SVN access error after svnadmin dump

Look for the svn-hot-backup script. It should ship with subversion, and contains all the logic to do what you want, plus automagic rolling out of old backups. I have written the following wrapper script that uses svn-hot-backup to run as a nightly cronjob to backup a single server with multiple repositories, slightly modified to be generalized.

#!/bin/bash

#
# Dumps the svn repos to a file and backs it up
# to a local directory.

#Keeps the last 10 revisions
REPODIR="/var/repos"
BAKDIR="/data/backup/svn"
PROG="/usr/local/sbin/svn-hot-backup"
REPOLIST='repo1 repo2 repo3'

if [ ! -x "${PROG}" ]
then
        echo "svnbak: Could not execute \`${PROG}\`"
        exit 1
fi

for repo in ${REPOLIST}
do
    # Dump the database to a backup file
    echo "svnbak: Dumping subversion repository:  ${repo}"
    SVN_HOTBACKUP_NUM_BACKUPS=10 nice ${PROG} --archive-type=gz ${REPODIR}/${repo} ${BAKDIR}/${repo} &> /tmp/svnbak.$$

    if [ "$?" -eq "1" ]
    then
        echo "svnbak: Hot backup on '${repo}' failed with message:"
        /bin/cat /tmp/svnbak.$$
    fi

    /bin/rm /tmp/svnbak.$$
done

exit 0

It looks like your server version is too old (1.4.2). Your client, svnadmin, and repository are all at least 1.5, which is good, but I think your server itself needs to be at least 1.5 as well to support a "merge --reintegrate"