Time Machine backups… vanished 😳

[vastunghia]

Dear Mac gurus,

I’m here to report the strangest (and possibly most frustrating) situation I have ever encountered in my long (and often strange and frustrating) Mac experience.

So here we go:

1. On Dec 5, 2022 I wiped an external 4TB HD drive and set it up as my only Time Machine backup disk for my iMac 21.5” 2019. [NB: the TM disk was encrypted but the key was stored in my keychain, so I never had to type it in — of course other users on the same iMac had to, if they wanted to see drive contents]
2. Since then, I never had any problem related to TM, and kept happily accumulating incremental backups.
3. A few days ago, I had to wipe my Macintosh HD (a 2TB SSD) as my local reseller had to replace it under warranty (its performance was not at par with its specs… also check this thread here).
4. I am a pretty risk-averse kind of person, so of course I double- and triple-checked to have TM backups available. Not only did I trigger a back-up just minutes before formatting Macintosh HD (and checked for the latest back-up date and time to reflect what expected before pulling the plug), I also recently browsed through all TM back-ups (I think I had 20-30 of them) via BackupLoupe, just out of curiosity, to understand which files were eating TM disk space most. So yeah, I had all of my incremental backups from Dec 5 till Mar 20, normally browsable via Finder as well as via BackupLoupe.
5. Yesterday I brought back home my iMac with the new SSD installed, fired up Recovery Mode, chose to restore from TM backup… and the only backup available on external TM drive turns out to be the first one (dated Dec 5)!!!

This really hurt me bad. I still have to understand what I lost, but it is going to be painful.

Now my question is: what went wrong?

The only idea I came up with was that for some reason in the past months incremental back-ups (after initial back-up) were stored as local snapshots on my Macintosh HD — which is gone now of course.

But can it be the case? I mean, is it possible that maybe Ventura recognized TM drive as unreachable for some reason (being the disk encrypted should not be a suspected, as I always found it properly mounted on Desktop) and decided to keep local snapshots, waiting for the TM external drive to come back online (even though it was, actually)?

I’m astonished.

Thank you

 

[Fishrrman]

A Fishrrman "there he goes again, like a broken record™" suggestion:
I can't help you with the "vanished" tm backups.

But... in the future... if you want backups that WON'T "vanish" on you...
... then switch to either CarbonCopyCloner or SuperDuper.

Either one will "be there for you" in that "moment of extreme need"...

 

[vastunghia]

Thanks for your comments.

So, 1st question: is this it? I mean, is Apple really so unreliable?

Cause I don’t this is limited to TM, is it? I recall lost files due to bad sync on iCloud (at least back in the days of Mobile Me), and I stopped using iCloud e-mail as apparently some incoming messages are simply deleted by Apple upon reception (that is, not moved to archive, trash or spam: simply vanished).

And if so, 2nd question: in your experience, has it always been like this? Or are we facing a regression in recent times?

Thanks

Ps: I really would love to understand if it is possible that my backup snapshots remained sitting on my Macintosh HD for all these months, without hitting the TM drive. There must be a clear answer to this one!

 

[Brian33]

Now my question is: what went wrong?

The only idea I came up with was that for some reason in the past months incremental back-ups (after initial back-up) were stored as local snapshots on my Macintosh HD — which is gone now of course.

My understanding (and my experience) is that TM deletes local snapshots after 24 hours. Perhaps there is an exception to this though, if the backup drive has not been connected for an extended period of time.

I've never used BackupLoupe. It's not clear to me whether you saw the non-initial backups in BackupLoupe or directly in Finder. If you only observed them in BackupLoupe, maybe that program has a feature that includes local snapshots in its display of backups? And, to further hypothesize, when you connected your backup drive (even if multiple times), perhaps it wasn't connected long enough for TM to kick in and copy the local snapshot backups to the external drive? Maybe this only happens during a "normal" backup, i.e., every hour.

That's all I can come up with at the moment. I often browse this forum and read Time Machine related threads and I haven't seen this behavior reported before. My experience with TM has been very reliable, but I also do backups with CCC just in case.

The only other factor that seems unusual is that the drive was apparently encrypted before you set up TM to use it. But I don't think that was the problem, either. After all, you report that TM (or Finder?) can see the initial backup now -- so it's able to decrypt the volume ok.

