On 11/28/2009 11:52 AM, Michael Guntsche wrote: > I am currently running the 2.6.32-rc8 kernel with lvm2 version 2.02.54-1 > on debian unstable. > Since my root is on LVM as well I use an initramfs for booting. The > setup I have consists of 5 disks in a RAID-5 with one PV on top of it. > Now for my problem. The md device correctly sets the read-ahead to 4096. > If I understand correctly lvm should get this value and set the > read-ahead on the LVs accordingly. This is not working correctly for > all my LVs. Hi, the logic is simple here - if readahead is set to auto, it should inherit value from underlying device for all LVs on that PV - if there is explicitly set value in metadata, it should always use that (you can switch back to auto by specifying -r auto) (striped volumes calculate readahead differently, but it is not the case here) There was similar issue - caused by not updated lvm in initrd (or with different lvm.conf there) - all volumes activated in initramdisk had different readahead value set - please check this. Also Check default value of readahed in lvm.conf in activation section. (See also https://bugzilla.redhat.com/show_bug.cgi?id=473273 ) If you still see that some volume is activated wrongly, please send debug output of lvchange -a y -vvvv <LV>, blockdev --getra <PV> > For testing purposes I took one LV (home) offline and back online again > > lvchange -an;lvchange -ay > > After that the readahead was set correctly to 4096. I am not sure what's > happening here. I would understand a problem with getting the values > automatically but right now they are saved in the metadata but are still > set to 256. Check which lvm activated it first - it seems that it uses old default or old version of lvm. Milan -- mbroz@redhat.com _______________________________________________ linux-lvm mailing list linux-lvm@redhat.com https://www.redhat.com/mailman/listinfo/linux-lvm read the LVM HOW-TO at http://tldp.org/HOWTO/LVM-HOWTO/
