Repairing a Transactional error on a Plone ZODB

NOTE: THIS PROCESS IS DESTRUCTIVE – USE AT YOUR OWN RISK.

A nightmare for any Plone administrator.. When restoring your server from a backup or after an unexpected server failure – You receive a message such as below when trying to start your instance:

ZODB.FileStorage.FileStorage.CorruptedTransactionError: /opt/plone/zinstance/var/filestorage/Data.fs data record exceeds transaction record at 20055859

This is never good – Though there is a process to repair your database. I would note, however, that this method is destructive and will simply “skip” the corrupted transaction – You will likely encounter error loss but some data is better than no data..

Download the below script to your server and update with the path of your zinstance directory – Run the script, enterring the corrupted record number in the script when prompted, it will go through and truncate your database, skipping the corrupted entry.

Fix-corrupted-data-fs.sh

#!/bin/sh
dir="/opt/plone/zinstance/var/"

# Browse to Directory
cd $dir
# Delete any current repair attempts
rm -f filestorage/Data.fs_ERR
# Copy the current, corrupted database to a temporary location
cp -p filestorage/Data.fs filestorage/Data.fs_ERR
# Delete the current database index
rm -f filestorage/Data.fs.index
#diagnostic run - Start plone
sudo -u plone_daemon ../bin/plonectl fg
echo ""
echo "................................................................"
echo "Copy the corrupted record location from the launch above:"
echo -n "put the number here:"
read CISLO
python<<_EOF
f = open("filestorage/Data.fs", "ab")
f.truncate($CISLO)
f.close()
_EOF
# Copy backup to new Database, skipping corrupted record location
dd if=filestorage/Data.fs_ERR of=filestorage/Data.fs.MISSING bs=1 skip=$CISLO
# Fix file permissions
chown -R plone_daemon:plone_group /opt/plone/zinstance/var/{blobstorage,filestorage}/
# Start Plone in Foreground mode again
sudo -u plone_daemon ../bin/plonectl fg

Hopefully the corrupted transaction record will not have caused too much Damage to your plone instance and you can now browse to your instance once more.