Free space, Mojave on an external APFS SSD

[TomM1]

I started booting my iMac from an external Samsung T5 SSD as it is a big speed improvement over the internal platter drive.
I have noticed the free space diminishing daily on the Ex SSD.
I do create some large files and download photos occasionally but I also delete files as often as possible.
When I first cloned to the drive the free space was about 717 GB. Now it is at 636GB.
Could the rapid decline be a result of the drive being external?

Thanks.

 

[jbarley]

Take a look at this thread, about Time Machine shapshots.
It refers to High Sierra APFS but also applies to Mojave.

https://www.macworld.com/article/3260635/how-to-delete-time-machine-snapshots-on-your-mac.html

 

[TomM1]

Take a look at this thread, about Time Machine shapshots.
It refers to High Sierra APFS but also applies to Mojave.

https://www.macworld.com/article/3260635/how-to-delete-time-machine-snapshots-on-your-mac.html

Thanks. I performed the Terminal search and there was only one Time Machine snapshot which I deleted.
That free space gained is already gone again.

 

[TomM1]

Perhaps it is something related to this "Trim" thing that I have been reading about here.

 

[treekram]

Perhaps it is something related to this "Trim" thing that I have been reading about here.

The amount of free space doesn't change on a TRIM'd disk vs. a non-TRIM'd disk. You also can't get TRIM on the T5 on the Mac.

As to what is causing your issue, if you installed any software that came with the T5, maybe that could be the cause, or perhaps some other 3rd-party software you have installed. If you have a repeatable procedure where you don't have any running apps and then you delete some files and without you doing any action, the free space drops by a large amount (multiple GB), then you can try safe mode and repeat the procedure and see if the same thing happens.
https://support.apple.com/en-us/HT201262

 

[TomM1]

I erased the drive before cloning onto it so I don't think it is the Samsung software.
The only activity that has changed is, I stopped using Photoshop and started using Affinity photo quite heavily.
But I have never heard of AP having any hidden files that would cause the loss of gigs of free space.

 

[Fishrrman]

OP:
Download DiskWave from here:
https://diskwave.barthe.ph
It's small in size and it's free.

Open DiskWave and go to the preferences.
Put a checkmark in "show invisible files".
Close preferences.

The DiskWave window shows you all your drives in plain English (no ridiculous graphical formats).
Click on any drive.
Now, you'll see what's ON the drive, listed in order of "largest to smallest".
You can easily locate what's eating up your space.

What is it?

 

[TomM1]

I confess that I do not understand these numbers.
In the top left we see, Used 390 GB but on the right, it doesn't add up to that.
The last couple of days I have seen available space drop from 623 to 608 GB.
About This Mac>Storage>System shows 221GB. That's up from about 201GB recently.

 

[Fishrrman]

OP:
Important question:
Do you use Time Machine?

 

[TomM1]

OP:
Important question:
Do you use Time Machine?

Yes, on an external drive that I only turn on for manual backups.
You might say:
"Do you use Time Machine?
If so, it's probably the "local backups" eating up your disk space.
My advice (and yes, I sound like a broken record):
STOP USING Time Machine.
Instead, use either CarbonCopyCloner or SuperDuper.
No more wasted drive space on your Mac, and you'll have backups that won't continually "grow" ins size, and which will be instantly finder-mountable (and BOOTABLE) in a "moment of extreme need"."

I could stop using Time Machine, if that is the issue, as I have two other CCC backups.
Some internet sources suggest that TM local backups are only a laptop problem, I have an iMac

Attached is a Terminal search result.

 

[Fishrrman]

I suggest that:
1. You stop using TM
2. Search for and remove all local backups and local snapshots, or whatever the heck they're called.
3. DO start using CCC for your backups.

(but that's what I ALWAYS say!)

 

[TomM1]

I suggest that:
1. You stop using TM
2. Search for and remove all local backups and local snapshots, or whatever the heck they're called.
3. DO start using CCC for your backups.

