MP 1,1-5,1 Hard drive disappears sporadically

[s.m.t.]

I have been having an issue with a 6TB Seagate drive that will occasionally disappear as if it was removed from the system. Doing a complete shutdown, cold restart is the only way it will show up again. If I just do a warm reboot it will not appear in finder or disk utility. First aid in disk utility reports healthy, I even have DriveDX running constantly in the background and it does so any faults either.

That wouldn't be a too big of a problem if it wasn't for the fact that when the drive is seen again, Time Machine acts like it has never seen it and performs a full backup of it. The drive have just over 5.5TB used and the very next backup after the drive returns shows that much pending. My TM target disk is only 10TB so this kills my long term protection. It is not an issue with the full never completing as I have gone over a month before the drive disappears. Though the past two times have happened just over a week of each other.

I am running a 4,1 MP flashed to 5,1 so I initial thought it might be a variation of the large drive warm/cold reboot issue.

 

[h9826790]

I have been having an issue with a 6TB Seagate drive that will occasionally disappear as if it was removed from the system. Doing a complete shutdown, cold restart is the only way it will show up again. If I just do a warm reboot it will not appear in finder or disk utility. First aid in disk utility reports healthy, I even have DriveDX running constantly in the background and it does so any faults either.

That wouldn't be a too big of a problem if it wasn't for the fact that when the drive is seen again, Time Machine acts like it has never seen it and performs a full backup of it. The drive have just over 5.5TB used and the very next backup after the drive returns shows that much pending. My TM target disk is only 10TB so this kills my long term protection. It is not an issue with the full never completing as I have gone over a month before the drive disappears. Though the past two times have happened just over a week of each other.

I am running a 4,1 MP flashed to 5,1 so I initial thought it might be a variation of the large drive warm/cold reboot issue.

This is a known issue. I think which is covered in this thread. No solution so far.

MacPro 5.1 & high capacity hard drives

I've run out of internal storage on my MacPro 5.1. And although I have a 24 bay NAS in the background, I need more high speed storage. I would think my cheapest option would be to upgrade to larger disks, as I currently run 4x2TB in Raid0. