Large hard drives won't mount after restart in Mac Pro 2012

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Large hard drives won't mount after restart in Mac Pro 2012

This post closely follows a previous thread: 6TB drives won't mount after restart in Mac Pro 2012

I have had a very similar problem with a Mac Pro 2012, running either 10.10.5 or 10.13.3 off a SSD. Upon restart or Option-restart, the system will not mount the following disks:

6TB WD Black WD6002FZWZ

8TB HGST He8 HUH728080ALE600

8TB WD Red (white labeled OEM version WD80EMAZ)

Other details:

- On cold boot or option-boot, all of these drives will mount, and all the drives work great.

- Two different systems are affected exactly the same way: Yosemite HFS on SATA 3 sled or High Sierra APFS on PCI card.

- None of the drives are formatted involving a Logical Volume Group (this was a red herring in the last thread).

- One of the effected drives (WD Red) has a 2TB partition with Yosemite on it. Upon option-restart, this partition shows up on the option screen and is selectable. If selected, the system gets part way through startup, then a grey circle with line through it appears. This would seem to imply the problem is not a time-out waiting for the drives to spin up as has been suggested in the previous thread. Rather something is causing the drives to shut down or unmount part way through startup (including the startup partition).

- 2 of the 3 drives are SATA 3.3 compliant and have a remote power-off on pin 3. But in all cases pin 3 is manually taped off (and the problem does not occur on cold restart), so I am sure it is not a PWDIS issue.

Posted on Mar 30, 2018 10:54 AM

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Answer 1

reldauts Author

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Mar 31, 2018 1:13 PM in response to Grant Bennet-Alder

Previously I had been assuming (as you have) that recognition of the disk on the startup screen and appearance of apple and progress bar during startup implies the disk was mounted. But I am pretty sure now that's not the case. With a warm restart, the computer may be using a lot of cached information from the previous cold reboot. If I hold command-v down as I select the system on the affected HDD, I never get an apple or progress bar, just the prohibitory symbol.

Below is the verbose screen spew following option-coldboot vs. option-restart. In both cases command-v was held down upon selection of the system on "BDA," initiating the screen spew. The first image is the normal startup. The second image is the stalled restart. The third image shows the prohibitory screen that appears with the "still waiting for root device"

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Answer 2

Mar 30, 2018 1:10 PM in response to reldauts

- One of the effected drives (WD Red) has a 2TB partition with Yosemite on it. Upon option-restart, this partition shows up on the option screen and is selectable. If selected, the system gets part way through startup, then a grey circle with line through it appears.

Au contraire, it indicates that the MacOS on that partition tried to start up, but some components are damaged. You need to re-Install MacOS on that one.

If it were not ready or could not be booted for some similar reason, you would get the blinking Question Mark.

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Answer 3

reldauts Author

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Mar 30, 2018 1:19 PM in response to Grant Bennet-Alder

If I do a cold option reboot, and select the Yosemite partition on the HDD, it starts up normally. This problem only occurs on restart or option restart, and it happens regardless of which system I select. It's the same 3 HDDs that are all affected. They are all new, they all are fine if rebooted cold.

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Answer 4

reldauts Author

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Mar 30, 2018 2:08 PM in response to Grant Bennet-Alder

Here's a new data point. As a fourth system option, I installed Yosemite on the 6TB WD Black (as single partition), and then tried to select on option-restart. I get the Prohibitory Symbol (grey circle with line through it) about 80% of the way through the restart. But if I shut down and option reboot, it starts up fine.

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Answer 5

Mar 30, 2018 2:55 PM in response to reldauts

The solid Apple is not in the Mac's ROM at startup. The Apple logo can only appear when it is fetched in the first "blob" of software loaded from a 'magic' place on the boot drive. Then a whole lot of stuff is initialized, and the progress Bar moves part way across. Seeing the solid Apple appear says your drive is not completely dead.

The next step requires a lot of files by name, so the File System is initialized, and the Boot Drive is Mounted. If the drive directory is damaged, the drive can not be Mounted, so your Mac begins one pass of Disk Utility Repair. This will take an additional about five minutes. During this process, the progress bar may be extended, and will grow by an additional amount not seen on a routine startup.

If you get the Prohibitory sign at this point, it indicates some of the components of MacOS are damaged or missing.

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Answer 6

reldauts Author

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Mar 30, 2018 9:04 PM in response to Grant Bennet-Alder

If I understand your hypothesis correctly, you are arguing there may be something damaged or missing in the system files. This does not seem consistent with some of the case details:

1) The computer starts up normally off the same HDD if rebooted cold (not restarted).

