Two Library Folders and Time Machine

I have two library folders on my Mac Pro running Yosemite 10.10. One is in the root of my first HD, the second is in the Users folder. See picture attached.

The one in the Users folder is a lot smaller and contains a lot less files than the other. Time Machine has been set to exclude in the Users folder in its entirety. I back up all my docs, pictures and so on on a second and forth HD, so it is redundant to have TM back them up too.

What purpose does the Library folder in Users serve and can it be deleted?

Thanks,

Peter B.

NO it cannot be deleted. Each user has their own Library folder.
That's where all your prefs and other important settings/stuff are.
The one at the root of the drive is the System Library.
That's the way it's supposed to be.

Hi Craig,

OK so each user, and there is only one, me, has their own library folder. To back up the one in the users folder, I need to exclude all the other user folders in my TM setup. I have dozens of them. It would be simple if TM worked the other way and allowed folders for back up to be added rather than excluded. Then one could pick and choose.

Maybe I can find an alternative to TM, it seems to be not well thought out. Probably written by someone who does not use it, or who has a very simple setup without many folders and files, yes? My user folder has 152,818 items in it and occupies 455.86 GB. That is a lot of bananas for TM to back up for me. I back them all to two separate drives anyway.

I always thought that Apple computers were supposed to be easy, LOL.

Thanks,

Peter B.

For the time being at least until I can find an alternate, I have excluded from TM all but a few exceptions in my User folder. The exceptions include the Library folder.

Lets see how TM handles that arrangement.

Peter B.

TM is designed to back up your entire system so that when the boot drive fails, once the replacement is installed, you can simply reinstall the OS and then recover your personal files/settings/data back to just like it was before it failed. In fact, if you have a bootable USB drive or USB memory stick, you don't even have to reinstall the OS, it will be restored along with everything else.

Doing what you are doing, excluding files and folders, is actually working AGAINST TM and making it harder on yourself. Just give TM plenty of room and let it rip, backing up everything. Note that TM will do a complete backup once, then shift to incremental backups of just the files that changed after that, so it will grow in space use very slowly. I have a 500GB file backed up to a 1TB drive. I currently has backups going back to January 2014, and has just hit 822GB of data. So it's taken 18 months to use up just 160% of the drive it's backing up. That isn't bad, IMHO.

The general principle is to give the TM drive twice the size of the drive it's backing up. It will then manage to that space just fine, and will start deleting the oldest backups when it needs space.

As for other products, you can look at Carbon Copy Cloner or SuperDuper!, both of which will clone your drives, can be programmed for when to run, and will allow you to select what to include and exclude. They can even hold historical copies for you of files they clone, if you want that capability. TM does that natively, btw.

One more thing: OS X is a multi-user system, so that's why user libraries. I would suggest you create at least one other admin user, even if you never use it. When/if your own account gets hammered by something, it's nice to be able to log in as a separate user and see what is going on and to have to gain control of the system again. All it costs is a little disk space for the basic files.

@mb300e You seem to be concerned about having multiple copies of your User/Library folder in the Time Machine backup. I think you may not be aware of exactly the way it works and why it is designed that way.

When you do a Time Machine backup the initial backup takes quite a bit of time because it copies all the files on the art drive unless they have been excluded. The next backup doesn't take long nor does it take up much space because Time Machine does the following:
1. Any files created or modified since the last backup are backed up.
2. Any files that are unchanged are not backed up again. Time Machine simply creates a pointer to the location of the file. If the file is modified it gets put into the list of files to back up.

This method of operation gives you an archive of past work/system changes. That's an important distinction from a normal backup. Here's how that matters. Lets assume you've been writing the next great novel and have written 10 pages.You make a backup of your work every day.

One day you decide that page 10 is horrible and make major changes and make a backup.. A few days from now you decide the original page 10 is better. With a normal backup you can't get that page back because it has been overwritten by the subsequent backups. With Time Machine each time a file is changed that file is copied but the original is not overwritten. Time Machine only starts deleting things when the drive is getting too full.

@mb300e

TM, it seems to be not well thought out. Probably written by someone who does not use it,

Click to expand...

