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Message ID: 2197     Entry time: Fri Nov 6 18:13:34 2009
Author: josephb 
Type: Update 
Category: Computers 
Subject: Megatron woes 

I have removed the RFM card from Megatron and left it (along with all the other cables and electronics) on the trolly in front of the 1Y9 rack.

Megatron proceeded to boot normally up until it started loading Centos 5.  During the linux boot process it checks the file systems.  At this point we have an error:


/dev/VolGroup00/LogVol00 contains a file system with errors, check forced

Error reading block 28901403 (Attempt to read block from filesystem resulted short read) while doing inode scan.

/dev/VolGroup00/LogVol00 Unexpected Inconsistency; RUN fsck MANUALLY


So I ran fsck manually, to see if I get some more information.  fsck reports back it can't read block 28901403 (due to a short read), and asks if you want to ignore(y)?.  I ignore (by hitting space), and unfortunately touch it an additional time.  The next question it asks is force rewrite(y)?  So I apparently forced a rewrite of that block.  On further ignores (but no forced rewrites) I continue seeing short read errors at 28901404, *40, *41,*71, *512, *513, etc.  So not totally continugous.  Each iteration takes about 5-10 seconds.  At this point I reboot, but the same problem happens again, although it starts 28901404 instead of 28901403.  So apparently the force re-write fixed something, but I don't know if this is the best way of going about this.  I just wondering if there's any other tricks I can try before I just start rewriting random blocks on the hard drive.  I also don't know how widespread this problem is and how long it might take to complete (if its a large swath of the hard drive and its take 10 seconds for each block that wrong, it might take a while).

So for the moment, megatron is not functional.  Hopefully I can get some advice from Alex on Monday (or from anyone else who wants to chime in).  It may wind up being easiest to just wipe the drive and re-install real time linux, but I'm no expert at that.


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