On Mon, Jun 10, 2002 at 12:07:22PM -0500, Ron Johnson wrote: > The problem with JBODs (just big ole disks, i.e. single disks)
JBOD = Just a Bunch Of Disks, i.e., several drives operating independently. A JBOD can be organized into a RAID, but doesn't have to be. > With RAID solutions, the read-write heads > will be in as many different places at once as you have disks. This is primarily a benefit in RAID0 or 5 configurations. RAID1 could benefit from it also, but a lot of RAID implementations are too stupid to take advantage of it. RAID4 loses some of this benefit due to the limitations of having all the parity data on a single disk. > Note, though, that since the CPU overhead from calculating RAID[45] > recovery blocks necessitates a caching controller. Otherwise, > write speeds will be slower. RAID1 is also typically slower since the write isn't considered to be complete until it has taken place on all disks (having read-write heads in many places helps reads and hurts writes). -- When we reduce our own liberties to stop terrorism, the terrorists have already won. - reverius Innocence is no protection when governments go bad. - Tom Swiss -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