 

[vastunghia]

My understanding (and my experience) is that TM deletes local snapshots after 24 hours. Perhaps there is an exception to this though, if the backup drive has not been connected for an extended period of time.

Yup, exactly my hypothesis.

However my TM drive was connected 24-7 to my iMac. So for some reason my Mac must have thought that it was not available, while actually it was? Very twisted plot here.

Also consider that my Mac always reported the correct date as the last backup date. It was never more than a few hours old. To my knowledge, local snapshots should not be accounted for determining last backup date.

So yeah, my hypothesis is very fragile. But what else then?

I've never used BackupLoupe. It's not clear to me whether you saw the non-initial backups in BackupLoupe or directly in Finder.

Both in BackupLoupe and Finder 🤷‍♂️

That's all I can come up with at the moment. I often browse this forum and read Time Machine related threads and I haven't seen this behavior reported before. My experience with TM has been very reliable, but I also do backups with CCC just in case.

Really appreciate a lot your feedback.

I too have been relying on TM for quite a few years now and what just happened to me is mind blowing. Being unable to understand what went wrong is driving me nuts. I’m a rational person so I guess in a couple of months I will start thinking that I dreamt of browsing through my 20+ backups both in Finder and BUL… as that would look like the only reasonable (and reassuring) explanation.

I mean, if you told me this story, I wouldn’t believe it.

But I didn’t dream. They were there, and I recently also passed quite a long time analyzing (with the help of BUL) how a few big files were being backed up over and over quite frequently.

So they were definitely there.

The only other factor that seems unusual is that the drive was apparently encrypted before you set up TM to use it. But I don't think that was the problem, either. After all, you report that TM (or Finder?) can see the initial backup now -- so it's able to decrypt the volume ok.

Correct. But the drive was online 24-7, it was mounted, I could browse it. So yes, I thought about encryption as the culprit too, but still this does make no sense at all.

Last desperate shot: could some malware take possession of the Mac to the point where it was storing backups somewhere else and tricking the OS into thinking that they were where they should be — on the TM drive? Sounds nuts huh… but I really don’t know what to think. Next will come aliens.

Guess will try some data recovery software on the TM disk as soon as I‘m done restoring my system, just to check for missing backups lying somewhere down in the rabbit hole of the disk free space…

 

[gilby101]

Now my question is: what went wrong?

Are you installing the exact same version of macOS (on the new SSD) as you were using on the old one?

Next will come aliens.

But first, I suggest completing a vanilla install of macOS, updating to the latest version, and then use Finder to see what is on the TM disk.

If you only observed them in BackupLoupe, maybe that program has a feature that includes local snapshots in its display of backups?

BackupLoupe does not analyse local snapshots. It analyses snapshots on the TM disk.

 

[vastunghia]

Are you installing the exact same version of macOS (on the new SSD) as you were using on the old one?

Correct. Latest version of Ventura.

But first, I suggest completing a vanilla install of macOS, updating to the latest version, and then use Finder to see what is on the TM disk.

Yes, done. And there is only one backup — the initial one dated Dec 5.

What killed my hopes of recovering more recent backups is that Disk Utility shows only 1.1TB of used space on the TM drive. While I know for sure that it should be at least 1.4 (more probably around 2TB), as my 0.7TB Photo library was moved from one location to another at a certain point, so it was backed up twice.

And once again I do know that because I checked that this was the case both in Finder and in BackupLoupe back in the days… in fact I was planning to drop from TM the first backup copy of my Photo library anytime soon… so glad I didn’t do it yet in the end 😰

BackupLoupe does not analyse local snapshots. It analyses snapshots on the TM disk.

This is the most mysterious issue I have ever encountered in my long Mac experience.