(but that's what I ALWAYS say!)

I already do number 3.
Using the command tmutil deletelocalsnapshots deleted the one snapshot be did not return the freespace.
I will put put a moratorium on TM and see if the rapid loss of free space stops.

 

[treekram]

Yes, on an external drive that I only turn on for manual backups.
You might say:
"Do you use Time Machine?
If so, it's probably the "local backups" eating up your disk space.
My advice (and yes, I sound like a broken record):
STOP USING Time Machine.
Instead, use either CarbonCopyCloner or SuperDuper.
No more wasted drive space on your Mac, and you'll have backups that won't continually "grow" ins size, and which will be instantly finder-mountable (and BOOTABLE) in a "moment of extreme need"."

I could stop using Time Machine, if that is the issue, as I have two other CCC backups.
Some internet sources suggest that TM local backups are only a laptop problem, I have an iMac

Attached is a Terminal search result.

View attachment 830823

If it's not obvious, you also have CCC snapshots in addition to the one TimeMachine one. If you're not aware of how it works, there's a fairly lengthy article here:
https://bombich.com/kb/ccc5/leveraging-snapshots-on-apfs-volumes

 

[TomM1]

If it's not obvious, you also have CCC snapshots in addition to the one TimeMachine one. If you're not aware of how it works, there's a fairly lengthy article here:
https://bombich.com/kb/ccc5/leveraging-snapshots-on-apfs-volumes

Well well. I just got 170GB back by deleting the CCC snapshots. I saw the CCC snapshots by I thought I had deleted them via Terminal. Not So.
I also didn't realize that snapshots were apart from the CCC safety net.
Thanks for pointing to that.

 

[naerct]

That's great you got your space back. I found a product that I use on my MBP and recommend it for all Macs, especially those with Terminalphobia. The product is called Disk Sensei (nee Trim) and allows TRIM to work on non-Apple SSDs. It also allows you to turn off several controls which Mac turns on by default. The invasive TM writing to the boot happens on iMacs as well. I found out about this problem from a client who only has a 2015 iMac. It also shows files you might want to delete in order. I can use terminal, but with Disk Sensei, it's all in one place. I'm even thinking of putting it on to my bigMac. I think it's still $20/computer, but they may still have a $10 version which ONLY does TRIM-splurge and get the full version as the features are very helpful.

 

[TomM1]

That's great you got your space back. I found a product that I use on my MBP and recommend it for all Macs, especially those with Terminalphobia. The product is called Disk Sensei (nee Trim) and allows TRIM to work on non-Apple SSDs. It also allows you to turn off several controls which Mac turns on by default. The invasive TM writing to the boot happens on iMacs as well. I found out about this problem from a client who only has a 2015 iMac. It also shows files you might want to delete in order. I can use terminal, but with Disk Sensei, it's all in one place. I'm even thinking of putting it on to my bigMac. I think it's still $20/computer, but they may still have a $10 version which ONLY does TRIM-splurge and get the full version as the features are very helpful.

Trim Enabler seems interesting. I would need to get verification that it is effective and safe. BTW CCC shows Time Machine snapshots that are then easily deleted.

 

[naerct]

I was a little curious about how well it worked at first, but I got the basic version and then moved up to Disk Sensei. My client has a similar 2015 iMac i7 with the 4GB VRAM as she is mostly doing photography with Adobe PS and LR where the extra resources really help, especially OpenCL with the VRAM. I have been using Disk Sensei for 4 or 5 years without problems. You can check it works for the TRIM in the System Report under the SATA folder. As far as the other features, you'll need to check them out yourself or with Google, but they have always jived with other apps like Disk Genius and Disk Utility when I've checked them. I'm glad the TM stuff shows up on CCC, but it's not an important feature for me. I am quite happy with SuperDuper for cloning, and I also use it for backing up imagery using "copy newer". This is my client who had the TM filling up her boot drive. She got her iMac with a Fusion Drive, but I separated the 120GB SSD and the 3TB HDD, so it didn't take long for TM to fill the small boot SSD. She used Disk Sensei to keep TM in check with one click. I would never introduce her to THE TERMINAL, too risky and she's 90n minutes away...

