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Apple's "Time Machine" Now For Linux... Sort Of
deander2 writes "Apple's 'Time Machine' is cool, but I use Linux, not MacOSX. So here is a Linux implementation (built off of rsync, of course). No fancy OpenGL, but quite functional none-the-less."
There's already been work on a Linux Time Machine, just not ready for prime time yet: TimeVault.
I just drag my important files onto an external drive.
The whole point is that you don't have to do that, it happens automatically.
AND it catches all the files that you didn't think were important, but are.
AND it lets you roll the system back to the state it was in at any given time in the past (hence "time machine").
AND it takes care of any problems that can happen during backup (like "disk full", "power failure", etc.).
Can we get a "-1 Wrong" moderation option?
What Leopard also did was add file system support for hard links to directories, so that backups from different points in time could be easily presented as complete volume images without any need for a special backup file format, yet still share storage for unchanged files.
(Find files that have been altered from last update -> Copy Said files to alternate drive in directory with the date as a name, make note of files that have deleted)
:|
Trivialising the technical underpinnings of Time Machine is unwise, and plays right into the hands of those who say Apple is all about show and lacks substance. In fact, the way Time Machine knows what files have been modified is really quite elegant and shouldn't be underplayed. I shan't go into the details of it all here, but if you are interested, see the relevant page of John Siracusa's excellent review of 10.5 over at Ars Technica.
In the meantime, you might like to consider learning how to spell.
Yeah. There's more to Time Machine than just a one-off backup of your data. TM aggregates changes and you can roll back to any point in time.
Think of it as CVS. It tages backup times but actually only copies new data as it's checked in.
Also, TM is not confined to the Finder per say. if you're in Address Book and lost a contact, type in the filter string to locate it. Still can't find it? Right there from Address Book, hit Time Machine and Address Book will be served with backed-up address book data, filtering on the fly, as you go back in time until you find what you've been looking for.
Same thing for anything spotlight-able.
So, yeah, it's got a pretty interface, but TM goes way beyon just file/backup management.
The tiny difference here is that apples FSEvents is basically a daemon following the fsevents device (OS X equivalent of inotify) all the time keeping a log (directory level, as to not bog everything up with a lot of small changes), so the backup app does not have to run in the background all the time. It also notices when the disk changed while not mounted in OS X (In which case it only tells you _that_ the disk changed, I believe. You still have to figure out what changed, exactly yourself).
Unless you can produce a link or some debugger output or something, I'm gonna go ahead and trust ArsTechnica more than I trust you.
Cretin - a powerful and flexible CD reencoder
from the website:
http://www.ext3cow.com/
Ext3cow is an open-source, versioning file system based on ext3. It provides a time-shifting interface that allows a real-time and continuous view of the past. This allows users to access their file system as it appeared at any point in time.
Ext3cow was designed as a platform for regulatory compliance, and has been used to implement secure deletion, authenticated encryption, and incremental authentication. See the publications page for more details.
Some advantages of ext3cow:
1.
It does not pollute the name space with named versions
2.
It has low storage and performance overhead
3.
It is totally modular, requiring no changes to kernel or VFS interfaces
You can't be ahead of the curve, if you're stuck in a loop.
...Also, TM is not confined to the Finder per say. if you're in Address Book and lost a contact, type in the filter string to locate it. Still... It's PER SE, goddamnit! And it means "intrinsically!" You saying "TM is not confined to the Finder per se" would imply that either it IS somehow confined to finder (but not intrinsically) or you just like to use big-person words you don't understand. Please! Think about what you're saying!Except rsnapshot uses rsync, which must rescan the filesystem. With Time Machine, the FSEvents daemon makes that unnecessary in the common case. Also, Time Machine uses hard links to directories.
That's not true. Read the link I posted above. rsync can create hard links, through the magical --link-dest option. This means that you never need to do full backups, or worry about keeping track of several versions.
/etc/cron.{daily,weekly,monthly}/.
/etc/snapshot/include.txt`
/usr/bin/awk 'substr($0,length($0),
You can set up rsync to do hourly, daily, weekly, and monthly backups, all taking up minimal (and I mean minimal) disk space, using hard links.
All you have to do is rm -rf your oldest directory of each kind (hourly daily, weekly, monthly) every time you run.
Heck, I'll even give you the BASH script I use to do this. Call it via cron: e.g. snapshot daily
#!/bin/bash
# This script makes a snapshot of several directories using rsync.
# Version 0.5, Rob Bos, September 8, 2002
# Modified by Pausanias August 2004
# This script is released under the terms of the
# GNU General Public License, version 2.0.
# run "hourly" from a crontab; run daily, weekly, and monthly from
[ -z "$1" ] && echo syntax: $0 snapshottype baselinesnapshottype && exit 1
type=$1 # hourly, daily, monthly snapshot?
logfile=/var/log/snapshot.log
backuproot=/Volumes/Sutton/ibackup
backup=`cat
excludefile=/etc/snapshot/exclude.txt
echo `date` >> $logfile
[ ! -e "$backuproot" ] && echo "$backuproot not mounted." >> $logfile && exit 1
# Assume that the baseline snapshot type is daily unless otherwise
# specified.
if [ "f$2" == "f" ]; then
basetype="daily"
else
basetype="$2"
fi
# if you run every two hours, make it 12, every hour, 24, etc. try to span the entire day.
# The below setting runs 8 times a day (every three hours), keeps 7 days, 4 weeks, and 12 months
# of backup.
hourlymax=8
dailymax=10
weeklymax=5
monthlymax=8
# This simplifies things down below so I can use $max to delete
# the overrotated snapshot, as well as $hourlymax/$dailymax to do
# rotation checks.
[ $type == "hourly" ] && max=hourlymax
[ $type == "daily" ] && max=dailymax
[ $type == "weekly" ] && max=weeklymax
[ $type == "monthly" ] && max=monthlymax
# Rotate the current list of backups, if we can.
if [ -d $backuproot/$type.1 ]; then
oldest=`ls -dt $backuproot/$type.* | tail -n 1 | sed 's/^.*\.//'`
echo Oldest is $type.$oldest >> $logfile 2>&1
for i in `/usr/local/bin/seq $oldest 1 -1`; do
mv $backuproot/$type.$i $backuproot/$type.$(( i + 1 ))
done
linkopt="--link-dest=$backuproot/$type.2"
else
linkopt=""
fi
if [ "$type" == "$basetype" ]; then
rsync -xva $linkopt --safe-links --delete --delete-excluded --exclude-from=$excludefile $backup $backuproot/$type.1/ >> $logfile 2>&1
elif [ "$type" == "daily" ]; then
[ -d $backuproot/hourly.$hourlymax ] && mv $backuproot/hourly.$hourlymax $backuproot/daily.1
elif [ "$type" == "weekly" ]; then
[ -d $backuproot/daily.$dailymax ] && mv $backuproot/daily.$dailymax $backuproot/weekly.1
elif [ "$type" == "monthly" ]; then
[ -d $backuproot/weekly.$weeklymax ] && mv $backuproot/weekly.$weeklymax $backuproot/monthly.1
fi