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Technical Bulletin [Return to bulletin list]

Date: 2002-07-12

Description: Motor ext3  file system  becomes read-only.   

Affects: Flash-based filesystems using ext3 in Rocketcalc Redstone and
Atlas cluster nodes. NOTE: Rocketcalc clusters produced after April, 
2002 use the ext2 filesystem by default.

Summary: Motor ext3  file system  becomes read-only.   The  ext3 file
system used  on the flash storage  device on some  clusters can become
read-only due  to a problem  updating the journal. Read  this bulletin
for instructions to convert the  systems back to the default ext2 file
system.  The ext2 file system will not exhibit this problem.

Symptoms: The ext3 filesystem journal can become corrupted resulting in a
read-only file system.  Affected nodes will be unable  to update their
systems (for example, to add a user).

Diagnostic test:  Issue the command  "mount" to each node  and inspect
the results. If the root filesystem  (denoted by /) is mounted as type
ext2, disregard  this bulletin. If  the root filesystem is  mounted as
type  ext3 and is  flagged as  read-only (ro),  then proceed  with the
solution step below.

Solution:  If  any  one  node  exhibits  this  problem,  we  recommend
converting all nodes to the non-journaled ext2 filesystem. This can be
done without loss of data. Execute the following steps on each node to
convert affected filesystems:

1. Log  in  to  the node  as  the  root  user.   
2. Remount  the  root filesystem as read-only with the command
   mount -o  remount,ro / 
3. Convert  the filesystem to  ext2 with the command
   tune2fs -O ^has_journal /dev/discs/disc0/part1 
4. Reboot the node


File name File description
tune2fs Application used to modify ext2, ext3 filesystem parameters
ext3to2 Script to automate the solution step outlined above

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