Everything went surprisingly smooth, with only a handful of special cases to deal with, and a nice log file to catch those anomalous instances. New accounts were not created, but instead orphaned and chowned to a dummy user account.
Notice that I am using read into a while loop instead of a for loop from find. This is a good way to handle filenames with spaces and special characters.
migrate-www.sh:
#!/bin/bash
### uncomment afterwards and do not re-run
#exit 1
### sync files from old to new host
mkdir /www-old
rsync -aq old_server:/www/data /www-old/
### copy old auth files and manually edit groups
rsync -aq root@old_server:/etc/passwd /www-old/passwd.old
rsync -aq root@old_server:/etc/group /www-old/group.old
cat /www-old/group.old >> /etc/group
vim /etc/group
### map old UIDs to new UIDs
#for I in `find /www-old/data`; do
find /www-old/data | while read I; do
echo -n "$I"
OUID=`ls -ndl "$I" | cut -d ' ' -f 3`
echo -n " OUID $OUID"
OLOGIN=`grep "\:x\:$OUID\:" /www-old/passwd.old | cut -d ':' -f 1`
echo -n " OLOGIN $OLOGIN"
NUID=`grep ^$OLOGIN\: /etc/passwd | cut -d ':' -f 3`
if grep -q ^$OLOGIN\: /etc/passwd; then
echo " NUID $NUID"
chown $NUID "$I"
else
# chown jack(1209) files to john(3572)
case "$NUID" in
"1209" )
echo " ADOPT 3572"
chown 3572 "$I"
;;
# own jill(921) to jane(372)
"921" )
echo " ADOPT 372"
chown 372 "$I"
;;
*)
echo " ORPHAN 499"
chown 499 "$I"
;;
esac
fi
done
### special case perm changes
# adopt to bob
chown -R 5432 /www-old/data/projectA
# new GID for group 432 is 1487
find /www-old/data -gid 432 -exec chown :1487 {} \;
Execute the scipt and redirect all output to a log file for later analysis:
# chmod +x migrate-www.sh
# ./migrate-www.sh > migrate-www.log 2>&1 &
# tail -F migrate-www.log