 

[Honza1]

Well well. I just got 170GB back by deleting the CCC snapshots. I saw the CCC snapshots by I thought I had deleted them via Terminal. Not So.
I also didn't realize that snapshots were apart from the CCC safety net.
Thanks for pointing to that.

I am living under impression, that snapshots (created by any tool, CC or TM) are part of purgeable space. That should mean, that if user needs more space, they are automatically purged and space is provided. Kind of like what regular memory is now - system keeps filling up memory (or disk) if the space is not needed, purging old content when needed. Basically, "why not use it if we have plenty of it".

Hence, all of these confused & alarmed posts and solutions may do more bad than good. System should take care of the user and we may just be too "proactive" here.

Did anyone actually run into troubles and had to deal with this really manually? That is, did anyone run out of space due to snapshots and crashed the system? I never ever had a problem and deleting manually snapshots would be waste of time.

On the other hand, my disk space is typically around 50% free and purgeable space varies up to ~30-50Gb. I rarely generate more large files in short time... My snapshots seem to disappear automatically after ~24 hours or after I connect time machine disk. I suspect that is how this is suppose to work.

 

[naerct]

I am living under impression, that snapshots (created by any tool, CC or TM) are part of purgeable space. That should mean, that if user needs more space, they are automatically purged and space is provided. Kind of like what regular memory is now - system keeps filling up memory (or disk) if the space is not needed, purging old content when needed. Basically, "why not use it if we have plenty of it".

Hence, all of these confused & alarmed posts and solutions may do more bad than good. System should take care of the user and we may just be too "proactive" here.

Did anyone actually run into troubles and had to deal with this really manually? That is, did anyone run out of space due to snapshots and crashed the system? I never ever had a problem and deleting manually snapshots would be waste of time.

On the other hand, my disk space is typically around 50% free and purgeable space varies up to ~30-50Gb. I rarely generate more large files in short time... My snapshots seem to disappear automatically after ~24 hours or after I connect time machine disk. I suspect that is how this is suppose to work.

When TM took over and there was no room for an OS swap file, the OS wouldn't boot. I had to help my client boot her clone and reclone the internal boot over the phone, as she needed the internal SSD speed to do her work. I don't really know how CCC works after not having seen it in almost a decade. Recently, I have also stopped using TM as my second backup, as I described earlier. It slows things down, takes forever, and is a real space hog. With Super Duper "copy newer", I get real files and it only takes a couple minutes each time, not hours. I think TM has value, but not for my photo workflow.
I also found it a bit implausible that a guy with so much Apple bling lying around could keep his boot drive only half full. Just kidding. On my new NVMe 500GB boot, the system is never more than 100GB, and I have tons of worthless gear that I still store. Do you need any old SCSI cables, adapters, or live terminators? ;-)

 

[TomM1]

I am living under impression, that snapshots (created by any tool, CC or TM) are part of purgeable space. That should mean, that if user needs more space, they are automatically purged and space is provided. Kind of like what regular memory is now - system keeps filling up memory (or disk) if the space is not needed, purging old content when needed. Basically, "why not use it if we have plenty of it".

Hence, all of these confused & alarmed posts and solutions may do more bad than good. System should take care of the user and we may just be too "proactive" here.

Did anyone actually run into troubles and had to deal with this really manually? That is, did anyone run out of space due to snapshots and crashed the system? I never ever had a problem and deleting manually snapshots would be waste of time.

On the other hand, my disk space is typically around 50% free and purgeable space varies up to ~30-50Gb. I rarely generate more large files in short time... My snapshots seem to disappear automatically after ~24 hours or after I connect time machine disk. I suspect that is how this is suppose to work.

