Re: EXT intent logging

[Thomas Zimmerman]

On 06-Aug 03:56, Theodore Ts'o wrote:
> "mount -o data=journal" logs metadata blocks and data blocks into
> journal first, and then after the transaction commits, the metadata
> and data blocks are written to their final location on disk.  The
> problem with this is that all your write bandwidth is cut in half
> since all block writes get written twice to disk --- once to the
> journal, and once to the final location on disk.

While you do half your write bandwidth, there arn't any _seeks_ while
writing to the journal. For IO workloads where a sync allows you to
move on to another job, this can speed up your workload. Mail delivery
on an old laptop disk was ~2 as fast using ext3 data=journal...

Thomas
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