Six Lessons Learned from Dealing with an iMac's Dead SSD

Article Comments
25

Interesting possibility! In this case, I don’t think that’s happening since it appears as Unknown in the SATA section of System Information.

Thanks! I figured that these techniques weren’t necessarily things people did every day, so it was worth a few more words to explain how to do them as well.

Fingers crossed it doesn’t come to that, since Apple doesn’t seem to be doing too well with repairing Mac Pros.

Apple has a policy of supporting the two previous macOS versions, so that would be Mojave and High Sierra. Once the next version of macOS comes out, however, High Sierra will be kicked off the back of the train. Another thing to consider when pondering an upgrade.

In thinking about your situation, I would recommend buying a new iMac right away. Doing that gives you the opportunity to transition to it gently while the old iMac continues to work as you’ve come to expect. Also, it will be loads faster for the exact sort of things you’re doing. In fact, I’d buy the new iMac, start using it immediately, and only rely on the old iMac for parts of the workflow that can’t be transitioned immediately. Those can then be moved over as you have time.

DiskWarrior has long been a great app, but I have to say, I haven’t used it in decades. Mac drives, particularly SSDs in my experience, don’t seem to suffer directory problems nearly as often as they used to. If Disk Utility can’t fix something, I’d prefer to reformat and restore rather than trust that any third-party could do better than Apple’s own engineers, particularly given that APFS documentation is still sparse, as I understand it. I would never recommend holding up an upgrade for DiskWarrior. Just make sure you have great backups.

Interestingly, the old 2014 iMac I got back from @jcenters had a Fusion Drive, and it looks like he split it. The SSD is largely non-functional (the Finder asks to initialize it, but it always fails in Disk Utility) and while the hard drive seems to work, I strongly suspect that the machine’s flakiness is due to having the dead SSD in there.

1 Like
26

In another thread, @Simon just shed some light on one of my mysteries—why my Mojave installer claimed it was corrupted.

Since my external SSD was empty, I didn’t even think to copy the Mojave installer to the SSD and install from there. Why would the installer care where it was being launched from?

1 Like
27

Just one word of warning from someone who has lived with a dead internal drive (HDD) for years in his iMac 27" late 2012. After the drive failed, it was still mounting, which caused problems at times even when I managed to erase it. I edited fstab to unmount the drive automatically:

  1. identify the drive using (in Terminal) diskutil list (mine was /dev/disk1s2)
  2. find the UUID using diskutil info /dev/disk1s2 | grepUUID (mine was 158A8B51-0C4F-490B-9432-FB1767AAAC07)
  3. edit /etc/fstab using an editor compatible with the Terminal, adding the line:
    UUID=158A8B51-0C4F-490B-9432-FB1767AAAC07 none hfs rw,noauto 0 0 (substitute your own UUID)

This unmounts the drive automatically but you can expect trouble at times, particularly when updating your operating system on your external drive (mine is an SSD connected by USB 3.0). It can take an eternity to complete, and I have at times had to abort the process and retry, so far successfully. I really ought to open the machine up and remove the offending HDD, replacing it with the SSD - I have the tools and the replacement adhesive strips, but have never bitten the bullet.

Yes, maybe it is a bit long in the tooth but it’s still running after seven and a half years, and I don’t think this is the right time to be buying a new iMac with rumours of a new model flying around. Besides, I still use software (Dreamweaver and Audacity to name but two) which won’t run under Catalina.

1 Like
28

I am running Audacity 2.3.2 fine with Catalina (10.15.3).

2 Likes
29

I’m surprised you didn’t just get a 1TB Samsung external SSD and use that as the boot drive. Not really expensive and these drives are fast. I had a base model 21.5 iMac with the world’s slowest HD that my wife used. Doing updates and maintenance on the system was so horribly slow that I finally just got the Samsung SSD and booted off that drive - it made the system much more responsive.

David

30

A post was merged into an existing topic: Your Mac Can No Longer Listen for Aliens, but It Could Help Cure COVID-19

31

That’s exactly what I did, and apart from slow boot and shutdown times, it seems to be working perfectly.

1 Like
32

I wonder if you could just delete all of its partitions, so there’s nothing to mount.

But I suspect that would end up causing the Finder and/or Disk Utility to present its “would you like to format a new drive” dialog every time you log in.

I wonder if there may be some other option to make the system ignore the drive.

33

A post was split to a new topic: Thoughts about buying a new iMac now?

34

The “Damaged Installer” results from an expired certificate. It may not always be an option to download a new installer. One solution is to change the date on your Mac to the date that’s on the installer. Get Info on the version of Install macOS xxx and look at the Modified Date. Set the System Date to that date. In Tools select Terminal and in Terminal firstly enter date and you will get the current time and date looking like this: Sat 2 Nov 2019 12:48:47 AEDT. To change it to 14 June 2019 at 12:24, the date I downloaded my last version of Mojave, you would enter: date 061212232019, then return to the Installer and it will work. I have used this trick to install old systems like El Capitan on old hardware and it is reliable.