From the excellent replies above, you can now see that Time Machine was well thought out, well designed and is ideally suited for people who use it.

One additional comment about cloning backups, I don't think mentioned, is that they are bootable. TM is not. Most folks who care passionately about not losing data, use both methods (TM and cloning software).

Ian

I have added the USER folder back in TM but have excluded all the folders that contain files such as pictures, docs etc. These are backed up elsewhere. Now TM will backup user folders such as Library.

Also I did not need TM to create a huge backup file and take up all of the available 2TB of space on my second HD. TM recommends backing up to an HD that is twice the size of the drive being backed up. My op sys drive is a 2TB, so dedicating a 4TB drive for backup storage is a bit over the top, especially as my op sys folders and files only occupy a few dozen GB and are the only folders and files that I need TM to back up. Everything else is backed up separately.

My set up of drives is as follows:

All Desktops and Laptops and networked.
Mac Pro: Internal 2TB + 2TB + 4TB + External 4TB.
Dell Windows Desktop: Internal 1TB + 2TB + External 1TB + 1TB + 2TB
Windows Laptop 1: Internal 1TB
Windows Laptop 2: Internal 500GB
Windows Laptop 3: Internal 500GB

Several External 500GB Drives on shelf not networked and
A huge stack of Optical CD and DVD discs that go back to the early days of Optical drives.

As can be seen, I have no shortage of space for backing up my docs and pictures etc. I just need TM to handle my op sys related folders and files.

Thanks everyone for your very helpful posts.

Peter B.

P.S. I still think that TM could use a makeover. IMHO of course, don't want to upset the apple cart. No pun intended!

Here is a screen shot of the TM exclusion list.

That exclusion list looks OK as long as toy remember to back those up elsewhere regularly.

Also one minor clarification to what you have posted so far:
As you mentioned the general recommendation is that the TM backup drive be 1.5 to 2 times as large as the drive you are trying to back up. In reality TM behaves just as well if the drive is about 2 times the space that is used on the drive. Plus a little give room knowing that additional files will be added later.

In your case having a space of a few dozen GB could be backed up to something smaller than 2 TB. Some people even put their Time Machine backup on a partition of a larger drive though having the drive fail can cause loss of the backup and data on the other partition.

Hi Sly,

I was going to increase the partition size for the TM files on my Y2 2TB drive but changed my mind. I did a get info on the partition and see that TM has only used up a little over 30GB of space so I am leaving well alone, at least for the time being.

All of my personal files on my op sys drive Y1 2TB are either copied or moved to my Mac Pro external 4TB drive so there is no worry about losing them. There are also copies on my Dell drives.

I have software on the Dell and my primary laptop that with a couple of mouse clicks will do incremental (New, Changed etc) backups to and from my Mac Pro drives. The software is not automatic and has to be started manually, but I am on my system everyday, so when I have made a lot of additions or changes, I set it about its business when I am all done at the end of the day. Sometimes it is cooked in a few minutes, and sometimes it can take a few hours to complete.

My only concern is a Mac system failure, so hopefully TM can address that possibility. I can also copy the TM files to another location I suppose to hedge the bets a little bit in my favour.

Peter B.

I had a 1tb WD MyBook hooked up to my 1tb iMac for backup. It had roughly 500gb stuff on it. The backup drive NEVER got anywhere near full.
I imagine it would eventually but the iMac fried before that happened. It will be used to restore on my new computer when I get it.

cradom said:

I had a 1tb WD MyBook hooked up to my 1tb iMac for backup. It had roughly 500gb stuff on it. The backup drive NEVER got anywhere near full.
I imagine it would eventually but the iMac fried before that happened. It will be used to restore on my new computer when I get it.

Click to expand...

Good idea Craig, I have backups of backups of backups. Been doing it since DOS 1.X hit the market. Used to use a DOS app called simply bac.com. It worked great on an IBM PC 286 processor, 256k mem, 30 Meg HD... but it took a lot of floppies to copy everything...

Ah the good old days. I still have about 10,000 floppies in storage...I should burn them all, literally...

Peter B.