Bottom line for me is that I just don't like the software filling up my drive.
It is easy to turn off in CCC.
Somewhere I have read that there are some performance advantages to free space.
[doublepost=1556724205][/doublepost]

I was a little curious about how well it worked at first, but I got the basic version and then moved up to Disk Sensei. My client has a similar 2015 iMac i7 with the 4GB VRAM as she is mostly doing photography with Adobe PS and LR where the extra resources really help, especially OpenCL with the VRAM. I have been using Disk Sensei for 4 or 5 years without problems. You can check it works for the TRIM in the System Report under the SATA folder. As far as the other features, you'll need to check them out yourself or with Google, but they have always jived with other apps like Disk Genius and Disk Utility when I've checked them. I'm glad the TM stuff shows up on CCC, but it's not an important feature for me. I am quite happy with SuperDuper for cloning, and I also use it for backing up imagery using "copy newer". This is my client who had the TM filling up her boot drive. She got her iMac with a Fusion Drive, but I separated the 120GB SSD and the 3TB HDD, so it didn't take long for TM to fill the small boot SSD. She used Disk Sensei to keep TM in check with one click. I would never introduce her to THE TERMINAL, too risky and she's 90n minutes away...

Trim may be a moot point in my situation as it has been suggested in these forums that trim cannot be activated over a USB3 external SSD.

 

[Honza1]

When TM took over and there was no room for an OS swap file, the OS wouldn't boot. I had to help my client boot her clone and reclone the internal boot over the phone, as she needed the internal SSD speed to do her work. I don't really know how CCC works after not having seen it in almost a decade. Recently, I have also stopped using TM as my second backup, as I described earlier. It slows things down, takes forever, and is a real space hog. With Super Duper "copy newer", I get real files and it only takes a couple minutes each time, not hours. I think TM has value, but not for my photo workflow.
I also found it a bit implausible that a guy with so much Apple bling lying around could keep his boot drive only half full. Just kidding. On my new NVMe 500GB boot, the system is never more than 100GB, and I have tons of worthless gear that I still store. Do you need any old SCSI cables, adapters, or live terminators? ;-)

There is a difference between hard drive space and shelf space, you know? I look like collector by now. I just wish I still had some of the really old Apple devices from when I was young - seem to be quite valuable now. But I was too poor then to buy Apple... And thank you, I have few SCCI cables and even older technology still around.

But seriously, this is first time someone stated that they had computer actually run out of space and crash - at least what I heard. If this "run-out-of-space" would be common problem, we would be hearing about unexplained crashes all the time. Most people do not monitor their available disk space. They just use the thing.

 

[naerct]

There is a difference between hard drive space and shelf space, you know? I look like collector by now. I just wish I still had some of the really old Apple devices from when I was young - seem to be quite valuable now. But I was too poor then to buy Apple... And thank you, I have few SCCI cables and even older technology still around.

But seriously, this is first time someone stated that they had computer actually run out of space and crash - at least what I heard. If this "run-out-of-space" would be common problem, we would be hearing about unexplained crashes all the time. Most people do not monitor their available disk space. They just use the thing.

I had never heard of it before either. The problem was twofold. She wanted a big internal dive. The options then were Fusion or big overpriced SSD. At that point I had been using 120GB boot drives, so separated the 120 SSD and the 3TB HDD. Then you combine that with image files that take a lot of space and forget to turn on the the external backup Thunderbay. It was a simple Terminal move, but I found Disk Sensei ($20) that included this switch and several more to save space on your drive, as well as being able to turn on TRIM for non Apple SSDs. Most people don't get to that point as they only have one big drive and don't use so many large files in a session. I could never afford Macs when I was working on my own, I built fast Winboxes from scratch. I still have one in my attic with my Commadore 64. I also had the first Pentium chip with the math errors that I had to replace. Need any ATA ribbon cables? I owned the first ATA CD drive as they had all been SCSI previously. My first CD burner was a 2X, while the blanks cost up to $10 each. A long time ago...