Seems strange on the surface. Would you mind posting the layout of each? ‘lvs -a -o +devices’ brassow > On Sep 13, 2017, at 8:53 AM, lejeczek <peljasz@yahoo.co.uk> wrote: > > hi boys, girls > > man page reads: -i ...This is equal to the number of physical volumes to scatter the logical volume data.... > I wonder, when I do not use -i while creating an LV with 10 phy devs. > > $ lvcreate -n raid0.A --type raid0 -I 16 -l 97%pv > > a dbench would show: > $ dbench -t 60 20 > ... > Throughput 112.309 MB/sec 20 clients 20 procs max_latency=719.409 ms > > Yet when I say: this many stripes: > > $ lvcreate -n raid0.A --type raid0 -I 16 -i 10 -l 97%pv > > dbench: > ... > Throughput 83.2822 MB/sec 20 clients 20 procs max_latency=816.027 ms > > And though the results would vary, xfs, a dbench for LV with no -i as an argument(which LVM chooses then to be 2) would always look better. > And I thought, as in the manual, always make stripes to go to all phy devices. > > Question - is there some "little" magic LVM does? And if yes then how/what it is? > many thanks, L. > > . > > _______________________________________________ > 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/ _______________________________________________ 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/
