> Well the readahead "issues" are just the zfs design, AFAIK. It does > aggressive prefetching to improve performance on the assumption that you > are running with a reasonably fast storage system that can keep up. On > crappy low end disk hardware (e.g. single ATA disk) this can easily > saturate the disk. Well, regardless of the absolute performance you don't want the read-ahead to consume to much of the relative bandwidth/seek time available. Personally I didn't experience any prooven issues with prefetch; I disabled it on general recommendation back in the i386/1gb days and told myself I saw an improvement. I never looked into it carefully, other than that I previously had a general feeling that I saw a lot more I/O on the pool than what was read by applications. My memories are vague. -- / Peter Schuller PGP userID: 0xE9758B7D or 'Peter Schuller <peter.schuller_at_infidyne.com>' Key retrieval: Send an E-Mail to getpgpkey_at_scode.org E-Mail: peter.schuller_at_infidyne.com Web: http://www.scode.org
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