File system blocks alignment
phk at phk.freebsd.dk
Fri Dec 25 18:18:25 UTC 2009
In message <4B34C619.7070505 at FreeBSD.org>, Alexander Motin writes:
>Poul-Henning Kamp wrote:
>- Second is a row size - stripe size * number of data disks. You may
>freely read less information then full row, but short write cause RAID
>to handle read-modify-write scenario.
There is a far worse scenario: a stripe-spanning write, it forces a
RMW cycle over two different RAID5 stripes.
Poul-Henning Kamp | UNIX since Zilog Zeus 3.20
phk at FreeBSD.ORG | TCP/IP since RFC 956
FreeBSD committer | BSD since 4.3-tahoe
Never attribute to malice what can adequately be explained by incompetence.
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