Yeah, this threw me. A 3 disk RAID-Z2 doesn't make sense, because at a redundancy level, RAID-Z2 looks like RAID 6. That is, there are 2 levels of
parity for the data. Out of 3 disks, the equivalent of 2 disks will be used to store redundancy (parity) data and only 1 disk equivalent will store actual data. This is what others might term a "degenerate case of 3-way mirroring", except with a lot more computational overhead since we're performing 2 parity calculations. I'm curious what the purpose of creating a 3 disk RAID-Z2 pool is/was? (For my own personal edification. Maybe there is something for me to learn from this example.) Aside: Does ZFS actually create the pool as a 3-way mirror, given that this configuration is effectively the same? This is a question for any of the ZFS team who may be reading but I'm curious now. On Mon, Mar 15, 2010 at 10:38, Michael Hassey <mhas...@gmail.com> wrote: > Sorry if this is too basic - > > So I have a single zpool in addition to the rpool, called xpool. > > NAME SIZE USED AVAIL CAP HEALTH ALTROOT > rpool 136G 109G 27.5G 79% ONLINE - > xpool 408G 171G 237G 42% ONLINE - > > I have 408 in the pool, am using 171 leaving me 237 GB. > > The pool is built up as; > > pool: xpool > state: ONLINE > scrub: none requested > config: > > NAME STATE READ WRITE CKSUM > xpool ONLINE 0 0 0 > raidz2 ONLINE 0 0 0 > c8t1d0 ONLINE 0 0 0 > c8t2d0 ONLINE 0 0 0 > c8t3d0 ONLINE 0 0 0 > > errors: No known data errors > > > But - and here is the question - > > Creating file systems on it, and the file systems in play report only 76GB > of space free.... > > <<<<SNIP FROM ZFS LIST>>>>>>> > > xpool/zones/logserver/ROOT/zbe 975M 76.4G 975M legacy > xpool/zones/openxsrvr 2.22G 76.4G 21.9K > /export/zones/openxsrvr > xpool/zones/openxsrvr/ROOT 2.22G 76.4G 18.9K legacy > xpool/zones/openxsrvr/ROOT/zbe 2.22G 76.4G 2.22G legacy > xpool/zones/puggles 241M 76.4G 21.9K > /export/zones/puggles > xpool/zones/puggles/ROOT 241M 76.4G 18.9K legacy > xpool/zones/puggles/ROOT/zbe 241M 76.4G 241M legacy > xpool/zones/reposerver 299M 76.4G 21.9K > /export/zones/reposerver > > > So my question is, where is the space from xpool being used? or is it? > > > Thanks for reading. > > Mike. > -- > This message posted from opensolaris.org > _______________________________________________ > zfs-discuss mailing list > zfs-discuss@opensolaris.org > http://mail.opensolaris.org/mailman/listinfo/zfs-discuss > -- "You can choose your friends, you can choose the deals." - Equity Private "If Linux is faster, it's a Solaris bug." - Phil Harman Blog - http://whatderass.blogspot.com/ Twitter - @khyron4eva
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