On Thu, 2005-01-20 at 09:13 +1100, Les Bell wrote: > The objection to "wasting" a few GB of disk space doesn't carry much > weight, since a machine with a GB or more of RAM usually has a few hundred > GB of disk attached.
Ever thought about runaway processes, hitting swap, on a slow disk (like those on laptops), that the OOM doesn't get to? Yes, this happens > That theory is attractive, and I subscribed to it myself for a while - but > then I figured out the fly in the ointment. When the Linux kernel runs out > of memory (that is, uses up the total of both RAM and virtual memory in the > swap partition), it finds itself backed into a corner it can't get out of. > With no memory to run error-handling code, it can't handle the error, and > the result is an ugly crash. (Linux is not alone in this behaviour - many > if not most operating systems die an ugly death when memory leaks consume > their swap space). If however there's no swap or a small swap, the OOM killer is given a chance to attack when it hits a runaway process Since there's no interactivity when the runaway process trashes swap, you end up wanting to reboot your box > So, stick by the swap partition being three times larger than the RAM - if > you have a machine with a gigabyte of RAM, you can certainly afford three > gigabytes of disk space, but you probably can't afford system crashes. This just gives a runaway process a lot longer before the OOM can even interrupt I/O and will probably result in you having a reboot Kernel 2.6 is used for the purpose of this discussion. For further discussion, please refer to the thread at fedora-devel-list (http://www.redhat.com/mailman/listinfo/fedora-devel-list), with topic "slow hard drives crushing interactivity" And for a test, install Fedora Core 3, fire up OpenOffice.org, right-click on a misspelled word, and watch it hit swap like never before. Wait, wait, and no OOM killer comes along (all thanks to swap, really). This was fixed in an update to OOo, so make sure this is via a stock FC-3 installation -- Colin Charles, [EMAIL PROTECTED] http://www.bytebot.net/ "First they ignore you, then they laugh at you, then they fight you, then you win." -- Mohandas Gandhi _______________________________________________ lpi-examdev mailing list lpi-examdev@lpi.org http://list.lpi.org/mailman/listinfo/lpi-examdev
