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    SubjectRe: Disk schedulers
    Lukas Hejtmanek wrote:
    > whom should I blame about disk schedulers?
    > I have the following setup:
    > 1Gb network
    > 2GB RAM
    > disk write speed about 20MB/s
    > If I'm scping file (about 500MB) from the network (which is faster than the
    > local disk), any process is totally unable to read anything from the local disk
    > till the scp finishes. It is not caused by low free memory, while scping
    > I have 500MB of free memory (not cached or buffered).
    > I tried cfq and anticipatory scheduler, none is different.
    > ----
    You didn't say anything about #processors or speed, nor
    did you say anything about your hard disk's raw-io ability.
    You also didn't mention what kernel version or whether or not
    you were using the new UID-group cpu scheduler in 2.6.24 (which likes
    to default to 'on'; not a great choice for single-user, desktop-type
    machines, if I understand its grouping policy).

    Are you sure neither end of the copy is cpu-bound on ssh/scp
    encrypt/decrypt calculations? It might not just be inability
    to read from disk, but low cpu availability. Scp can be alot
    more CPU intensive than you would expect... Just something to


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