fsck help please

[aerospace1028 at hotmail.com]

Hello,
This morning, when i powered on my machine, it failed to boot into archlinux.

The windows partition still loaded properly.

After concluding my morning business, I dug out my arch recovery CD and loaded into the live system.  I was able to mount both my root and home partitions, i was able to establish a chroot environment (although, I hadn't upgraded any packages over the weekend so it just demonstrated that it worked).

After some investigation, I determined with fsck that my root partition has a filesystem error.  My home partition came out clean.

I'm not overly knowledgeable about the filesystem or fsck.  I went through the interactive prompts, but selected the options that effectively changed nothing.

I wrote down some of the (hopefully) relevant output:


>> fsck /dev/sda4
...
[ 596.198487] Buffer I/O error on device sda4, logical block 8394655
Error reading block 107933, (Attempt to read block from filesystem resulted in short read) while getting next inode from scan.  Ignore error<y>? y
fore rewrite<y>? n
Pass 2: checking directory structure
Entry 'chcpu' in /sbin (262691) has deleted/unused node 272187.  Clear<y>? n
...
[ 1199.718449] Buffer I/O error on device sda4, logical bloc 8394655
Error reading block 1049331, (Attempt to read block from filesystem resulted in short read) while getting next inode from scan.  Ignore error<y>? y
force rewrite<y>? n
Entry 'chcpu' in /sbin (262691) has an incorrect filetype (was 1, should be 0).
fix<y>? n
...
Entry 'poweroff' in /sbin (262691) has deleted/unused inode 272188 clear <y>? n
Entry 'poweroff' in /sbin (262691) has incorrect filetype (was 1, should be 0).
fix<y>? n
Entry 'reboot' in /sbin (262691) has deleted/unused inode 272188. clear <y>? n
Entry 'reboot' in /sbin (262691) has incorrect filetype (was 1, should be 0).
fix<y>? n
Entry 'eog.mo' in /usr/share/locale/sv/LC_MESSAGES (263153) has deleted/unused inode 272179. clear <y>? n
...
Error reading block 1049331, (Attempt to read block from filesystem resulted in short read) while getting next inode from scan.  Ignore error<y>? y
force rewrite<y>? n
...



and it kept going on in this manner.  Eventually I said "no" to one of the "Error reading block ..." options and aborted the remainder of the check.


First after the "Error reading block ..." lines when it prompts "force rewrite" what is it rewriting?  Is this to be embraced or feared?

Second, on the deleted/unused inode prompts, What is it clearing (the inode itself, or the sign pointing to the inode)?

On the entries about the incorrect filetype, I presume it's actually safe to just trust fsck on this one?  Just double-checking so I don't put my system into an unrecoverable state.

Lastly, would the proper way of invoking fsck on the live-CD be 

fsck -a /dev/sda4


If I'm reading the manual correctly, that will autofix the "safe" options, correct?

Thanks in advance:-) 		 	   		  
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://listman.redhat.com/archives/blinux-list/attachments/20120910/d032dc78/attachment.htm>