Let’s try and be more rational, sticking to the facts:

1. Last thing I did before turning Mac off was triggering a new backup. And then checked for TM last backup date to reflect current time.
2. Then I accessed Recovery mode and wiped Macintosh HD (with the external encrypted TM drive plugged in… but this should mean nothing, even because it is encrypted and Recovery mode didn’t ask for any key, so it probably didn’t even mount it… no harm could be done at this stage).
3. During the 48 hours in which my iMac was in the shop, the TM drive just sit on my desk.
4. When I brought home my iMac, I found that the guy had already installed Ventura. I wanted to do a clean install myself, so I wiped the new SSD (while I should have simply made a clean re-install of Ventura, damn)
5. This meant that my Mac’s built-in Recovery mode became capable of installing Mojave only, but I thought “hey, should not be a problem, I have a Ventura TM backup, let’s use it”
6. So from Recovery mode I chose to restore from TM, unlocked the encrypted TM drive with my key, and… I was presented with a list of (null) back-ups to restore from. Something was pretty weird, it seemed like back-ups were there but Recovery mode could not interpret them correctly — where it was supposed to show me a list of back-up dates and times, it was showing a list of empty strings.
7. So I prepared a Ventura install USB stick from my wife’s MacBook and fired it up.
8. Picked “restore from TM”, and finally was presented with a correct list of back-ups… apart from the fact that there was only one back-up — the initial one dated Dec 5.
9. So I decided not to trust TM and opted for a clean Ventura install, manually restoring what could be restored from my only surviving back-up.

Step 6 is the most suspected here I guess. Is it possible that for some reason my Mac built-in Recovery mode (based on Mojave) had problems reading Ventura-originated backups and messed with them to the point where all of incremental backups-ups have been removed from disk? Sounds so strange to me…

 

[dcmaccam]

Was the first backup with Ventura as the OS?
I believe Mojave/Ventura requires a base OS to be installed as TM only backs up the Data. So that might be the reason for the problem with step 6.
Furthermore I think that APFS uses soft links which gives better use of space on the backup disk. So if you are backing up a lot of unchanged files it just links to them. (Not sure if this is 100% the way to describe it).
Too late now but I would have installed a bare system. Did a restore of the Dec 5th backup. Then once that was complete go into the restore and see if any other backups appear.
What you can do once you have manually sorted out you files is try going through the motions of doing a restore but don’t actually do it. You can then see what backups you will be presented with.

 

[vastunghia]

Was the first backup with Ventura as the OS?

That's a positive.

I believe Mojave/Ventura requires a base OS to be installed as TM only backs up the Data. So that might be the reason for the problem with step 6.

Well I guess that it should be able to install an OS (Mojave in the case of an empty iMac19,2 as in my case) just before restoring TM data.

Furthermore I think that APFS uses soft links which gives better use of space on the backup disk. So if you are backing up a lot of unchanged files it just links to them. (Not sure if this is 100% the way to describe it).

Mmh I would be surprised if soft links were used for TM backups, always thought they must be hard. However not sure I can see what difference it should make in my case?

Too late now but I would have installed a bare system. Did a restore of the Dec 5th backup. Then once that was complete go into the restore and see if any other backups appear.
What you can do once you have manually sorted out you files is try going through the motions of doing a restore but don’t actually do it. You can then see what backups you will be presented with.

I can do that, but... maybe I was not clear enough, let my try and clarify better:

There is nothing else on the disk. I cannot expect lost data to pop-up at some time in the future.

Wrapping it up, I think that there are two possibilities (both very unlikely):

1. Incremental back-ups were not written on external TM drive for some reason, and remained sitting on Mac HD (till I wiped it and returned it to the shop).
2. Incremental back-ups made it to the external TM drive, but somehow my iMac's Mojave-based Recovery mode wiped all of them (leaving behind only the first back-up) when attempting to parse them.

I think that Disk Drill may help discarding one of the two: if I find any trace of incremental back-ups, 1 cannot be true; if I can't, 2 cannot be. Will give it a shot asap.

 

[dcmaccam]

Ok Good luck. Hope you find some way to recover your items. For future ref. One option is use two TM backup disks so that it would alternately back up on each disk. So if one disk failed you would have the second newest on the other drive.

 

[Boyd01]

This sounds very frustrating, I hope you get it sorted out. Personally, I would never rely on Time Machine for a full disk restore, I use Carbon Copy for that. But, putting that aside, I certainly wouldn't wipe a drive without having three complete backups on separate disks, regardless of the type. One just isn't enough, and I wouldn't even trust two for something that important. Your experience, unfortunately, explains why.

 

[gilby101]

I think you know where it went wrong. Your backups were fine.

In your 9 steps, it is steps 5 and 6 that worry me.

I would not expect a Mojave install to be able to fully read a Ventura TM backup. So Mojave was doing the best it can - and likely messed up the TM disk. Just the process of mounting it might be enough.

