Yosemite Backup Question

[Shaunie1973]

Hi,

Stupid question. Myself and the wife both have separate (administrator) user accounts on the mac.

I assume that we would need to back up each account separately and that our respective administrator accounts won't back up the entire mac?

Thanks and regards,
Shaun

 

[Weaselboy]

Nope... just turn on TM from either account and turns it on for the entire drive and will backup both accounts.

 

[Shaunie1973]

Thanks

 

[maflynn]

TM is a fire and forget type of app that backs everything up on your hard drive (unless you choose to exclude some folders).

 

[Bomb Bloke]

Well... Nearly. It'll always skip Outlook databases, for example, regardless as to whether they're in use or what your exclusion settings are. If you happen to have one, it may pay to make a manual copy every now and then. In theory the databases can be rebuilt after a Time Machine restore, but in practise, there's an element of luck as to whether that process'll succeed.

Also skips your Trash, for what that's worth.

 

[maflynn]

It may skip the outlook DB because its locked or open. There's no code in TM to say skip MS Outlook. There has to be other issues that cause TM to avoid this.

As for trash, that makes sense, though I never really looked to see if trash is excluded. I suspect many of the cache files and swap files are also excluded.

 

[Bomb Bloke]

It doesn't matter whether the database is in use - Time Machine skips Outlook databases (regardless as to whether they're locked), and Outlook builds new ones after restoration of a user identity (eg, via system restore, or migration from backup).

I know what you're probably thinking about now, so don't take my word for it - hunt down a system with Outlook and Time Machine in use, ensure Outlook isn't running, trigger a backup, then search the result for the database file. How is this exclusion configured? I don't know, but nevertheless...

(Though it strikes me that this might've changed after, say, Outlook 2011. Couldn't say for sure. The linked article implies it's still a thing.)

What I do know is that prior to Outlook, Office for Mac offered Entourage - which also used a single database file, but stored all email-related data in it. Consider what happened when a user got an email - that database file changed, and Time Machine would include it in the next backup.

That is to say, on a regular basis Time Machine's hourly incremental backups would include the user's entire email collection. This led to backup drives being filled in fairly short periods of time.

Under Outlook, a single database file is still in use, and that file still gets quite large and changes often - but the actual email data is strewn across a set of much smaller files, the majority of which aren't affected when you eg get a new email. The database is no longer included in backups, solving the Entourage dilemma, and can be rebuilt in the event that a system restore is performed (by inspecting the separated email files, which of course are backed up).

The catch to all this is that the database rebuilding process is, in my somewhat limited experience, unreliable. I've seen it attempted on four different systems, and seen it succeed on only two of those - and without a working database, reading your emails becomes through Outlook becomes rather difficult.

Edit:

Mind you, I'd love to know where Time Machine's hidden exclusion list is kept. Presumably apps are able to alter it (just as they can tinker with the way Spotlight indexes certain files), and it'd be potentially handy to know what's on it.

 

[Shaunie1973]

Thanks for the detailed replies everyone.

OK, so, either of the two administrator accounts can create a back up and either will create a back up of the entire hard drive (i.e. both accounts).

This would mean that either account 1 or 2 could take a back up of the entire hard drive consisting of accounts 1 and 2.

Can account no 1 access the back up of account no2 or does the account need to be logged in to access its back up?

Am just wondering how the mrs would access her back up (account 2) if I got hit by a bus!

Thanks in advance.

 

[Bomb Bloke]

The permissions of the backed up files mirror those of the originals, no matter which account is logged in when the backups are performed.

Complete backups can also be performed while only non-admin accounts are logged in (assuming TM is already configured correctly). This is because Time Machine's "backupd" process isn't started by the active user - it's started by the OS, and fired up with root-level privileges (allowing it access to most anything and everything it wants to look at).

It's also worth noting that with a bit of know-how, the password on your account and the permissions system are only minor obstacles in getting at your personal files. They slow people down, sure, but if someone steals your whole computer that gives them a lot of time in which to play around.

If you specifically want to block people out, that's where the likes of FileVault comes into play. However, think twice before enabling it - if something goes wrong (eg, you forget your password, for starters!), you'll learn the hard way just how effective it is.