Bad sectors are detected on write. There are 5 wires going to each of the read/write heads on my disk drives. I think each head can read after write in 1 pass. My specs say it re-maps on write failure and read failure. Both are optional. But, I don't know if this is normal or not. My disks are Seagate ST118202LC, 10,000 RPM, 18 Gig SCSI. Guy -----Original Message----- From: linux-raid-owner@xxxxxxxxxxxxxxx [mailto:linux-raid-owner@xxxxxxxxxxxxxxx] On Behalf Of Mario Holbe Sent: Sunday, January 09, 2005 5:10 AM To: linux-raid@xxxxxxxxxxxxxxx Subject: Re: Spares and partitioning huge disks maarten <maarten@xxxxxxxxxxxx> wrote: > Do you mean SCSI ones do ? If so, I thought the firmware intelligence between I don't think, SCSI ones do so. However, I don't know many SCSI drives and thus I limited my sentence to IDE drives :) > 1. If you write to it and that fails the drive will allocate a spare sector. As I said earlier: >> 1. would require some verify-operation, so I'm not sure if this >> is done at all in the wild. A verify would take time and therefore I think, this is not done. Btw: *if* it would be done, write speed to disks should be read-speed/2 or smaller, but usually it isn't. > From that we [should be] able to conclude that if you get a write failure > that the drive ran out of spare sectors. (is that a fact, or not??) Yes, this is a fact. > So basically what you're saying is that reallocation _only_ happens on > _writes_ ? Hm. Maybe, I don't know... What I'm saying is: bad sectors are _only_ detected on reads and reallocations only happen on writes, yes. > Or maybe that isn't a problem since the disk gets kicked, and afterwards > during resync the reallocation pays off. Yeah. That must be it. :-) This is what I said, yes :) regards, Mario -- () Ascii Ribbon Campaign /\ Support plain text e-mail - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
