On Fri, Aug 21, 2009 at 12:22 PM, Jason Pfingstmann<no-re...@opensolaris.org> wrote: > Any thoughts on this? I don't see why it shouldn't work, but I've only been > tinkering with ZFS for 2 days now and this is all unexplored territory.
You shouldn't need to fake the size of your file-backed vdevs. If you plan on having 6 drives, create 6 files, each of them 1/6 of the total drive size. When you replace the all the files with the actual drives (or just with larger files) and export/import the pool, you'll have your 6 x 1.5T pool. For instance: 1) start with 6 x 250G on one drive. [6x250, 0 free] 2) Add second drive, create 3 x 500GB files [6x250, 0 free][0x0, 1.5T free] 3) Replace 1 vdev files in your pool with one of the new files [6x250, 0 free][3x500, 0 free] 4) Re-silver. 5) Repeat 3 & 4 for the other two files on the 2nd drive. 6) Delete the vdev files on the first drive that are no longer in use [3x250, 750 free][3x500, 0 free] 7) Create a new 500G file on the first drive and replace a vdev with it [3x250, 1x500, 250 free][3x500, 0 free] 8) Delete the vdev file you've replaced. [2x250, 1x500, 500 free][3x500, 0 free] 9) Repeat steps 7 & 8 [1x250, 2x500, 250 free][3x500, 0 free] 10) Fail the last 250G file out of the pool & delete the file. Your pool will be degraded. [2x500, 500 free][3x500, 0 free] 11) Create a new 500G file on the first drive and replace the missing vdev with it [3x500, 0 free][3x500, 0 free] You might be better off using slices/partitions so that the files don't become interleaved. You're going to have horrible performance due to excessive seeking regardless of what you do, too. If one of the drives fails, you'll still lose all your data. If you went to 3 drives you'd have some data protection using raidz2. You could continue to add drives one by one in this manner. For 3 drives, you'd use 750G slices, but 4 or 5 wouldn't be possible without major tom-foolery since the slice or file size would be > 0.5 * 1.5T. I'm too embarrassed to post my suggestion on how to work around that; it makes me feel dirty. In the long run, you're better off starting out with 6 drives. If you can't buy them all now, use 3x1.5 in a raidz and add another 3x1.5 raidz to your pool later. -B -- Brandon High : bh...@freaks.com _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
