On Wed, May 09, 2012 at 05:14:00PM +0200, Helmut Hullen wrote: > Hallo, Hugo, > > Du meintest am 09.05.12: > > > DUP is two copies of each block, but it allows the two copies to > > live on the same device. It's done this because you started with a > > single device, and you can't do RAID-1 on one device. The first bit > > of metadata you write to it should automatically upgrade the DUP > > chunk to RAID-1. > > Ok. > > Sounds familiar - have you explained that to me many months ago? Probably. I tend to explain this kind of thing a lot to people. > > As to the spurious "upgrade" of single to RAID-0, I thought Ilya > > had stopped it doing that. What kernel version are you running? > > 3.2.9, self made. OK, I'm pretty sure that's too old -- it will "upgrade" single to RAID-0. You can probably turn it back to "single" using balance filters: # btrfs fi balance -dconvert=single /mountpoint (You may want to write at least a little data to the FS first -- balance has some slightly odd behaviour on empty filesystems). > I could test the message with 3.3.4, but not today (if it's only an > interpretation of always the same data). > > > Out of interest, why did you do the device adds separately, > > instead of just this? > > a) making the first 2 devices: I have tested both versions (one line > with 2 devices or 2 lines with 1 device); no big difference. > > But I had tested the option "-L" (labelling) too, and that makes shit > for the oneliner: both devices get the same label, and then "findfs" > finds none of them. Umm... Yes, of course both devices will get the same label -- you're labelling the filesystem, not the devices. (Didn't we have this argument some time ago?). I don't know what "findfs" is doing, that it can't find the filesystem by label: you may need to run "sync" after mkfs, possibly. > The really safe way would be: deleting this option for the "mkfs.btrfs" > command and only using > > btrfs fi label <device> [<newlabel>] ... except that it'd have to take a filesystem as parameter, not a device (see above). > b) third device: that's my usual test: > make a cluster of 2 deivces > fill them with data > add a third device > delete the smallest device What are you testing? And by "delete" do you mean "btrfs dev delete" or "pull the cable out"? Hugo. -- === Hugo Mills: hugo@... carfax.org.uk | darksatanic.net | lug.org.uk === PGP key: 515C238D from wwwkeys.eu.pgp.net or http://www.carfax.org.uk --- Quidquid latine dictum sit, altum videtur. ---
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