2) The computer restarts normally from a carbon copy of the same system on a SSD or older HDD.

3) If restarted from a SSD, the 3 HDDs in question do not appear in diskutil list. It's only systems on these three drives that freeze on restart. So I think the failure to mount is correlated from failure to complete restart.

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Answer 7

Mar 31, 2018 6:58 AM in response to Grant Bennet-Alder

It might be interesting to look at the System Log for clues. The Beginning of Startup is marked in the log with the words:"BOOT TIME" in all Caps.

Or just put that log in a scrolling list own the screen by starting in Verbose mode. This has the advantage that you can hear and feel when the drive stops responding, even if the log keeps spewing messages.

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Answer 8

reldauts Author

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Mar 31, 2018 10:12 AM in response to Grant Bennet-Alder

OK, I looked at the system logs during startup. For this test I did not start up on one of the affected drives, but rather a sled-mounted SSD, comparing cold reboot to warm restart. Also in this case I only had one of the 3 affected drives installed ("BDA" = 6TB WD Black). I then looked carefully at the outputs of kernel[0] around the time physical volumes get mounted.

When cold rebooted I find the following log line:

Mar 31 09:27:36 localhost kernel[0]: hfs: mounted BDA on device disk1s2IOBluetoothUSBDFU::probe

When warm restarted, this line is missing and there is no log line with either "BDA" or "disk1s2" in it. So from this it seems the affected disk is never mounting.

I will try one more test, starting up on BDA itself and report shortly.

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Answer 9

reldauts Author

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Mar 31, 2018 10:42 AM in response to reldauts

More info. If I compare cold boot vs restart on the 6TB WD Black ("BDA"), just looking at screen output caused by verbose log, a cold boot results in the following line:

"hfs: mounted BDA on device root_device"

The system then restarts normally. On the other hand if I initiate a warm restart with BDA selected as the startup volume, I do not get any text for a long time, and then get single line outputs every 30-60 secs or so:

"still waiting for root device"

and no startup.

I opened the case while the computer was in this state, and felt the hard drive. It is definitely powered and spinning. If I pull it out of the SATA connector it powers down. If I then plug it back in it spins up, but does not mount.

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Answer 10

reldauts Author

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Mar 31, 2018 10:45 AM in response to reldauts

Also, the appearance of the prohibitory symbol on the screen is synchronous with the appearance of "still waiting for root device" on the bottom of screen. So I think it's pretty clear: The problem stems from the drive never being mounted in the first place.

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Answer 11

Mar 31, 2018 11:05 AM in response to reldauts

That sounds like the drive can not be Mounted at the point where the loaded and initialized File System wants to read its contents as Files.

But it was able to do the "brute force" loading of the first Blob of software that gives you the solid Apple.

That is MUCH more convoluted than I ever imagined.

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Answer 12

reldauts Author

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Mar 31, 2018 1:35 PM in response to reldauts

Anyway, you can see that under the errant startup a number of things are missing, notably:

"Got boot device...

"BSD root: disk1s2...

"hfs: mounted [BDA] on device root_device

and all further notifications citing dev/disk1s2

As I mentioned above the disk is powered and spinning, so it's definitely a failure to mount, not any kind of power failure.

*sigh*

I have no clue why this is happening.

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Answer 13

Mar 31, 2018 2:11 PM in response to reldauts

I think you have it with this from your previous post:

With a warm restart, the computer may be using a lot of cached information from the previous cold reboot.

Since this is a RE-Start, it may simply be Restarting the Kernel code already in RAM, and the correlation between seeing the solid Apple and "it got that off the drive just now" does not hold -- it got the solid Apple off the drive yesterday.

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Answer 14

Apr 2, 2018 4:08 PM in response to reldauts

In my opinion, the newer versions of MacOS are going to the drives sooner than older versions -- and the drives are not ready in that amount of time.

A cold start gives them a little more time, and an older MacOS (probably before serious all-disk encryption and drive containers around 10.8) gave them more time because MacOS used to get all the way to the login screen before secondary drives were even looked at.

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Answer 15

reldauts Author

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Apr 4, 2018 3:15 PM in response to Grant Bennet-Alder

More data. I tried a brand new (2018) 4TB WD Black WD4005FZBX. Same symptoms: mounts on cold boot but not on warm restart. So it's not about drive capacity being >4TB. The only outward stat difference is the cache size (256 MB instead of 64 for the older model).

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Large hard drives won't mount after restart in Mac Pro 2012

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