ubuntu_demon wrote: > Some bug reports about unnecessary disk activity. These bugs are > possible contributors to the Load_Cycle_Count issue. > > * the commit interval for the ext3 filesystem should be higher than 5 seconds > for laptop users > https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/160448 > > * ext3 partitions should be mounted with noatime or relatime for laptop users > https://bugs.launchpad.net/ubuntu/+source/util-linux/+bug/160450
These are actually two of the things that are tweaked by laptop-mode-tools when laptop mode is enabled. However, I should stress that they are not enough. To get longer periods without disk activity, the syncing behaviour given by /proc/sys/vm/laptop_mode is absolutely necessary. Here's why: if you have 5 programs that write to disk once every 10 minutes, that can cause either 5 spinups per 10 minutes (one every two minutes) or just one spinup, depending on how the disk I/O is spread out. The thing is that the expiry timeouts (the time that the system waits before writing a change back to disk) aren't synchronized, which means that even if you let everything cache its data for 10 minutes before writing to disk, this may well cause writes to disk every 30 seconds. When one thing triggers disk activity, there can be loads of other things waiting to be written, but which are _not_ written at that time because they haven't reached their expiry time yet: one change expires 20 seconds from now, one change expires in 70 seconds, one change expires in 100 seconds, etcetera. The trick of laptop_mode is that when one thing triggers disk activity, it syncs all of those other things to disk as well, thereby getting rid of _all_ changes that can possibly expire (and thus cause disk activity) in the near future. -- Hard drive spindown should be configurable https://bugs.launchpad.net/bugs/17216 You received this bug notification because you are a member of Ubuntu Bugs, which is a direct subscriber. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
