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    SubjectRe: faster boots?
    Hi!

    > > It works for me, 2.4.18 on HP omnibook xe3.
    > >
    > > You may want to watch /proc/stats to see if it is read or write
    > > activity that wakes disk up.
    >
    > It's write activity, due to atime updates. I was using nodiratime, but
    > that's not good enough because every time an executable is run a load of
    > things are accessed.
    >
    > I found it interesting that some write activity happens almost
    > immediately after the access -- and noflushd is connected in some way.
    > If I do this:
    >
    > while :; do cat /proc/stat; sleep 1; done
    >
    > Then I see a few writes have occurred at nearly every iteration. I
    > think that is due to the atime updates, because using "noatime" there
    > are no writes at most iterations.

    Well, that's no problem. noflushd stops kflushd, so it should work
    even with atime. [It works for me with atimes!]

    > But more interesting: I only see those few-per-second atime writes while
    > noflushd is running. If I kill noflushd then they go away.

    ?

    > I am a bit surprised that "noatime" makes a difference -- I thought that
    > if noflushd spun down a disk, then pending inode writes should be
    > delayed until a read or excess memory pressure forces a spin up.

    Tha'ts idea behind noflushd. I don't know why it does not work for
    you.

    > So: "noatime" is definitely required, to spin the disk down for more
    > than an instant. But even that is not good enough. I have 192MB RAM,
    > btw. Is that enough to expect longer spin down times than 20s?

    With noflushd, noatime should not and is not required.

    Pavel
    --
    Casualities in World Trade Center: ~3k dead inside the building,
    cryptography in U.S.A. and free speech in Czech Republic.
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