gjournal alignment on 4K sector advanced format drives
ivoras at freebsd.org
Tue Aug 31 12:19:52 UTC 2010
On 08/31/10 13:09, Carl wrote:
> Now I want to add gjournal to some of my partitions. It seems to me that
> I must also ensure the journal is aligned just as I've done with the
> data. So far, though, I have found no information as to how the
> journal's own filesystem layout works. Does it use fixed size
> blocks/fragments like the UFS2 data does? If so, what is its minimum
> addressable unit size? If it is smaller than 4KiB, we get journal
> misalignment and a performance loss, right? What must I do to ensure the
> journal is fully aligned?
gjournal writes its metadata throughout the journal in sector sizes (512
bytes) so it cannot be aligned in this way.
For this you need a solution which will actually change the sector size,
like gnop or my glabel patch.
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