On Thu, Dec 10, 2009 at 05:00:34PM -0500, nixlists wrote: > On Thu, Dec 10, 2009 at 3:37 PM, Marco Peereboom <sl...@peereboom.us> wrote: > >> So in what cases does softraid degrade the mirror then, other than > >> pulling the disk out? > > > > When an I/O fails. > > > >> How is hardware mirror raid different? > > > > It isn't. > > > >> > >> Thanks. > > Does this mean there's little advantage of hardware mirror raid over software? > So software mirror raid increases chances of data corruption while decreasing > the chances of downtime. True for hardware as well?
There are pro and cons to both solutions. Pick what makes sense in your scenario. > Hmmm. I've used hardware raid cards for mirrors that have the verify function. > It would be interesting to know how and what those cards do. They read the data to make sure the disk is working. If one disk is failed they can rebuild that block from the remaining disk provided that the remaining disk isn't corrupt or broken too. They assume that the data that was read is accurate; if it isn't you are SOL. They either don't detect or ignore blocks that are different because they can not know which one is accurate (if any). Verify for RAID 1 is mostly marketing fluff.
