On Wednesday 22 of February 2012 09:56:27 Xavier Nicollet wrote: > Le 21 February 2012 ? 07:54, Hugo Mills a écrit: > > Some time ago, I proposed the following scheme: > > <n>C<m>S<p>P > > > > where n is the number of copies (suffixed by C), m is the number of > > > > stripes for that data (suffixed by S), and p is the number of parity > > blocks (suffixed by P). Values of zero are omitted. > > > > So btrfs's RAID-1 would be 2C, RAID-0 would be 1CnS, RAID-5 would > > > > be 1CnS1P, and RAID-6 would be 1CnS2P. DUP would need a special > > indicator to show that it wasn't redundant in the face of a whole-disk > > failure: 2CN > > Seems clear. However, is the S really relevant ? > It would be simpler without it, wouldn't it ?
It depends how striping will be implemented. Generally it provides information on how much spindles is the data using. With static configuration it will be useless, but when you start changing number of drives in set then it's necessary to know if you're not under- or over- utilising the disks. -- Hubert Kario QBS - Quality Business Software 02-656 Warszawa, ul. Ksawerów 30/85 tel. +48 (22) 646-61-51, 646-74-24 www.qbs.com.pl -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
