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cynics

macrumors G4
Original poster
Jan 8, 2012
11,959
2,156
Can someone explain this for me.

Screen Shot 2016-12-19 at 5.36.02 PM.png

From what I'm gathering it wanted to delete my TM and restart it correct?

Its been over 24 hours and the TM control panel still says "Preparing Backup". If I cancel that, in the upper right under TM it says "Preparing to Complete First Back up".

Should I continue to wait? There is no network activity from that Mac or into the NAS.

Screen Shot 2016-12-19 at 6.33.05 PM.png

I'm starting to lose my mind. I been able to move somethings to external drives but I'm out of space so I'm assuming I don't have a backup currently. There are a lot of things I can't afford (literally) to lose this is why I'm using a back up in RAID.

In my time machine folder there is a file which I'm assuming is my previous backup labeled as "My Name iMac.purgeable" what is this? Should I move it out of that folder? Delete it? Somehow restore it?

Is there something I should be doing? My backup is going to be nearly 2 terabytes so maybe this wait is normal?

Any help is greatly appreciated!
 

casperes1996

macrumors 604
Jan 26, 2014
7,593
5,764
Horsens, Denmark
From what I'm gathering it wanted to delete my TM and restart it correct?

The message appears when a backup is corrupted. Time Machine indeed wants to delete your backup, and replace it with a brand new one. The reason your backup is labelled as purgeable, is because Time Machine thinks it's ready to be deleted. If you have important information in the backup, there are ways that you may recover the backup to a working state again.

Here's a guide
http://thefunkstop.com/fix-corrupted-time-machine-backups/

If it's OK for the backup to be deleted, click start new backup and wait it out. With more than 2TB, the process could easily take days depending on the storage, how you connect to it etc.
 
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cynics

macrumors G4
Original poster
Jan 8, 2012
11,959
2,156
The message appears when a backup is corrupted. Time Machine indeed wants to delete your backup, and replace it with a brand new one. The reason your backup is labelled as purgeable, is because Time Machine thinks it's ready to be deleted. If you have important information in the backup, there are ways that you may recover the backup to a working state again.

Here's a guide
http://thefunkstop.com/fix-corrupted-time-machine-backups/

If it's OK for the backup to be deleted, click start new backup and wait it out. With more than 2TB, the process could easily take days depending on the storage, how you connect to it etc.

Thanks I woke up this morning and noticed the size of that purgeable file was drastically smaller and the drives were clicking away (doing something).

I'm hoping to see it starting to back up by the time I'm home from work today.

I'm guessing your correct something was corrupted however prior to all this I clicked back up later and sorted through my TM to make sure there was nothing I had deleted that would be lost forever. Everything "seemed" ok, I was able to sort through over a year back and pull out some random files without a problem. I don't normally use my TM like that but I think paranoia set in.

Fingers crossed I have a TM back up when I get home. I just ordered some more NAS drives for me to manually back up things in the event this happens again.

Thanks again for your help.
 

cynics

macrumors G4
Original poster
Jan 8, 2012
11,959
2,156
Sure. Any time. For long term storage, aside from Time Capsule, I manually put files on the drive too, next to my TM file. TM is a great "Oh ****, i've lost something that I now realise I need again" solution, but it often corrupts.

I see that now. Fortunately it doesn't appear that it will effect me much but now that I have some larger NAS drives coming I'm going to keep a manual back up too just for a couple certain things.

It appears I was just being impatient (hopefully) so I guess I'm glad Apples software saw some sort of corruption happening. This is better then it not working when I actually need it. If I could change anything about is a more detail description of what it's doing like "currently removing previous back up" then that measured in megabytes or something with a completion bar not just "preparing back up".
 

casperes1996

macrumors 604
Jan 26, 2014
7,593
5,764
Horsens, Denmark
It appears I was just being impatient (hopefully) so I guess I'm glad Apples software saw some sort of corruption happening. This is better then it not working when I actually need it. If I could change anything about is a more detail description of what it's doing like "currently removing previous back up" then that measured in megabytes or something with a completion bar not just "preparing back up".

This would definitely be nice. I've had the same thoughts you have when my TM first went corrupted. At this point it happens once every 6 months or so, so get used to this process...

^Note - The above is with 2 Macs using the TM, and it's one corruption every six months, not one per machine
 
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cynics

macrumors G4
Original poster
Jan 8, 2012
11,959
2,156
Screen Shot 2016-12-20 at 6.12.07 PM.png

It probably took a total of nearly 3 days but it got it done.

