Hi,
I didn't think lvm2 had such a big performance hit?Did you try to ajust the read ahead with blockdev on the LV itself?
65Mb/s on the raid5 device 44Mb/s on the lv
# blockdev --setra XXXX /dev/sda (raid5 device, just for comparisson) # blockdev --setra XXXX /dev/vg/lv (lv)
Try some values for the readahead. On my system I use 2048.
No, I didn't hmm... man blockdev useful - new to me :) Not seen it on any googling to do with lvm.
I'll try this later when it's idle - thanks for the suggestion.
I do already have Read ahead sectors 100 in the lvdisplay
yet blockdev --getra /dev/video_vg/video_lv reports 256 (and, to be sure --getss says 512byte sectors)
Why is this different?
David _______________________________________________ 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/
