Greetings Have used zfs raidz for while and question rised is it possible to expand raidz with additional disks. Got answer pool yes but raidz "group" no. So very high level idea for you , maybe already know. And i''m not detail level expert of zfs so here might be "trivial" things for you. So could add operation enhanced so that it allow to add additional disks/devices to raidz. some criterias : larger or equal with current pool devices i assume tricky part is how to make that new device into use. how about every write is pointed to all devices and while read is only "previous" or brute force during add process write every file again using all devices. i know in NetApp Filers this allready works , so i think this is just finding way how to make it work in zfs raidz Thanks for your time This message posted from opensolaris.org
Just a data point -- our netapp filer actually creates additional raid groups that are added to the greater pool when you "add disks", much as zfs does now. They aren''t simply used to expand the one large raid group of the volume. I''ve been meaning to rebuild the whole thing to get use of the multiple parity disks back. Ours is a few years old and isn''t running the latest software rev, so maybe they''ve overcome this now, but thought I''d mention it. This message posted from opensolaris.org
> Just a data point -- our netapp filer actually creates additional raid > groups that are added to the greater pool when you "add disks", much > as zfs does now. They aren''t simply used to expand the one large raid > group of the volume. I''ve been meaning to rebuild the whole thing to > get use of the multiple parity disks back.That should be a setting, though. Not a limitation. Netapp will create a new raid group when all existing groups are at a particular point. That way the raid groups don''t become too large. Otherwise, it can expand the group. Today, ZFS doesn''t have that option.> Ours is a few years old and isn''t running the latest software rev, so > maybe they''ve overcome this now, but thought I''d mention it.This isn''t a new feature. Back in the "old days"(TM), there was only one volume and one raid group on a head. So adding disks to a volume required the raid group be expanded onto the disks. -- Darren Dunham ddunham at taos.com Senior Technical Consultant TAOS http://www.taos.com/ Got some Dr Pepper? San Francisco, CA bay area < This line left intentionally blank to confuse you. >
That''s the default, I think, but you can use ''vol add -g'' to add disks to an existing RAID group. This is fairly new functionality (V6.2 I think). ZFS will probably not take so long to add this feature. :-) This message posted from opensolaris.org