I really didn't like that it took that long although I guess I understand why being it was dealing with such a large backup across a network. If something would have happened during that time (my luck) I would have been SOL.

Greater care and preparation will be taken in the future for very important things.
 

saudor

macrumors 68000
Jul 18, 2011
1,511
2,114
View attachment 679457

It probably took a total of nearly 3 days but it got it done.

I really didn't like that it took that long although I guess I understand why being it was dealing with such a large backup across a network. If something would have happened during that time (my luck) I would have been SOL.

Greater care and preparation will be taken in the future for very important things.
depending on the nature of the content, it may be a good idea to keep an offsite backup and rotate it out. Time machine should allow you to round-robin multiple backup disks

If a backup is bad and your main disk is bad, you can fall back to a 2nd backup disk
 
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cynics

macrumors G4
Original poster
Jan 8, 2012
11,959
2,156
Well, I'm glad it finally worked for you :). If it should happen again, you can always connect the backup drive to the computer with a cable while the first backup takes place, to speed up the process.

Hmm...

So its happened 3 times (today being the 3rd) since my initial post. Last time I tried manually deleting everything to do with my back up and starting from scratch. Open my computer today and I have the same error again and it wants to redo the back up.

What is going on? What should I be looking for and what should I try to correct this? I would prefer to continue using Time Machine now that I have all my files manually backed up.

Thanks.

BTW the only thing that I can think that has changed was the update to Sierra ~2 months prior to the first failure. However its seems to happen more frequent then that so I'm not completely convinced of Sierra being the problem i.e. it lasted for 2 months once why can't it again?
[doublepost=1486503715][/doublepost]I think what I'm going to try to do is turn off automatic back up. Then just back up occasionally with a click when I sit down at my computer just to see what happens.
 

KALLT

macrumors 603
Sep 23, 2008
5,380
3,415
It is a known problem with Time Machine on NAS. It needs to have a constant connection to the disk image while backing up and it seems to be fragile. If Time Machine detects irregularities in the disk image, it will distrust the entire backup.

Which protocol are you using to access the image? AFP? SMB?
 

casperes1996

macrumors 604
Jan 26, 2014
7,593
5,764
Horsens, Denmark
What is going on? What should I be looking for and what should I try to correct this? I would prefer to continue using Time Machine now that I have all my files manually backed up.

Look through this:
http://jd-powered.net/notes/fixing-your-time-machine-backup

As someone else said, TM can be a bit picky with connections and whatnot, and will flag fully working backups as broken sometimes. The above can fix it. Well, as in you might still get problems going forward, but it will save the current bunch of backups. However, I got about 5 of these failures in one month a while back, and then it just stopped and I haven't had a single since (quite a while ago now).
 

cynics

macrumors G4
Original poster
Jan 8, 2012
11,959
2,156
It is a known problem with Time Machine on NAS. It needs to have a constant connection to the disk image while backing up and it seems to be fragile. If Time Machine detects irregularities in the disk image, it will distrust the entire backup.

Which protocol are you using to access the image? AFP? SMB?

AFP

Thanks for the info. Its strange I had around a 1 year 6 months of backups before this started happening.
[doublepost=1486514095][/doublepost]
Look through this:
http://jd-powered.net/notes/fixing-your-time-machine-backup

As someone else said, TM can be a bit picky with connections and whatnot, and will flag fully working backups as broken sometimes. The above can fix it. Well, as in you might still get problems going forward, but it will save the current bunch of backups. However, I got about 5 of these failures in one month a while back, and then it just stopped and I haven't had a single since (quite a while ago now).

Perfect. I bookmarked the site and will try that when it happens again. Thanks again for your help.
 

KALLT

macrumors 603
Sep 23, 2008
5,380
3,415
Apple added support for SMB sharing to Time Machine in Sierra. The SMB developers are currently making the changes. One commenter mentioned that you could get better results when you are sharing an actual HFS+ file system instead of a sparse image.
 

stooovie

macrumors 6502a
Nov 21, 2010
836
314
OP: don't use Time Machine on NAS. It's not reliable, and there's nothing you can about it. There are tons of reports of the same issue for almost ten years now and I had it too on three different NASes. Just don't do it. Also, it's much slower than any directly connected disk.
 
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