Back up your hard drive

[muzzer]

time machine confuses me completely. does it mirror your main drive including deletions? i have a 3tb WD that i'm slowly putting all my itunes stuff on from an external drive but there's about 1tb and lots needs to be converted from aiff to mp3. none of the interfaces are really good. basically it's like having several cupboards of physical media and no time. plus ca change eh. then by the time you get it figured your hearing goes and you don't have enough time anyway. my dad has rooms full of vinyl and actually is only interested in the performance and the score not the recording. oh to know the works that well........

[Dave2002]

time machine confuses me completely. does it mirror your main drive including deletions? i have a 3tb WD that i'm slowly putting all my itunes stuff on from an external drive but there's about 1tb and lots needs to be converted from aiff to mp3. none of the interfaces are really good. basically it's like having several cupboards of physical media and no time. plus ca change eh. then by the time you get it figured your hearing goes and you don't have enough time anyway. my dad has rooms full of vinyl and actually is only interested in the performance and the score not the recording. oh to know the works that well........

The workings of Time Machine are not completely obvious, and as far as I can see Apple are not completely honest about what it does and how. However, for many people it will work reasonably well. The TM drive should be at least twice as big as the drive or partition(s) which are being backed up. There are several problems which may arise if the TM drive fills up. TM may simply delete a backup, which will probably be the one furthest back in time. It seems likely to me that data can be lost in that way, and having an algorithm like that does not necessarily place sensible values on the data which gets deleted. Another issue is whether the TM is transparent in what it does - if it deletes backups (and hence files) is it possible to find out what has gone, and thus see if there are other copies?

If you are the sort of person who creates very large transient amounts of data - for example in some media editing project - then it is very possible that storage will run out, and TM's strategy is almost certainly the wrong one to maintain data integrity.

Yes, TM does keep track of deletions, so it is possible to "undelete" files, providing the backup disc does not run out of space.

TM does take some of the work of maintaining backups away, and might also work well for multiple machines and users - for example using the Airport Time Capsule, and that can be helpful. However it may engender a false sense of safety, and to reduce the risk of problems further it is probably necessary to use another backup strategy as well, possibly using tools such as chronosync and super duper, or others which can create a bootable disc in order to maintain access to your machine. Backing up multiple machines, handy though that might be, raises the possibility that another user could effectively cause a wanted file to be deleted because the TM drive might run out of space.

I think TM does have some clever and good ideas, but without greater insight into what it actually does, or will do in difficult circumstances, I feel it is risky to rely on it as the sole method of "back up". It should make safeguarding data easier though, by reducing the need for frequent complete backups, and some people might find it really does do most of what they think they need.

It is important to consider what your data is worth to you. If it is worth a lot, and would be difficult to recover or replace, then it is a good idea to develop as rigorous a backup strategy as you can afford. On the other hand, some data may take up a lot of space, yet not really be that important to keep. Examples would be ripped DVDs of films which are commonly available, whereas some relatively small files may be much more valuable, and it could be disastrous if they are deleted.

[richardfinegold]

The workings of Time Machine are not completely obvious, and as far as I can see Apple are not completely honest about what it does and how. However, for many people it will work reasonably well. The TM drive should be at least twice as big as the drive or partition(s) which are being backed up. There are several problems which may arise if the TM drive fills up. TM may simply delete a backup, which will probably be the one furthest back in time. It seems likely to me that data can be lost in that way, and having an algorithm like that does not necessarily place sensible values on the data which gets deleted. Another issue is whether the TM is transparent in what it does - if it deletes backups (and hence files) is it possible to find out what has gone, and thus see if there are other copies?

If you are the sort of person who creates very large transient amounts of data - for example in some media editing project - then it is very possible that storage will run out, and TM's strategy is almost certainly the wrong one to maintain data integrity.

Yes, TM does keep track of deletions, so it is possible to "undelete" files, providing the backup disc does not run out of space.

TM does take some of the work of maintaining backups away, and might also work well for multiple machines and users - for example using the Airport Time Capsule, and that can be helpful. However it may engender a false sense of safety, and to reduce the risk of problems further it is probably necessary to use another backup strategy as well, possibly using tools such as chronosync and super duper, or others which can create a bootable disc in order to maintain access to your machine. Backing up multiple machines, handy though that might be, raises the possibility that another user could effectively cause a wanted file to be deleted because the TM drive might run out of space.

