3x read to write ratio on dump/restore
Ollivier Robert
roberto at keltia.freenix.fr
Mon Jan 12 03:20:57 PST 2009
According to M. Warner Losh:
> The read kBps was 3x the write kBps. While the dump is going through
> the raw device, and the restore is going through the file system, I
> can't imagine why we'd have such a huge difference that would be utter
> consistent for the whole 15 hour run.
dump launches several processes to read the raw device and use a buffer
between them whereas restore is single process. When copying from disk to
disk, I often use team (sysutils/team) to stream.
--
Ollivier ROBERT -=- FreeBSD: The Power to Serve! -=- roberto at keltia.freenix.fr
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