror or graid3
would eliminate the need to re-sync the array after a crash. While clearly
a design goal, is that actually the case with the version of the patch
mentioned above? If so, are any config changes needed or will it just
4) In the same vein as 3)--does a gjournal volume need to be fsck'ed after a
crash? If not, will it just work (e.g. fsck -p sees that the filesystem is
clean) or does it need to be disabled somehow?
5) Finally, how dangerous is this code? I realize it's experimental and only
plan to use it with data that has recent backups, but how much should I
worry about it blowing up my system or corrupting my files?
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