lemons_terry@emc.com writes: > http://www.tldp.org/HOWTO/LVM-HOWTO/mapmode.html > <http://www.tldp.org/HOWTO/LVM-HOWTO/mapmode.html> states: > > "In LVM 2, striped LVs can be extended by concatenating another set of > devices onto the end of the first set. So you can get into a situation where > your LV is a 2 stripe set concatenated with a linear set concatenated with a > 4 stripe set. Are you confused yet?" > > As a matter of fact, I am! > > I need to start with a 2 disk (therefore, 2 stripe) logical volume, that I > later extend with 2 more disks. How is this done? In lvm2 you simply create the lv with a stripe size of 2, then later when you want to extend it, you lvextend it with a stripe size of 2. The reason this is explained in so much detail is that in LVM1, you could not extend a striped set past its original PVs. In LVM2, the original striped set can be extended to the end of the original PVs, and any additional PVs become a striped set that is tacked on to the end (concatenated). Maybe an ACSII picture can help ;) Original striped volumes: ___ ___ | 1 | | 2 | | 3 | | 4 | |_5_| |_6_| After adding two more disks and lvextending: ___ ___ ___ ___ | 1 | | 2 | | 7 | | 8 | | 3 | | 4 | | 9 | | 10| |_5_| |_6_| |_11| |_12| So you have 2 sets of striped segments (with 2 stripes each), concatenated together. It does *not* remap all the striping so you have 1 set of striped segments (with 4 stripes each). Is that any clearer? -- AJ Lewis Voice: 612-638-0500 Red Hat Inc. E-Mail: alewis@redhat.com 720 Washington Ave. SE, Suite 200 Minneapolis, MN 55414 Current GPG fingerprint = D9F8 EDCE 4242 855F A03D 9B63 F50C 54A8 578C 8715 Grab the key at: http://people.redhat.com/alewis/gpg.html or one of the many keyservers out there... _______________________________________________ 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/
