> On Thu, 25 Jan 2001 11:37:27 +0100 "Aley Keprt" <[EMAIL PROTECTED]> wrote: > > > > > > > On Thu, 25 Jan 2001 09:08:50 +0100 "Aley Keprt" <[EMAIL PROTECTED]> > > wrote: > > > > But why you still rely on "disk crash = all data are lost" ? > > > > > > This is the case with RAID0 (lost = lost from the RAID). > > > > > > -Frode > > > > I see the problem is that I don't see disk crash is equal to "disk is > > completely lost". > > If you have some errors on a disk drive, and you can still use the rest of > > it, your RAID0 still works. > > Or not? > > This is not a disk crash. This is a sector error. ALL disk have sector > errors. In the old days, ie. pre 1986 or thereabouts, these used to be > marked as 'bad blocks' in a block map on the disk. This was done from > the factory. If you wanted to keep this map up to date, you had to > run some software to check this for you. > > Disk nowadays still have block errors. However, some percentage of the > disk is now reserved for this purpose. Whenever the disk detects a > "bad block" it marks it as bad and substitute it with a block from the > reserved area.
Okay. I though "disk crash" refers to any error on disk drive, since if disk doesn't crash, it runs well. And when it doesn't run well, something bad must happened. > If there is data on such a bad block, the disk usually detects the > fault early enought to salvage the data. But sometimes you loose the data > in such a bad block. This happens VERY rarely in my experience, I have > only heard of this, not experience it myself. I suspected this once, but > I used another controller and the disk worked nicely evre since (6 years > now). > > When I talk about a crash I mean a crash which can not be repaired with > conventional means. This can be a physical crash where the only way is > to send it to a profesional compnay (www.ibas.com) or it might be a > crash in the filesystem. A format or a low-level format ususlly solves > this. > > -Frode The question is if this definition is only yours, or the standard one. I have never distinguished between several different disk errors. i.e. either disk is in good condition or not If not (i.e. at least one bad sector appeared), I consider this disk unusable and try to keep away from it ;-) Aley