Mojave understands APFS (hence able to read TM disk), but does not understand later changes to APFS created for the benefit of TM. "Old macOS does not fully understand future macOS".

As a result Step 9 was the best you can do now.

What you should have done was to update macOS to latest version before attempting to connect the TM backup.

I hope that doesn't sound too patronising - it is easy to be wise after the event.

 

[gilby101]

Furthermore I think that APFS uses soft links which gives better use of space on the backup disk. So if you are backing up a lot of unchanged files it just links to them. (Not sure if this is 100% the way to describe it).

Mmh I would be surprised if soft links were used for TM backups, always thought they must be hard. However not sure I can see what difference it should make in my case?

In the sense of POSIX (Unix) links, TM does not now use links (hard or soft). On an APFS formatted disk, it creates an APFS snapshot for each backup. Older versions of macOS used HFS+ format for TM and used hard links.

 

[EuroChilli]

Ok Good luck. Hope you find some way to recover your items. For future ref. One option is use two TM backup disks so that it would alternately back up on each disk. So if one disk failed you would have the second newest on the other drive.

I actually use 4 disks for TM backups, 1 of which is kept at my father-in-laws house down the road which I rotate with one of the others every now and again. €120 for a 5TB Seagate HDD on Amazon. Slow, but they work, and I'm using APFS on them. Collectively between my wife and I we have around 2.2TB of extremely sentimental/priceless video and photos, most of which is kept on a Samsung 2TB SSD (T7) which is also included in the TM backups to the HDD's, along with what we have on our M1 Airs running Ventura. I have tested and tested, restoring random files from the various drives just to be sure it all works, and it does.

But on the original problem; I too am very curious to know exactly what happened here.

 

[vastunghia]

Ok Good luck. Hope you find some way to recover your items. For future ref. One option is use two TM backup disks so that it would alternately back up on each disk. So if one disk failed you would have the second newest on the other drive.

This sounds very frustrating, I hope you get it sorted out. Personally, I would never rely on Time Machine for a full disk restore, I use Carbon Copy for that. But, putting that aside, I certainly wouldn't wipe a drive without having three complete backups on separate disks, regardless of the type. One just isn't enough, and I wouldn't even trust two for something that important. Your experience, unfortunately, explains why.

I actually use 4 disks for TM backups, 1 of which is kept at my father-in-laws house down the road which I rotate with one of the others every now and again. €120 for a 5TB Seagate HDD on Amazon. Slow, but they work, and I'm using APFS on them. Collectively between my wife and I we have around 2.2TB of extremely sentimental/priceless video and photos, most of which is kept on a Samsung 2TB SSD (T7) which is also included in the TM backups to the HDD's, along with what we have on our M1 Airs running Ventura. I have tested and tested, restoring random files from the various drives just to be sure it all works, and it does.

But on the original problem; I too am very curious to know exactly what happened here.

Thank you all. To be clear, at the moment I completely lost any faith in the possibility of recovering my incremental back-ups -- by the way, so far it seems that I didn't lose much at the end of the day, mostly thanks to iCould. But I need to understand what happened, in order to 1. decide whether I want to trust TM anymore and 2. avoid this happening in the future.

Many thanks for your advice, should I decide to stick with TM at the end of this investigation (say, SuperDuper! being the alternative) I will consider redundancy for sure. As a side note, I thought I was risk averse, but I'm biting your dust!

I think you know where it went wrong. Your backups were fine.

In your 9 steps, it is steps 5 and 6 that worry me.

I would not expect a Mojave install to be able to fully read a Ventura TM backup. So Mojave was doing the best it can - and likely messed up the TM disk. Just the process of mounting it might be enough.

Mojave understands APFS (hence able to read TM disk), but does not understand later changes to APFS created for the benefit of TM. "Old macOS does not fully understand future macOS".

In the sense of POSIX (Unix) links, TM does not now use links (hard or soft). On an APFS formatted disk, it creates an APFS snapshot for each backup. Older versions of macOS used HFS+ format for TM and used hard links.

