[besson3c]

VSC:

Microsoft Corporation


Anybody know exactly how Time Machine is implemented, and how this differs from existing implementations? Or, is it basically the same feature with a different UI?

[besson3c]

Damn, forgot the question mark in my subject... sorry!

[Ganesha]

Both TM and VSC, work on the single file level which allows you to selectively restore single files, directories or volumes.

But, TM also tracks data for users in a non-file centric model.

Example, you recently cleaned your address book of 100 contacts. You realize you need one contact back.

VSC (depending on how the data is stored) would do one of two things. One is to restore all 100 contacts. The other is to restore the file containing the single contact, but require the user to manually reintegrate the data, into their address book.

Time machine, will selective restore the single contact without any need to manually integrate the data. This is because Address Book, (and any application that wants to), tells TM how to manage and restore address book data.

[besson3c]

Originally Posted by Ganesha 

Both TM and VSC, work on the single file level which allows you to selectively restore single files, directories or volumes.

But, TM also tracks data for users in a non-file centric model.

Example, you recently cleaned your address book of 100 contacts. You realize you need one contact back.

VSC (depending on how the data is stored) would do one of two things. One is to restore all 100 contacts. The other is to restore the file containing the single contact, but require the user to manually reintegrate the data, into their address book.

Time machine, will selective restore the single contact without any need to manually integrate the data. This is because Address Book, (and any application that wants to), tells TM how to manage and restore address book data.

Very slick!

So, how are these changes tracked? I can understand tracking the differences between text files, that is easy, but what about binary data? Do these tools have to keep entire copies of your binaries?

If not, I would imagine that this revision control must exist at a pretty low level. Do you know how it works?

[macintologist]

You probably need an external hard drive to back everything up, likely a size larger than the one you're backing up in the first.

[besson3c]

Originally Posted by macintologist 

You probably need an external hard drive to back everything up, likely a size larger than the one you're backing up in the first.

If the backup volume (whether it would be an external HD, NFS mount point, SSHfs mount, whatever) was only tracking file revisions and not simply keeping copy of files, this wouldn't be the case, would it?

[mduell]

VSC can be accessed over the network; not so sure about Time Machine.

Originally Posted by Ganesha 

Time machine, will selective restore the single contact without any need to manually integrate the data. This is because Address Book, (and any application that wants to), tells TM how to manage and restore address book data.

TM integration doesn't just happen because the application "wants to"; it requires code changes by the developer of the application.

[Mithras]

One advantage of VSC is that it doesn't mandate the use of a separate backup disk -- it can save reference points on the same volume, which is nice for the casual user. (Or even the careless non-casual user, as in Larry Osterman's case).

Though, the difference in UI shouldn't be underestimated. This is the crappy mechanism for restoring old versions in VSC:

[JKT]

Originally Posted by Mithras 

One advantage of VSC is that it doesn't mandate the use of a separate backup disk -- it can save reference points on the same volume, which is nice for the casual user.

Actually, I would argue the opposite - the fact that TM does mandate the use of a separate backup disk is probably the most significant positive about it as people who currently don't have any external back up of all their valuable data (and there are far too many) might be encouraged to finally do the sensible thing and get that external or second drive that everybody should have.

A backup to the same disk is almost as worthless as no back up at all, casual user or not.

[mduell]

I think both, requiring an additional backup disk and not supporting an additional backup disk, are half baked. Requiring it leaves you screwed when you're on the road, but supporting it encourages you to eliminate the single point of failure.

[besson3c]

Originally Posted by mduell 

I think both, requiring an additional backup disk and not supporting an additional backup disk, are half baked. Requiring it leaves you screwed when you're on the road, but supporting it encourages you to eliminate the single point of failure.

Which is exactly why network backups make a lot of sense, providing you have access to the network, and providing you have a reasonable amount of bandwidth. It's too bad there are still bottlenecks with the latter.

[OreoCookie]

Originally Posted by mduell 

I think both, requiring an additional backup disk and not supporting an additional backup disk, are half baked. Requiring it leaves you screwed when you're on the road, but supporting it encourages you to eliminate the single point of failure.

I agree.
However, even more importantly, the feature has to be easy to use. I haven't laid a finger on Vista yet, but from the looks of it, MS' implementation seems to be difficult to use and many (if not most) users won't even know about it.

IMHO an external backup disk is far preferable, so users won't even get tempted to rely on one harddrive.

So if Time Machine is as easy to use as it seems to be, people like my father will finally have a working backup solution. (I've set up a FreeBSD server, but my brother inadvertently formatted the backup drive … so it's no longer usable )

[Person Man]

Originally Posted by besson3c 

Which is exactly why network backups make a lot of sense, providing you have access to the network, and providing you have a reasonable amount of bandwidth. It's too bad there are still bottlenecks with the latter.

You also need the storage space, too.

