[EMAIL PROTECTED] wrote: > What are the current best practices with regards to swap partitions? > Is it better to create one big, or several smaller swap partitions? > Is the rule of thumb still RAM*2 for the total size?
For a server I turn off Linux memory overcommit. This avoids ever having the out-of-memory killer run and kill random unrelated processes. Especially in a multiuser environment or in an enterprise level environment this is very important. But turning off overcommit means that the rule of RAM*2 comes back into play. Search the web for linux kernel out of memory killer and memory overcommit and you will find much discussion about it. Start here. http://lwn.net/Articles/104179/ http://linux-mm.org/OverCommitAccounting http://www.redhat.com/magazine/001nov04/features/vm/ I recommend trying following in order to disable linux kernel memory overcommit. This will cause malloc() to fail when memory is exhausted. (The default is that malloc() and fork() will always pass.) This should avoid the linux kernel out of memory killer from becoming active and killing random processes on the system. This will cause only the programs that are asking for more memory to fail. This is the traditional Unix memory model. I recommend configuring servers that need reliable operation this way. sudo sysctl -w vm.overcommit_memory=2 HOWEVER! If you do not have enough virtual memory / swap space at the time that you activate this configuration then it may cause your system to be unable to fork() and malloc() starting at that moment. If the system becomes unusable due to fork failure you may need to reboot. You must have enough virtual memory configured to handle all of your expected simultaneously running applications. Be careful that you can reboot your server remotely if you do not have physical access. Since the above 'sysctl' test is a temporary configuration a reboot will reset to the default allowing memory overcommit and enabling the out of memory killer if the system runs out of memory and needs a reboot to be saved. If you decide that is a good configuration to keep it memory overcommit disabled then it may be configured in /etc/sysctl.conf to be set to off at boot time. This is what I recommend when there is enough virtual memory available. Bob -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