Aha! I completely missed the evolution of TM from HFS+ to APFS. To be honest, I didn't even realize that my TM drive was APFS... I thought I was still living in a world where TM was compatible with HFS+ partitions only, as it relied on hard links! Thanks for bringing me to 2023

So I see, very interesting. And I think I'm starting to understand... guess best hypothesis here is that

1. TM drive was perfectly fine, containing (if I understand correctly how TM for APFS works, 1. initial back-up + 2. incremental back-ups in the form of APFS snapshots).
2. Mojave-based Recovery mode did not speak the "Time Machine for APFS" language correctly (or maybe even the correct dialect of my TM drive's APFS language), so was not able to interpret snapshots as incremental back-ups.
3. Also, I realized that I forgot to mention in my posts above that, after trying to read TM drive from Mojave-based Recovery mode, I also ran Disk Utility from the same location. I recall running it twice: the first time it gave me a lot of errors which I cannot remember (crying that there were too many of them and that further messages would be suppressed); the second attempt went clean. So I think that this step was the one: somehow, Disk Utility erased APFS snapshots from the TM drive.

As a result Step 9 was the best you can do now.

What you should have done was to update macOS to latest version before attempting to connect the TM backup.

I hope that doesn't sound too patronising - it is easy to be wise after the event.

Not at all, thanks for your super useful hints: I'm looking for a way to avoid repeating this nightmare (and also, as a secondary objective, confirm to myself that my mental health is fine, as I didn't just imagine to browse through incremental back-ups on my TM drive), so any suggestion is strongly appreciated

Now, not that I'm really so interested into recovering my snapshots, but... even though I have no clue on how APFS works and, more specifically, how snapshots are stored, if the above hypothesis is correct it means that data is still somewhere on my disk. I mean, Disk Utility probably did something like "unlinking" snapshots, i.e. removing references to these snapshots. But snapshots need to be still there. Any idea on the possibility of recovering them? Given that APFS seems to be quite a black box, I don't have much faith, but...

PS: found here very interesting resources for understanding how TM for APFS works.

 

[gilby101]

Now, not that I'm really so interested into recovering my snapshots, but... even though I have no clue on how APFS works and, more specifically, how snapshots are stored, if the above hypothesis is correct it means that data is still somewhere on my disk. I mean, Disk Utility probably did something like "unlinking" snapshots, i.e. removing references to these snapshots. But snapshots need to be still there. Any idea on the possibility of recovering them? Given that APFS seems to be quite a black box, I don't have much faith, but...

Your thoughts about unlinking snapshots are, I suspect, very close to the mark. The "consumer" recovery tools are looking for blocks of data that can be linked into files. The difficulty with this (for APFS) is that the blocks of data have more layers between them and the structure of files. Snapshots in particular are interposed between files and their data. For the "ordinary" user (even if a Mac "expert") this makes any recovery very hard.

I am not confident that "professional" recovery companies can do much better. Maybe if you had state secrets...

Whilst this sounds like doom and gloom and a backward step for macOS, I believe that APFS is a step forward in terms of robustness which means that recovery is seldom necessary.

To me, the instructive part of your labours and turmoil is how mixing disks from different version of macOS can lead to disaster (or near disaster).

If you were following in my footsteps , you could continue to have faith in Time Machine. (The alternatives like CCC and SuperDuper would be susceptible to the same or similar issues). But you would do something about fall back off-site backups using a different backup tool. I use Arq Backup and store my backups in both! OneDrive and Backblaze B2. But there are choices - another story.

ps. I don't have any real "in depth" understanding of APFS snapshots. Just enough to get by. Looking for a single source of expertise that I can (just about) follow, I go to https://eclecticlight.co/mac-problem-solving/ where articles going back to Big Sur remain very relevant.

 

[EuroChilli]

I'm going to try to sound like I know what I'm talking about....

I must admit, I was a bit dubious about using APFS on traditional spinners for TM but it seems the latest versions of APFS work just fine on HDD's. Also, what I really like is you don't have to partition the drive if you use the same physical disk for multiple TM backups (I back my wife's and my computer up on the same disks). With HFS+ you could put multiple TM backups in the same volume, but I preferred to partition, in case of logical corruption. The problem with that is you had to decide up front how much each TM backup might need. Now with APFS TM won't let you put them in the same volume, but each separate TM volume automatically takes as much space as it needs. Also, my TM backups using APFS on HDD's don't seem to be filling up the drives nearly as fast as HFS+ did. Instead of months, I'm going to have backups going back several years

And one more thing; With HFS+ TM backups, if you changed the name of a massive folder, TM would make another complete separate backup of such a folder and you would soon run out of backup disk space (Been there, done that. This one time, at band camp, I was still using HFS+ for TM, and I had a folder with multiple Photos libraries in it, about 1.5TB in total. I renamed the folder......) Now, with APFS, it doesn't do that. It's smart enough to know only the folder name has changed but nothing in it. You can go back in time and see the old folder name, but there remains only one instance of it, or something to that effect.

