[Beowulf] Re: RAID for home beowulf
hahn at mcmaster.ca
Tue Oct 13 22:41:13 PDT 2009
> 3) Be aware that the kernel you are using will make a big
> difference and that the semantics for ext3 have changed
> a while ago so that it no longer uses data=ordered but
> instead uses data=writeback by default (you can override
AFAIKT, it's just an option for the default mount config now
that wasn't offered before. major distros (I only checked fedora)
still do data=ordered, and the latest kernel snapshot still has
data=ordered as the default.
the kernel config help text points to this:
which makes a useful point about app-level consistency still requiring
fsyncs (which operates above any fs-level consistency guarantees.)
also, I find swapfiles more convenient than partitions. some installers
always force a swap partition to the tail of the disk, which is pessimal.
regards, mark hahn.
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