Date: Sat, 9 Oct 2004 04:51:26 -0600 (MDT) From: Doug Russell <drussell@saturn-tech.com> To: Sergey Babkin <babkin@bellatlantic.net> Cc: John Von Essen <john@essenz.com> Subject: Re: hacking SCO.... Message-ID: <20041009044403.P39589-100000@mxb.saturn-tech.com> In-Reply-To: <41672E84.9DE09887@bellatlantic.net>
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On Fri, 8 Oct 2004, Sergey Babkin wrote: > Try to use the "Verify" menu from the Adaptec BIOS. It finds and tries > to re-map the bad sectors (it tries to preserve data during this too, > unless the sector is completely unreadable). The verify commands issued by the BIOS are virtually useless compared to the type of tests done my sformat. If you enable automatic read re-allocation, it is almost the same as simply reading your whole disk with dd. > > I do the full 14 pattern tests before I put a SCSI disk in service. > > When a disk starts losing blocks like this, usually they only multiply > over time. The best thing you can do is replace the disk and > move the data before you lost more of it. NO! Not necessarily! If a disk has simply grown a few new defects since it was new, it does not necessarily mean it is going to die. I have many disks that had minor bad spots on them that weren't even always found by the factory format routines, or had appeared since (due to transport, debris in the HDA, poor holding power for the magnetic fields in some area, etc). If the drive passes through a few full patern tests without problems and doesn't continue to grow new defects, it is likely just fine. I've got all kinds of old SCSI disks that were 'discarded' due to errors. Only a couple are truly dead... the rest have been running for years with no problems after making a real grown defect list from the pattern tests. This is something I learned many many years ago when running my old Miniscribe 3650s on a Perstor high density controller. It formated the drives to 31 sectors per track instead of 17. Hard on the disks, and the media, but a good drive, after being properly tested, would run flawlessly for years being hammered 24/7 on BBS machines. Got 78 megs per drive instead of 42.whatever it was. :) Later...... <Doug>
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