** Summary changed: - insane default readahead settings on device and unused readahead setting in LVM + very sub-optimal default readahead settings on device and unused readahead setting in LVM
** Description changed: Binary package hint: lvm2 When you create an LV, the device ends up with a readahead of 256 512-byte sectors. A normal (non-LVM) device's readahead appears to default to 8192 512-byte sectors. This makes LVM FSs benchmark (and perform) very badly (our read rate dropped from 320M/s to 90M/s). To make matters worse, LVM has an internal 'read ahead sectors' variable which is apparently unused, but still displayed by e.g. lvdisplay which just adds to the confusion. - This is apparently a known issue upstream, but not considered a - priority: + This is apparently a known issue upstream: http://linux.msede.com/lvm_mlist/archive/2004/06/0108.html -- very sub-optimal default readahead settings on device and unused readahead setting in LVM https://bugs.launchpad.net/bugs/129488 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list [email protected] https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