 

[vastunghia]

Your thoughts about unlinking snapshots are, I suspect, very close to the mark. [...] For the "ordinary" user (even if a Mac "expert") this makes any recovery very hard.

I am not confident that "professional" recovery companies can do much better. Maybe if you had state secrets...

Yes, I'm not even giving it a try.

To me, the instructive part of your labours and turmoil is how mixing disks from different version of macOS can lead to disaster (or near disaster).

Yes, that's the main takeaway here -- the lesson learned, as they say.

What brought to the disaster, in a nutshell:

1. I thought of myself as a somewhat advanced Mac user, but
2. I didn't know that Time Machine had evolved from HFS+ to APFS -- in fact
3. I didn't even realized that my TM drive was APFS;
4. given all of the above, I didn't know that old versions of MacOS could have difficulties in accessing TM backups performed on later versions,
5. and of course I didn't know that an old version of Disk Utility could wipe all snapshots from an APFS TM drive (well know you also know it -- don't try this at home!).
6. Furthermore, I didn't even realize that the Recovery mode I was using was based on Mojave instead of Ventura (I realized that later, when I tried to do a clean install of MacOS and was presented with Mojave).

Now yes, if you want to make fun of me, you can say that the only real issue, in this issue list, is # 1 I think it would be fair.

I'm going to try to sound like I know what I'm talking about.... [...]

Also, what I really like is [...]

And one more thing [...]

Whilst this sounds like doom and gloom and a backward step for macOS, I believe that APFS is a step forward in terms of robustness which means that recovery is seldom necessary.

Well, I guess I've learnt that TM for APFS is a beautifully crafted piece of software, working seamlessly and in a very smart way -- much more than his predecessor, TM for HFS+. However, a little bit as the latter had the problem of ending up generating millions of hard links, the former has the problem of being so technologically advanced that -- if you accidentally plug the drive into an older OS version (and like, not 10-years old... we are talking about 2019), well then your TB back-ups could be toasted by friendly fire.

Of course, all of the above because TM does not want to be just a back-up tool, but also a versioning tool. So it has to be intrinsically complex.

I guess that what I will do in the future will be having a 24-7 TM backup drive plugged in (mainly for versioning), just as before; and another dedicated external drive that I will use with SuperDuper! in order to have one plain-vanilla clone copy of the Mac on a drive, without complex architecture like those (super-smart and super-black-box) APFS snapshots that TM is relying on.

ps. I don't have any real "in depth" understanding of APFS snapshots. Just enough to get by. Looking for a single source of expertise that I can (just about) follow, I go to https://eclecticlight.co/mac-problem-solving/ where articles going back to Big Sur remain very relevant.

Yup, thanks, stumbled upon this site earlier today, this helped me a lot, very well written!

Well, I guess that's all folks, thanks a lot for your support, much appreciated!

Hope I won't have to write on this forum for something like this in the future.

 

[MacCheetah3]

I know I am late to the party, but the topic interests me as I’ve pondered, “Is one TM backup enough?"

Step 6 is the most suspected here I guess. Is it possible that for some reason my Mac built-in Recovery mode (based on Mojave) had problems reading Ventura-originated backups and messed with them to the point where all of incremental backups-ups have been removed from disk? Sounds so strange to me…

This was my theory leading up to your guess: Migration Assistant had troubles reading/understanding some aspect of the backup tree and “fixed” or “cleaned” up things as it saw fit.

Coincidentally, over the years, I’ve ‘refreshed’ (i.e., reformatted) my Time Machine drive several times. At least one instance because macOS complained of low space and wouldn’t auto-remove old backups. At least a few times because of unexpected drive failures — I’ve sworn off Seagate thus far, three drives failing <2 years is not acceptable. Ultimately, I think, (re)creating the initial backup from a more current macOS can help with compatibility problems.

P.S. I’ve gone so far as to — gasp? -- buy TechTool Pro to actively monitor the SMART status of my USB drive.