I see that the wm servers use RAID 0 quite a bit, and wondered why not JBOD?
Does RAID 0 perform better, or was there some other reason?
http://en.wikipedia.org/wiki/Redundant_array_of_independent_disks#RAID_0
--- Ursprüngliche Nachricht ---
I see that the wm servers use RAID 0 quite a bit, and wondered why not JBOD?
Does RAID 0 perform better, or was there some other reason?
Striping data over multiple disks usually allows equal utilization of all disks in a RAID0. Usually, there are some hot spots in a database, where most write and read operations happen, and some colder areas, for example very old revisions. Since our database grows continuously, hot spots usually are at the end of the database file. With concatenation this would be on only one disk, while other disks were idle.
JeLuF
wikitech-l@lists.wikimedia.org