1 Like
36

This isn’t all of the problem.

As @adam pointed out above, I downloaded a fresh Mojave installer from Apple just the other day and while it ran from my internal SSD boot volume, it refused to launch from an external HDD and instead gave me the usual damaged installer error. This is not just an expired certificate / date issue. There’s obviously more to it.

37

I’ve been pondering this too, but as far as I can imagine, the only way is a physical disconnection. And if you’re going in, you may as well replace the bad drive.

38

Just a few weeks after I bought my beloved 9600 Mac it was announced that the much anticipated, soon to be released OS X would only run on Intel Macs. Because it ran on RISC chips, for years I was shut out of upgrades and new applications. This became an even bigger bummer when soon after prices on all RISC Macs began to drop dramatically. As good a machine as it was, and it still has a place of honor near my desk, it became almost obsolete shortly after its birth. Although my very ancient MacBook Pro has been slowly but steadily manifesting signs of imminent death and its OS hasn’t been upgradable for years, I’ve been holding out for an A series replacement. My husband is hanging on with his MacBook Pro for the same reasons.

My advice is to stick it out unless you cannot avoid waiting. If you don’t like the A series Macs when they are released, it’s likely you’ll be able to get a better price on a current model.

39

Samsung literature for the T5 says, “Even when using USB 3.0 connections, T5 may not perform well if your system does not support UASP (USB Attached SCSI Protocol). Please make sure that your system supports UASP.”

I’m reasonably confident that my 2015 MacBook does not support UASP (since I can find no mention of UASP or SCSI in the USB portion of the System Report). How much “not perform well” am I likely to see? (Note that I would be buying a T5 disk for a Macintosh to be named at a later date, but using it with the MacBook until that later date.) Thanks.

1 Like
40

Yes, deleting the whole drive might work, and I’ve found a couple of web pages which give instructions on that. The fstab method unmounts the drive at some stage in the boot process but earlier in the process, the drive mounts. I think that’s where the problem occurs when updating the operating system (and sometimes when doing a security update). I think that the request to format the drive would probably come later in the boot process but I can’t be sure of that. I’ll need to think it through - it might be safer to open up the iMac and take out the HDD.

41

There’s never a right time to buy a new computer, other than when you need one. The fault with mine is not down to Apple (other than a poor choice of supplier) - it’s the Seagate 3.0GB drive which is known to be prone to failure. If it’s any help, I will definitely buy another iMac after this one (it replaced the previous generation of iMac 24 inch) but the design (at least on the exterior) hasn’t changed in over ten years and it must be nearly time for a redesign.

42

I also installed an SSD kit a year ago in my 2014 27" iMac 5K. Prior to that I used a Samsung T5 as my boot drive for about six months and things felt faster, but nothing compared to what I’m realizing now with the internal SSD.

There are times where I crave a faster iMac, but Python, shell scripts, and Affinity Designer are just fine with the old gal.

I’m lucky to also use a 13" MacBook Pro from work and use Jump Desktop to connect to it from the iMac since I run Windows via Parallels Desktop sometimes.

I honestly feel my iMac has much more value than what I would get if I sold it. The display is pretty cool. I also use Parallels Tools with Switch Resolution in the menu bar and sometimes take advantage of the full 5K when my eyesight is doing well.

By the way, I’m using an older 2010 iMac 27" in Target Display Mode as my second display and that’s a nice setup. :slight_smile:

43

I have never seen this mentioned there either, despite using some of the latest USB3 docks that I know offer support for UASP.

I have been told that in order to really check you have to look under Software > Extensions and check which kernel extension is actually loaded, IOUSBAttachedSCSI or IOUSBMasStorageDriver. If the former is loaded you are using it, if only the latter is loaded you are defaulting back to the old USB MSC. I have only seen the latter on this 2013 MBP so I’m assuming its USB3 is simply too old to support it.

44

Adam, I also thank you for the detailed write up. Articles like this (and all the comments) are one of the primary reasons I subscribe to Tidbits. And I agree with Doug Hogg – this kept me riveted in my seat to the end.
Some of my interest was generated by trying to update my 2013 MacBook Air to High Sierra. (yeah - I don’t keep up with all the new stuff :slight_smile: I was forced into an upgrade after installing a new application which could not run under Sierra. And the Mac App Store wasn’t helpful as it was forcing me to jump straight to Catalina. I did not want that because of some 32-bit apps that would be left behind.

It was quite an effort to find a link to the correct Apple installer. Just wish I’d seen Roland Mansson’s post with all the handy-dandy links right there. Gotta keep a copy of that one! Will likely move on to Mojave now that he has provided the article with its link to the installer.

1 Like
45

A quick web search finds this Apple discussion thread from 2014. The procedure described is:

  • Run the ioreg command to get the entire USB device tree, capturing its output to a file
  • Look for lines with devices of class IOUSBDevice and IOUSBAttachedSCSI. These are your UASP devices
  • Non-UASP storage devices will be of the IOUSBMassStorageClass

(The original version of this post mentioned an iousb command. That was a typo. Sorry.)