Moving Time Machine folder "quickly" to top-level directory

[Christopher Kim]

More info below, but the TLDR is I have my TM backups on an external hard drive, but backups.backupdb folder is currently within a subfolder of one of the volumes, not in the main directory. My understanding is that for TM to use this volume now (and continue with the existing TM backups), it needs to be at the top-level (so I can just click the volume under the TM Select Disk).

Is there a way I can move the backups.backupdb folder from the sub-folder up 1 level to the top-level of the volume "quickly" (eg. without the drive actually "moving it"?) My TM backups stretch back 5+ years and are ~1.5TB, and are something like 100,000+ files, so I imagine if it actually moved it, it would take hours (even if on the same drive). Vs if it does a "quick move" (eg. just changes the table / pointer), would expect it's near-instantaneous.

I tried dragging it in Finder to top-level, but a dialog box started saying "Preparing to copy XXX items" and started counting up the files... So I just stopped it (I can let it continue if people think I should try and after it calcs the number of files, it should be a near-instant transfer). I didn't want to try to "Move it" (eg. hold Command and then drag it to the top-level folder in the volume in Finder) in case it will do it the long way (and I'm super worried about canceling a permanent "MOVE" of my backups.backupdb folder).

Some additional info:
- I recently moved my TM backups from an old external drive to a new external drive (both are external USB3.0 enclosures with large spinner HDs)
- I copied the backups.backupdb folder to the new external drive (took ~15hrs), but into a sub-folder of the new external drive because I was moving a bunch of other backup files there as well and created a bunch of interim sub-folders (not realizing the backups.backupdb folder has to be at the top-level of the volume)
- The new external drive is to be a dedicated TM drive (I've since moved all the interim sub-folders off of it), so now the drive just has 1 folder (let's call it "Chris TM Backup", and in that folder is the backups.backupdb folder)

Any help much appreciated.

 

[Brian33]

Interesting. Backups.backupdb appears to be a regular directory. My understanding of hfs+ is that when one moves a file or directory to another place on the same volume, it just changes the file system tables and does not actually copy or move the data. So it should be nearly instantaneous.

I tried dragging it in Finder to top-level, but a dialog box started saying "Preparing to copy XXX items" and started counting up the files... So I just stopped it

I'm guessing that the attempt of Finder to do a copy (instead of a quick move) may be the result of the ownership and permission settings of the volume, its root directory, and/or the Backups.backupdb folder itself. For example, maybe if your user has read access but not write access to the Backups.backupdb folder, Finder would do a copy operation? I don't know, but presumably you could set up test folders with permissions matching your Backups.backupdb to find out.

I'm not even sure what the settings should be for a TM backup, but things to consider include:

The volume's setting for "Ignore Ownership On This Volume" (do a "Get Info" in Finder). Is it checked or unchecked or is that checkbox missing? (On my TM volume -- and only that volume -- that checkbox is missing!)

The ownership and permissions on the root directory of the volume (use 'ls -l' in Terminal to examine). Mine are owned by root and have permissions "drwxrwxr-x"

The ownership and r/w permissions of the Backups.backupdb folder (use 'ls -lhFOe'). Mine looks like this:
drwxr-xr-x+ 6 root wheel - 204B Dec 19 12:27 Backups.backupdb/ 0: group:everyone deny add_file,delete,add_subdirectory,delete_child,writeattr,writeextattr,chown
(The bottom line shows ACL permissions. I don't know if they are relevant or not.) So for me, only user 'root' (or an admin using 'sudo' in Terminal) could remove the Backups.backupdb folder, so I wouldn't be able to move it using Finder.

Again, I'm not sure that yours needs to match mine -- just giving some ideas of what to look for. It is probably possible to do what you want but may take some Terminal commands (mv, chmod, chown) and experimenting...

Brian

 

[Taz Mangus]

Enable root user, login to root user, then try moving the Time Machine backup folder to the root of the drive. It should just move the folder and not copy it. It should be a quick operation from root user.

How to enable the root user or change the root password on Mac - Apple Support

Mac administrators can use the root user account to perform tasks that require access to more areas of the system.

support.apple.com

 

[Christopher Kim]

@Brian33 @Taz Mangus thanks to you both. I enabled the root user, and was able to move the backups.backupdb folder up a level to the root directory of the volume easily and instantaneously (by just holding cmd and dragging the folder to the main volume in Finder).

Worked great, and I remember to disable root user after finishing. Just tried to do another TM backup post the drive move and all went well. Thanks and cheers!