DragonFly users List (threaded) for 2009-01
Re: RAID 1 or Hammer
On Jan 12, 2009, at 9:13 PM, Gergo Szakal wrote:
"nntp.dragonflybsd.org" <firstname.lastname@example.org> wrote in message 496b8121$0$881$415eb37d@crater_reader.dragonflybsd.org">news:496b8121$0$881$415eb37d@crater_reader.dragonflybsd.org
I'm curious if RAID 1 (mirroring) really helps to protect data
loss. Of course if a whole disk "dies", RAID 1 has the advantage that
I have an identical copy. But what happens if only a sector of one
contains bad data. How can the RAID controller decide which is the
correct sector? Or would the disk detect such a case and return an
When the controller will try to perform an I/O operation it will fail
on the faulty disk (the disk with the bad sector). As a result the
controller will be able to decide which is the correct sector.
IMHO RAID provides redundancy and higher data availability while
provides data safety by by backups. Having a non-0 RAID array is not
equal to data
safety IMHO. Only backups can provide that.
Just my very own 0.02 though.