Have you read http://wiki.apache.org/cassandra/CassandraHardware ?
On Tue, May 31, 2011 at 7:47 AM, Erik Forsberg <forsb...@opera.com> wrote: > Hi! > > I'm considering setting up a small (4-6 nodes) Cassandra cluster on > machines that each have 3x2TB disks. There's no hardware RAID in the > machine, and if there were, it could only stripe single disks > together, not parts of disks. > > I'm planning RF=2 (or higher). > > I'm pondering what the best disk configuration is. Two alternatives: > > 1) Make small partition on first disk for Linux installation and commit > log. Use Linux' software RAID0 to stripe the remaining space on disk1 > + the two remaining disks into one large XFS partition. > > 2) Make small partition on first disk for Linux installation and commit > log. Mount rest of disk 1 as /var/cassandra1, then disk2 > as /var/cassandra2 and disk3 as /var/cassandra3. > > Is it unwise to put the commit log on the same physical disk as some of > the data? I guess it could impact write performance, but maybe it's bad > from a data consistency point of view? > > How does Cassandra handle replacement of a bad disk in the two > alternatives? With option 1) I guess there's risk of files being > corrupt. With option 2) they will simply be missing after replacing the > disk with a new one. > > With option 2) I guess I'm limiting the size of the total amount of > data in the largest CF at compaction to, hmm.. the free space on the > disk with most free space, correct? > > Comments welcome! > > Thanks, > \EF > -- > Erik Forsberg <forsb...@opera.com> > Developer, Opera Software - http://www.opera.com/ > -- Jonathan Ellis Project Chair, Apache Cassandra co-founder of DataStax, the source for professional Cassandra support http://www.datastax.com
