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Why Time Machine is not for me, and maybe not for you either...

N

neoben

macrumors member
Original poster
Sep 4, 2007
64
1
I loved the idea of time machine, but it has a fatal flaw that makes it unusable for me, and maybe others too...

Large files that have small changes often will get entirely backed-up every hour.

So, if you have a >1GB Entourage mail database, a 5GB Parallels virtual drive, a large Aperture database, etc.... this files are likely to be backed up every hour, which may mean almost constant disk access!

The fix for this is easy. All TM needs is to have an option to not only backup or not backup a file, but also to backup 'when changed' or backup 'on a schedule'.

That way, most files can be backed-up 'when changed', but files like Entourage DB or a Parallels HD can be backed-up on schedule, such as once per day.

Until that feature makes it in, I'll have to stick with SuperDuper (hoping it's updated soon..!)

Anyone else find this issue to be a deal-breaker for TM?

Best,

Ben
---------------------------------------------------------
neo-fight.tv - {The Weekly Technology Podcast}
 
I have just excluded my big this such as parallels from TM as I have a full clone as well. Hopefully people like paralles will change how the files are stored so that TM only backs up the changes.
 
Yes, one could exlclude the big files from the backup, but then you need to have two backup systems...

Such a shame...

Best,

Ben

---------------------------------------------------------
neo-fight.tv - {The Weekly Technology Podcast}
 
This is where ZFS comes in...........the file will be backed up fully the first time.....then when backed up again only the changed blocks will be backed up i.e. make a 2Mb change to a 10Gb file and only around 2Mbish will be backed up....so you can have loads of versions at the cost of very little space....

This is where time machine (and quite a few other things) are heading. With ZFS's help of course.
 
As for aperture I've excluded this from my TM, and use the vaults instead. However surely the aperture library contains individual files (if you open package contents) - so does it really have to backup the entire thing if something's changed?
 
Time Machine shows why sometimes it's better to have individual files instead of a huge database file that appears as one on the computer. Parallels disk images are one thing, but email databases would benefit from single files. Hopefully Microsoft and other companies will develop for Spotlight/Time Machine and optimize their files for such programs. In the meanwhile, it'd be nice to see Time Machine adopt ZFS as it's file system like others have mentioned in this thread.
 
mrfrosty said:
This is where ZFS comes in...........the file will be backed up fully the first time.....then when backed up again only the changed blocks will be backed up i.e. make a 2Mb change to a 10Gb file and only around 2Mbish will be backed up....so you can have loads of versions at the cost of very little space....

This is where time machine (and quite a few other things) are heading. With ZFS's help of course.
Click to expand...

Too bad ZFS is still vaporware.
 
I would like the option (and i'm sure its not for everyone) to say "here's 5Gb on my internal drive to save version changes until I reconnect to my BUD". When I reconnect, these files get uploaded to the BUD, TM's history is refreshed with whats been happening while i've been away, and the 5Gb buffer is cleared. From what I understand, TM uses Spotlight's file referencing to recognize whats in a file and what changes have been made. I'm sure it would know when I change a local file without having to look at my TM BUD to know that something has changed.

There may need to be some advanced selections here such as "yes/no delete older version when i save new changes", "yes/no only backup files under 10Mb", "save local images for 1 day/1 week/1 month" etc. Im sure it can't b too hard.
 
So Time Machine backs up the entire file every time it's changed? Not just the changes? That stinks. I thought it just did the changes.

So I need a bigger hard drive than the actual hard drive on my laptop?
 
neoben said:
I loved the idea of time machine, but it has a fatal flaw that makes it unusable for me, and maybe others too...

Large files that have small changes often will get entirely backed-up every hour.

So, if you have a >1GB Entourage mail database, a 5GB Parallels virtual drive, a large Aperture database, etc.... this files are likely to be backed up every hour, which may mean almost constant disk access!
Click to expand...

Are you 100% sure about this? I'm not saying you're wrong, but it seems slightly crazy of Apple to design a feature like this, particularly as there's already software out there such as Super Duper that can do smart updates and just back up what's changed (without the need for ZFS).

I backup my hard drive pretty much everyday and on average it takes 8-9 minutes (160GB drive). I'd imagine if I did it every hour it would take even less.
 
I dont need some automated program to back up my data. I have it off. And forcing you to use an external is a horrible idea too.
 
Ariez said:
I dont need some automated program to back up my data. I have it off.
Click to expand...

Well that's fine for you, but I think most users will find it to be nice and convenient.

And forcing you to use an external is a horrible idea too.
Click to expand...

How is it a bad idea? Part of the point of using Time Machine is so you can have a back-up when you need it. By having your back-up on an external drive (which most prudent people do anyways) you encourage people to protect their data and at the same time make it possible for them to view all previous versions of the file. For normal users, and even for pro users, Time Machine offers good benefits.
 
Apple.com said:
For the initial backup, Time Machine copies the entire contents of the computer to your backup drive. It copies every file exactly (without compression), skipping caches and other files that aren’t required to restore your Mac to its original state.

