On Tuesday 11 December 2012 05:57 PM, Alan McKinnon wrote: > On Tue, 11 Dec 2012 12:08:12 +0000 > Neil Bothwick <n...@digimed.co.uk> wrote: > >> On Tue, 11 Dec 2012 12:48:13 +0100, J. Roeleveld wrote: >> >>>> I'm using metadata version 1.2 for the raid0 array and the type is >>>> kernel based autodetect. >>> >>> Ouch, auto-detect does not work with metadata 1.2. >>> Please read the man-page section: >>> >>> Please rebuild the raid-device using v0.90 metadata and try again. >> >> I don't understand why your using RAID at all. LVM on top of RAID0 >> makes no sense to me when you can simply make each device a PV and >> add it to the VG. That's more flexible and easier to repair. >> >> > > Some folks like to do the striping in RAID, it's more controllable. 1st > block on this disk, 2nd block on that disk, 3rd block on first disk > again... > > Pooling LVM PVs into a VG is a huge gigantic basket of stuff where you > don't really get to control very much - LVM sticks data wherever it > wants to and you do little more than give some gentle hints (which > I strongly suspect are mostly ignored) > > But yes, in the usual case RAID-0 on LVM doesn't make much sense for > most folks. > > Personally, I prefer ZFS. This whole huge list of shit just goes away: > > disk partitions > partition types > disk labels > worrying about if my block size is right > worrying if my boundaries are correct > PVs as different from VGs and LVs > VGs as different from PVs and LVs > LVs as different from PVs and VGs > lvextend && growfs to make stuff bigger > umount && shrinkfs && lvreduce && growfs && mount to make stuff smaller > > I can now take a much simpler view of things: > > "I have these disks, use 'em. When I've figured out the actual quotas > and sizes I need, I'll let you know. Meanwhile just get on with it and > store my stuff in some reasonable fashion, 'mkay? kthankxbye! I have > real work to do." > > :-) > >
Exactly the reason why I wanted RAID0 and LVM in combination: more IOPS. ZFS looks very interesting, how stable is it? -- Nilesh Govindarajan http://nileshgr.com