Apple's new Airport lets you have a USB disk drive attached to it... sort of a "NAS for the everyday person" as it were... perhaps that would be supported for Time Machine, too.

[besson3c]

All of this talk about an external drive is great, but as a laptop user that likes to move around, I don't want to maintain my connection to an external drive.

My wireless network backup in my home LAN to my development FreeBSD server is awesome. I think that perhaps the way to go for people like me is with backup network appliances. The only problem is getting a DNS entry setup to follow a dynamic IP for when you are outside of your LAN.

[OreoCookie]

Originally Posted by besson3c 

All of this talk about an external drive is great, but as a laptop user that likes to move around, I don't want to maintain my connection to an external drive.

Yes, it is. On the other hand, I doubt many people would be aware of the fact that they'd need an external drive to be on the safe side.

Originally Posted by besson3c 

The only problem is getting a DNS entry setup to follow a dynamic IP for when you are outside of your LAN.

Dyndns.org?
Works perfectly for my parents and me.

[Simon]

Originally Posted by OreoCookie 

Dyndns.org?
Works perfectly for my parents and me.

Ditto here.

[Catfish_Man]

Originally Posted by mduell 

TM integration doesn't just happen because the application "wants to"; it requires code changes by the developer of the application.

The changes necessary are used in other parts of the OS though, so any app that takes advantage of certain Leopard functionality will integrate with Time Machine automatically.

In other news, I hate NDAs. I want to be able to explain all this stuff in detail, to clear up the confusion.

[mduell]

Originally Posted by Catfish_Man 

The changes necessary are used in other parts of the OS though, so any app that takes advantage of certain Leopard functionality will integrate with Time Machine automatically.

In other news, I hate NDAs. I want to be able to explain all this stuff in detail, to clear up the confusion.

I'm guessing you meant Core Data, even if you can't confirm it.

But my point was that you're not going to get any tight integration between, say, Microsoft Office and Time Machine; it will be the same all-or-nothing bringing files back that VSC offers.

[Catfish_Man]

Originally Posted by mduell 

I'm guessing you meant Core Data, even if you can't confirm it.

Negative. Also, I believe Apple has likely taken care of MS Office, much like they did with spotlight importing. Haven't checked though.

[kcmac]

Not that I would want to backup my info on my internal hard drive, but won't Time Machine allow for that? You can buy an iMac with a huge hard drive (for most users) of 500 GB or even 750 GB. That would be plenty of space for most people to have their backup on the same hard drive.

Again, not saying I would do that.

Plus, I picture more people getting used to external hard drives to hold more music, movies, photos, etc to use with AppleTV or FrontRow. And with the ZFS thing, these harddrives will just automagically combine with each other, no setup required. (Right?)

[Don Pickett]

FWIW, my plan is to get one of the LaCie ethernet external drives, plug it into my router, and use that as a backup for both my machines. Backing up onto the same drive as the data you're backing up is asking for trouble.

[Chuckit]

Originally Posted by kcmac 

Not that I would want to backup my info on my internal hard drive, but won't Time Machine allow for that?

Not from the information that's been released. (Then again, logic doesn't allow it either. Copying data onto the same drive is not backing up!)

[Mithras]

Originally Posted by Catfish_Man 

Negative. Also, I believe Apple has likely taken care of MS Office, much like they did with spotlight importing. Haven't checked though.

It seems to me that Entourage would be the biggest problem, since (last I checked, anyway) it still stores all emails, attachments, appointments etc. into one giant database file. Having that single file backed up every day will eat up backup space pretty quickly.

[Brass]

Originally Posted by Chuckit 

Copying data onto the same drive is not backing up!

It is backing up, it just isn't a very good backup. Remember there's more to backups than disaster recovery, or hardware/software faults.

Copying data to the same disk is great for 99.999% of human-error related problems.

Having said all that, I'd suggest that nobody should every rely on this type of backup alone. There should always be a backup to an external medium as well, of course.

But copying to the same disk is still a backup... just not a safe one.

[besson3c]

Originally Posted by Brass 

It is backing up, it just isn't a very good backup. Remember there's more to backups than disaster recovery, or hardware/software faults.

Copying data to the same disk is great for 99.999% of human-error related problems.

Having said all that, I'd suggest that nobody should every rely on this type of backup alone. There should always be a backup to an external medium as well, of course.

But copying to the same disk is still a backup... just not a safe one.

I would say that copying to the same disk is more appropriately called "revision control", but maybe that's just a techie that is highly accurate but not really part of our nomenclature...

[Brass]

Originally Posted by besson3c 

I would say that copying to the same disk is more appropriately called "revision control", but maybe that's just a techie that is highly accurate but not really part of our nomenclature...

And I'd say that revision control is a form of backup.

But I agree... it's all just sematics.

[mitchell_pgh]

My plan is to wait until I see what Leopard has before doing anything.

TM sounds too good to be true.