I think TM does have some clever and good ideas, but without greater insight into what it actually does, or will do in difficult circumstances, I feel it is risky to rely on it as the sole method of "back up". It should make safeguarding data easier though, by reducing the need for frequent complete backups, and some people might find it really does do most of what they think they need.

It is important to consider what your data is worth to you. If it is worth a lot, and would be difficult to recover or replace, then it is a good idea to develop as rigorous a backup strategy as you can afford. On the other hand, some data may take up a lot of space, yet not really be that important to keep. Examples would be ripped DVDs of films which are commonly available, whereas some relatively small files may be much more valuable, and it could be disastrous if they are deleted.

We used Time Machine at work, thinking we were backing up everything every day, automatically. Except when we checked after a couple ofweeks, nothing was backing up. We never did figure it out and junked it.

[MrGongGong]

I've used Time Machine very successfully for several years.
I wouldn't use it as the sole repository of vital data that I want to keep for ever
BUT
as a way of transferring all of your applications and data to a new hard drive or reformatted one it's excellent
the ability to go back to previous dates is also excellent
IT will start to delete old backups when the drive gets full BUT you DO know that this is happening

I think the more important thing is whether you really need to store huge amounts of old data anyway ?
Even for someone like me who does lots of big audio editing projects with big 'data footprints' (a 10 minute piece I made this year had a file of 10gb after a months work) i'm not sure that it's really necessary to always keep everything ?

I was very taken by the arguments in the book Delete: The Virtue of Forgetting in the Digital Age:

I'm a bit puzzled that someone 'at work' would use a backup for a couple of weeks without looking to see whether anything had been actually saved ? seems like a RTFM problem rather than one with Time Machine

Things that ARE vital to keep forever (you novel , operatic masterpiece etc ) are probably best kept in multiple places anyway (including the sealed registered post envelope hard copy that you can open with a flourish in court to prove that it's your work !)

[Dave2002]

IT will start to delete old backups when the drive gets full BUT you DO know that this is happening
!)

As far as I can see you do know - but after the event is useless!
In my case I was aware that something had happened, but what was lost - if anything - I had no way of finding out. Really appalling.

However, if the backup drive is big enough that this doesn't happen before some other backup method is invoked it should be fine.

I agree with MrGG that it shouldn't be used as the sole method of "backing up".

I am just a bit surprised that rfg didn't test it out - and it took several weeks to find that TM wasn't working properly. I installed and ran it on a machine which is being used elsewhere with a hard drive specifically bought for the purpose, and we checked that we could delete files, and then recover them, so as a tool for keeping track of sessions it's OK. There probably needs to be more awareness of how it works for anyone who is doing a lot of media work - though they'll most likely check it out. Most other people should find it works most of the time - but it is definitely a good idea to be aware of the possible problems before they come out and bite you, which could easily be years down the line and then unexpected.

[richardfinegold]

It wasn't my responsibility. When I asked to see some back ups after a few weeks, that is when the problem was discovered. Apparently the person overseeing this was getting some sort of message at the end of the day that the back ups were successful, but wasn't checking the database to verify.

[MrGongGong]

As far as I can see you do know - but after the event is useless!
In my case I was aware that something had happened, but what was lost - if anything - I had no way of finding out. Really appalling.

That's not my experience with Time Machine
What I have found is that when the TM disk gets full I get a message saying that this is what is going to happen before it does anything.

[Stunsworth]

That's not my experience with Time Machine
What I have found is that when the TM disk gets full I get a message saying that this is what is going to happen before it does anything.

Same here. It's a warning that you may like to consider buying a larger disk - or creating a raid set.

Remember that when it deletes an older backup all it means is that you can't retrieve files deleted before that date - or retrieve earlier versions of current files where the original was before that date. It will always keep a copy of everything on your current system.

I've only had to use it a couple of times - once when moving to a new Mac - and it's worked really well.

[MrGongGong]

Same here. It's a warning that you may like to consider buying a larger disk - or creating a raid set.

.

Indeed
but it is worth checking
I have had a Time Machine drive fail before

A suitable Haiku


Three things are certain
Death, taxes, and lost data.
Guess which has occurred