Following the initial backup, Time Machine makes only incremental backups — copying just the files that have changed since the previous backup. Time Machine creates links to any unchanged files, so when you travel back in time you see the entire contents of your Mac on a given day.
Click to expand...

Hmmm. I see where you're coming from. If the file, for example your Entourage file, is changed, then it "copies the file" so if it was several gigs it would have to re-copy several gigs.

However, I was under the impression that it simply backs up the data within that file that has changed. So, if 98% of the file is the same there's no need to re-copy, it just incrementally backs up the 2% that has changed? That's how I understand it but that could be a misunderstanding of the way it works.

As said though, it would seem crazy to enable multiple GB backups every hour. It just wouldn't work, would it? Particularly in a professional environment where there's lots going on to lots of different and multi-GB files...

Time machine page on Apple.com
 
AlBDamned said:
Hmmm. I see where you're coming from. If the file, for example your Entourage file, is changed, then it "copies the file" so if it was several gigs it would have to re-copy several gigs.

However, I was under the impression that it simply backs up the data within that file that has changed. So, if 98% of the file is the same there's no need to re-copy, it just incrementally backs up the 2% that has changed? That's how I understand it but that could be a misunderstanding of the way it works.

As said though, it would seem crazy to enable multiple GB backups every hour. It just wouldn't work, would it? Particularly in a professional environment where there's lots going on to lots of different and multi-GB files...

Time machine page on Apple.com
Click to expand...

Part of the reason it copies the entire file over again is because you can restore to any one of the previous versions you've saved. I think the best way to work around the storage problem would be to simply change the frequency from once per hour to once per day.
 
CalBoy said:
Part of the reason it copies the entire file over again is because you can restore to any one of the previous versions you've saved.
Click to expand...

That doesn't have any relevance though. You're still losing that complete file the next time it copies over it, so either way, when you restore it's putting two separate chunks of data together, marrying the bulk of what hasn't changed with the tiny bit that has?
 
AlBDamned said:
That doesn't have any relevance though. You're still losing that complete file the next time it copies over it, so either way, when you restore it's putting two separate chunks of data together, marrying the bulk of what hasn't changed with the tiny bit that has?
Click to expand...

Sorry, I don't know what you mean with the text that's been bolded. As far as I understand Time Machine to work, you can go back to any of the previous versions that have been backed up, no matter how small or minor the differences. I assumed the way it worked was:

Hour 1: Saved presentation: 10MB
Hour 2: Edited presentation: 12MB
Hour 3: Edited presentation: 15MB
Total size on back up disk: 37MB

Thus, if I choose to, I can go back to my first 10MB presentation, or the second 12MB one, etc.
 
CalBoy said:
Sorry, I don't know what you mean with the text that's been bolded. As far as I understand Time Machine to work, you can go back to any of the previous versions that have been backed up, no matter how small or minor the differences. I assumed the way it worked was:

Hour 1: Saved presentation: 10MB
Hour 2: Edited presentation: 12MB
Hour 3: Edited presentation: 15MB
Total size on back up disk: 37MB

Thus, if I choose to, I can go back to my first 10MB presentation, or the second 12MB one, etc.
Click to expand...

Ok so this is where I'm getting it wrong. I was thinking it simply backed up the changed data, not backed up every different file to have multiple versions of that file. I guess if you're constantly editing and changing large (5-10 gig) files you're going to fill up a back-up drive pretty fast so yeah, if so it seems to be a pretty flawed system at present...
 
AlBDamned said:
Ok so this is where I'm getting it wrong. I was thinking it simply backed up the changed data, not backed up every different file to have multiple versions of that file. I guess if you're constantly editing and changing large (5-10 gig) files you're going to fill up a back-up drive pretty fast so yeah, if so it seems to be a pretty flawed system at present...
Click to expand...

Yeah, with large files it can eat up storage space really quickly. However, I think there's a way to change how often you want particular files/folders to be updated.

If not, then I know you can omit certain files for sure. It would then be up to you to back them up on your own.
 
Before installing Leopard I setup 2 external drives. One of them is 320GB for Time Machine, and the other I setup with 2 partitions. One partition for doing manual backups to by simply copying things manually to it that I want to have duplicates of, and the other a Project partition. Both are on the ignore list for Time Machine. It keeps things really simple.

Videos get saved to Project, Turbo.264 saves to Project, Tag info gets changed on Project, and then once something is ready to be added to iTunes, I copy it over to the main hard drive, let TM back it up, and delete the original from Project.

It's really quite simple. :)
 
This CAN'T be correct - at least not entirely anyway, because of one program: iPhoto!

Apple changed it so iPhoto's library is now just a single file (that you can obviously go into to see the individual photos), and mine is currently at 7.67GB.

Apple WOULD NOT change it to a single file if they were going to bring out a Time Machine that would back up several GBs every time you took a few pictures!

Edit:

Have a poke around in the Backups.backupdb folder on the root of your Time Machine drive, the first backup Time Machine did is only about 130MB for me, the others are quite larger (couldn't be bothered for it to figure out the sizes...)
 
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