journal

ext3 re-enable internal journal

# Before: There is an ext3 filesystem with external journal (possible proken/unavailable)
# After: Filesystem uses internal journal again

# Step 1: Turn off (broken) external journal
tune2fs -0 ^has_journal /dev/someSdX

# Step 2: Enable internal journal
tune2fs -o journal_data -O has_journal /dev/someSdX

# Should work as before now
mount /mount/point/of/someSdX

Put ext3 journal on other (SSD) device (greatly improves write performance on hardware raid controllers)

# Before:
# /dev/someSdX is an ext3 data partition with internal (default) journal
# /dev/theSsdY is a partion of (max) 400MB on SSD
# Hint: Have all the Partitions aligned to MiB for optimal performance

# After:
# /dev/someSdX automatically uses external journal (idenfied by fs label)

# Turn off internal journal (takes some time)
tune2fs -O ^has_journal /dev/someSdX

# Create journal with speaking label
mke2fs -O journal_dev -L someSdX_journal /dev/theSsdY

# Make data partition use the journal device
tune2fs -o journal_data -j -J device=LABEL=someSdX_journal /dev/someSdX