Date: Tue, 14 Dec 1999 04:00:34 -0800 (PST) From: dhesi@rahul.net (Rahul Dhesi) To: freebsd-stable@freebsd.org Subject: Re: how to rewrite the data field replaceable unit? Message-ID: <19991214120034.10BC021C@waltz.rahul.net> References: <freebsd-stable.199912140143.RAA02097@mass.cdrom.com>
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Mike Smith <msmith@freebsd.org> writes:
>> (da2:ahc0:0:2:0) Unrecovered read error - recommend rewrite the data field replaceable unit: 20 sks:80,a0
...
>That's two things, 'data' and 'field replaceable unit'. The FRU code
>tells you which part of the drive is failing - in this case the vendor
>code for the broken bit is '20'.
Thanks.
A suggestion to the Device Driver Gods: Please make error messages
understandable to the rest of us.
>...The drive will never forward a block if it
>involves losing the data that it can't get out of the block.
>Unrecovered read error -> return read error, do not forward block
Which makes sense. Thanks.
>In order to have the block forwarded (replaced), you need to put the drive
>in a situation where it can guarantee that no data loss will occur. The
>easiest way to do this is to work out which file contains the bad block,
>and copy it somewhere else, then delete the original....
This confuses me. Even if I have deleted the file that contains the bad
block, how is the disk hardware to know that?
>You can also unmount the drive and write to the block manually (write a
>small program that seeks to the bad block and then writes to it).
This seems promising. If I succeed in writing to that bad block,
and later cause a read from it, and a recoverable error occurs during
the read, the disk will likely remap the block.
One more question:
fsck reports some unreadable block numbers. What is the block size
assumed by fsck when it reports that block n is bad? Is it the same
as the block size of the filesystem (in this case 8192 bytes)?
And if so, then to rewrite the block, would I seek to
(block no. * 8192) and then write 8192 bytes?
And yet another question:
When 'badsect' reports that a bad block cannot be attached because it is
in a a non-data area, what does this mean?
--
Rahul Dhesi <dhesi@spams.r.us.com>
See my UUNET spam mini-faq at:
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