Lots of mapped out bad sectors cause trouble?
in [Storage]
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From: Franc Zabkar on 21 Oct 2009 01:19 On Tue, 20 Oct 2009 23:14:53 +1100, Grant <g_r_a_n_t_(a)bugsplatter.id.au> put finger to keyboard and composed: >On Tue, 20 Oct 2009 12:11:07 +0100, jack smith <invalid(a)mail.com> wrote: > >>AIUI ... a bad sector on an IDE hard drive gets labelled as unusable >>in the drive's map and a substitute sector is found. The user >>wouldn't know about it because this happens transparently. > >Apart from the etra time taken to seek to the reserve track and back? AIUI, spare sectors are available on each track. If all have been reallocated, then the next closest track is used. Pages 182 & 183 of the following manual discuss defect management in a Fujitsu drive: MPG3xxxAH DISK DRIVES PRODUCT MANUAL: http://www2.fcpa.fujitsu.com/sp_support/ext/desktop/manuals/mpg3xxxah-manual.pdf AFAIK, the reserved track dates back to MFM days. This track was used for diagnostic purposes. Nowadays there is a hidden System Area in the "negative" cyclinders. Among other things, it contains the bulk of the firmware and a P-list (factory defects) and a G-list (grown defects). I would think that these defect lists would be copied to RAM on power-up. - Franc Zabkar -- Please remove one 'i' from my address when replying by email.
From: holarchy on 21 Oct 2009 01:36
Franc Zabkar wrote: > On Tue, 20 Oct 2009 23:14:53 +1100, Grant > <g_r_a_n_t_(a)bugsplatter.id.au> put finger to keyboard and composed: > >> On Tue, 20 Oct 2009 12:11:07 +0100, jack smith <invalid(a)mail.com> >> wrote: >> >>> AIUI ... a bad sector on an IDE hard drive gets labelled as unusable >>> in the drive's map and a substitute sector is found. The user >>> wouldn't know about it because this happens transparently. >> >> Apart from the etra time taken to seek to the reserve track and back? > AIUI, spare sectors are available on each track. Not anymore. > If all have been reallocated, then the next closest track is used. > Pages 182 & 183 of the following manual discuss defect management in a Fujitsu drive: > MPG3xxxAH DISK DRIVES PRODUCT MANUAL: Thats a real dinosaur now. > http://www2.fcpa.fujitsu.com/sp_support/ext/desktop/manuals/mpg3xxxah-manual.pdf > AFAIK, the reserved track dates back to MFM days. Nope. They didnt even have spares at all. > This track was used for diagnostic purposes. Different matter entirely. > Nowadays there is a hidden System Area in the "negative" cyclinders. > Among other things, it contains the bulk of the firmware and a P-list > (factory defects) and a G-list (grown defects). I would think that > these defect lists would be copied to RAM on power-up. |