Backing up my iMac data using Time Machine connected to an External Hard Disk by Firewire 800 worked fine when my Mac OS was Sierra 10.12.3.
On 9 April I updated to Sierra 10.12.4. Time Machine stopped its automatic backups. It froze at “Preparing for backup…” And when I entered Time Machine from the icon on the top menu bar, the back arrow doesn’t work and it doesn’t allow access to previous backups from the list at the right hand side.
I tried re-installing Mac OS from Recovery, but it didn’t solve the problem.
When I tried a manual backup it showed a blue line “Preparing backup… “ This stays like this for more than an hour. When I pressed Skip Backup it produced an .inProgress file of abou153.MB in the Backups.backupdb folder.
I researched and found that security software, particularly Sophos, prevented Time Machine working after OS updated to 10.12.4. I removed Sophos & re-started iMac. It didn’t solve the problem.
Disk First Aid says there is nothing wrong with Ext HD
As for as permissions go, I have full access to Read and Write on the Backup Ext HD
By contrast, Info on Time Machine.app does not show that I have any permissions. When I unlocked the window and attempted to add Administrators to Name, or to change Privilege, I received an error message
“The operation can’t be completed because you don’t have the necessary permission”.
So I, as the Administrator of my iMac, cannot change permissions to enable me to Read & Write for Time Machine.
I then tried:
(a) Shut down iMac. Disconnect all cables. Wait 30sec. Retart with Alt, Apple, P & R keys depressed ➔ 2 bongs, to re-set everything
(b) Re-start with Shift key down to disable extensions, run diagnostics check, and clear out corrupted files, then normal re-start.
Now Time Machine doesn’t stall at “Preparing backup…” but it backs up incredibly slowly. I managed to get a successful backup, but only by leaving my iMac on overnight. Backup started at 18:41 on 13 May and was completed at 18:13 on 14 May.
On 15 May I re-started my Mac and put Time Machine on Automatic backup, thinking this wouldn’t take long because Time Machine is incremental and there was only a day’s new data, not a month’s new data. However, it started backing up at 12:55 and said “About 22 hours remaining”. At 20:00 “Finishing backup”
On 16 May 09:25 still “Finishing backup”
However, today the Backups.backupdb folder shows that
(a) the 15 May backup that started at 12:24 was modified (completed?) at 18:41 on 15 May.
(b) a 16 May backup created automatically at 10:48 was modified at 15:01
(c) a 17 May backup, 2017-05-17-143240, created automatically at 09:55 was modified at 14:32
but above that, replacing a previous .inProgress Package, is 2017-05-17-095455.inProgress Package.
Moreover, I can Enter Time Machine through the icon on the menu bar and both the back arrows and the dates on the RHS work and I’m able to restore files.
Indebted for any help in making Time Machine function properly, spelled out in simple terms (I'm just an ordinary user with no technical knowledge).
On 9 April I updated to Sierra 10.12.4. Time Machine stopped its automatic backups. It froze at “Preparing for backup…” And when I entered Time Machine from the icon on the top menu bar, the back arrow doesn’t work and it doesn’t allow access to previous backups from the list at the right hand side.
I tried re-installing Mac OS from Recovery, but it didn’t solve the problem.
When I tried a manual backup it showed a blue line “Preparing backup… “ This stays like this for more than an hour. When I pressed Skip Backup it produced an .inProgress file of abou153.MB in the Backups.backupdb folder.
I researched and found that security software, particularly Sophos, prevented Time Machine working after OS updated to 10.12.4. I removed Sophos & re-started iMac. It didn’t solve the problem.
Disk First Aid says there is nothing wrong with Ext HD
As for as permissions go, I have full access to Read and Write on the Backup Ext HD
By contrast, Info on Time Machine.app does not show that I have any permissions. When I unlocked the window and attempted to add Administrators to Name, or to change Privilege, I received an error message
“The operation can’t be completed because you don’t have the necessary permission”.
So I, as the Administrator of my iMac, cannot change permissions to enable me to Read & Write for Time Machine.
I then tried:
(a) Shut down iMac. Disconnect all cables. Wait 30sec. Retart with Alt, Apple, P & R keys depressed ➔ 2 bongs, to re-set everything
(b) Re-start with Shift key down to disable extensions, run diagnostics check, and clear out corrupted files, then normal re-start.
Now Time Machine doesn’t stall at “Preparing backup…” but it backs up incredibly slowly. I managed to get a successful backup, but only by leaving my iMac on overnight. Backup started at 18:41 on 13 May and was completed at 18:13 on 14 May.
On 15 May I re-started my Mac and put Time Machine on Automatic backup, thinking this wouldn’t take long because Time Machine is incremental and there was only a day’s new data, not a month’s new data. However, it started backing up at 12:55 and said “About 22 hours remaining”. At 20:00 “Finishing backup”
On 16 May 09:25 still “Finishing backup”
However, today the Backups.backupdb folder shows that
(a) the 15 May backup that started at 12:24 was modified (completed?) at 18:41 on 15 May.
(b) a 16 May backup created automatically at 10:48 was modified at 15:01
(c) a 17 May backup, 2017-05-17-143240, created automatically at 09:55 was modified at 14:32
but above that, replacing a previous .inProgress Package, is 2017-05-17-095455.inProgress Package.
Moreover, I can Enter Time Machine through the icon on the menu bar and both the back arrows and the dates on the RHS work and I’m able to restore files.
Indebted for any help in making Time Machine function properly, spelled out in simple terms (I'm just an ordinary user with no technical knowledge).