"Jonah H. Harris" <[EMAIL PROTECTED]> writes: > On 5/29/07, Luke Lonergan <[EMAIL PROTECTED]> wrote: >> AFAIK you can't RAID1 more than two drives, so the above doesn't make sense >> to me.
Sure you can. In fact it's a very common backup strategy. You build a three-way mirror and then when it comes time to back it up you break it into a two-way mirror and back up the orphaned array at your leisure. When it's done you re-add it and rebuild the degraded array. Good raid controllers can rebuild the array at low priority squeezing in the reads in idle cycles. I don't think you normally do it for performance though since there's more to be gained by using larger stripes. In theory you should get the same boost on reads as widening your stripes but of course you get no benefit on writes. And I'm not sure raid controllers optimize raid1 accesses well in practice either. -- Gregory Stark EnterpriseDB http://www.enterprisedb.com ---------------------------(end of broadcast)--------------------------- TIP 7: You can help support the PostgreSQL project by donating at http://www.postgresql.org/about/donate
