Christopher and Ross, Thanks for the tips. I will make some tests using md and check performance. Unfortunately I can't move the data to another LV to setup a new stripe value when a new PV is added. Thanks Lincoln On Mon, Mar 8, 2010 at 10:43 PM, Ross Walker <rswwalker at gmail.com> wrote: > On Mar 8, 2010, at 7:31 PM, Christopher Chan <christopher.chan at bradbury.edu.hk > > wrote: > >> On Tuesday, March 09, 2010 06:40 AM, Lincoln Zuljewic Silva wrote: >>> Hello list, >>> >>> I have a question about LVM. >>> >>> My server has five disks and I will use it to create a LVM >>> environment. >>> >>> I saw in the lvcreate man page that I can use the “-i” option to >>> set >>> the number of disks that I want to stripe the lvols, but this option >>> doesn’t exists in the “lvchange” option (in case I add new >>> disks to >>> the VG). >>> >>> I had in mind: create 10 lvols – “lvcreate -i5 -L 10G MyVG >>> /dev/MyVG/lvol[1-10]” and in the future, add more disks and incre >>> ate >>> the stripe value of the existing lvols. >> >> I would recommend md striping over lvm but then lvm is a bit more >> flexible on that score if you have disks of varying size. What are you >> using as your physical volumes? > > I actually like mdraid for raid1s then striping them with LVM for > raid10s and it has the added benefit of passing the config to the file > system during mkfs so it sets the chunk size and stripe width > appropriately. > >>> >>> Does anybody knows how to change the parameter “-i" of a lvol that >>> already exists? >> >> It appears to be fixed at creation time. Kinda hard to let you mess >> around with stripesize and what not after stuff has been laid out on >> the >> platters. > > Yeah, unfortunately you can't change the interleave of a LV. You need > to keep around 20% in reserve so when you add another PV you can > create a new LV with the new interleave and then copy or dump/restore > from the old LV to the new, delete the old LV, and repeat for the > other LVs in the group. Remember to start with your largest to your > smallest LVs. > > -Ross > > > _______________________________________________ > CentOS mailing list > CentOS at centos.org > http://lists.centos.org/mailman/listinfo/centos > -- Lincoln Zuljewic Silva More contact info.: http://www.system.adm.br/contact.php "How often must a question be asked before it’s considered a frequently asked question?"