fixtm

#!/bin/bash
# Mount a network time machine sparsebunble who's claimed to have gotten corrupt and no longer backs up.
# I do this from a different mac than the one doing the backups.

if [[ $(whoami) != 'root' ]]; then
	echo "Must be run as root, dude."
    exit 1
fi

read -p 'Enter path of TimeMachine Server (i.e. 123.45.6.7/TimeMachine): ' TM_PATH
read -p 'Enter sparsebundle name: ' TM_NAME
read -p 'Enter Username: ' USERNAME
read -s -p 'Enter Password: ' PASSWORD

echo " "
echo "For encrypted backups you will be asked for the password to the disk after chflags is run"
echo " "
echo "---------------------"

MOUNT=/Volumes/TimeMachine
SPARSEBUNDLE="$MOUNT"/"$TM_NAME".sparsebundle
PLIST="$SPARSEBUNDLE"/com.apple.TimeMachine.MachineID.plist

echo "Mounting volume"
mkdir "$MOUNT"
mount_afp afp://"$USERNAME":"$PASSWORD"@"$TM_PATH" "$MOUNT"

echo "Changing file and folder flags. This can take some time..."
chflags -R nouchg "$SPARSEBUNDLE"

echo "Attaching sparse bundle"
DISK=`hdiutil attach -nomount -readwrite -noverify -noautofsck "$SPARSEBUNDLE" | grep Apple_HFS | cut -f 1`

echo "$DISK"

echo "Repairing volume. This WILL take some time..."
#diskutil repairVolume $DISK
/sbin/fsck_hfs -p "$DISK"
/sbin/fsck_hfs -fry "$DISK"

echo "Fixing Properties"
cp "$PLIST" "$PLIST.backup"
sed -e '/RecoveryBackupDeclinedDate/{N;d;}'   \
    -e '/VerificationState/{n;s/2/0/;}'       \
    "$PLIST.backup" \
    > "$PLIST"

echo "Unmounting volumes"
hdiutil detach /dev/"$DISK"
umount "$MOUNT"

exit 0

This has worked reasonably well for me. It's gathered from several different blog posts with steps guiding people how to do it. I should go and find those again to give credit.

When I was committing/sanitizing, I added the read for the IP/path to the Time Machine share. I was using a hardcoded value before, but this should work.

it also has trouble dismounting sometimes. :-/

diskutil unmountDisk $DISK
hdiutil detach /dev/$DISK

These might be better that the umount commands in the script.