> Also, at present I have 5x 1TB drives to use in my home server so I > plan to create a RAID-Z1 pool which will have my shares on it (Movies, > Music, Pictures etc). I then plan to increase this in sets of 5 (so > another 5x 1TB drives in Jan and nother 5 in Feb/March so that I can > avoid all disks being from the same batch). I did plan on creating > seperate zpoolz with each set of 5 drives; > > drives 1-5 volume0 zpool > drives 6-10 volume1 zpool > drives 11-15 volume2 zpool
Although this seems a good idea to start with, there are issues with it performance-wise. If you fill up VDEV0 (drives 1-5) and then attach VDEV1 (drives 6-10), new writes will still be initially striped across the two VDEVs, leading to a performance impact on writes. There is currently no way of balancing VDEV fills without manualy backup/restore or in-vdev copying the data from one place to another and then removing the original data. > so that I can sustain 3 simultaneous drives failures, as long as it's > one drive from each set. However I think this will mean each zpool > will have independant shares which I don't want. I have used this > guide - http://southbrain.com/south/tutorials/zpools.html - which says > you can combine zpools into a 'parent' zpool, but can this be done in > my scenario (staggered) as it looks like the child zpools have to be > created before the parent is done. So basically I'd need to be able > to; For the scheme to work as above, start with something like # zpool create mypool raidz1 c0t1d0 c0t2d0 c0t3d0 c2t4d0 c2t5d0 Later, you'll add the new vdev # zpool add mypool raidz1 c0t6d0 c0t7d0 c0t8d0 c2t9d0 c2t10d0 This will work as described above. However, I would do this somehow differently. Start off with, say, 6 1TB drives in RAIDz2 and set autoexpand=on on the pool (remember compression=on on the zfs pool fs too). # zpool create mypool raidz2 c0t1d0 c0t2d0 c0t3d0 c2t4d0 c2t5d0 c2t6d0 # zpool set autoexpand on mypool # zfs set compression=on mypool Compression is lzjb, and it won't compress much for audio or video, but then, won't hurt much either. When this starts to get somewhat close to a fill, get new, larger drives and replace the one by one with the older 1TB drives. Once all are replaced by larger, say 1,5TB drives, whops, your array is larger. This will scale better performance-wise and you won't need that many controllers. Also, with RAIDz2, you can lose any two drives. Vennlige hilsener / Best regards roy -- Roy Sigurd Karlsbakk (+47) 97542685 r...@karlsbakk.net http://blogg.karlsbakk.net/ -- I all pedagogikk er det essensielt at pensum presenteres intelligibelt. Det er et elementært imperativ for alle pedagoger å unngå eksessiv anvendelse av idiomer med fremmed opprinnelse. I de fleste tilfeller eksisterer adekvate og relevante synonymer på norsk. _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
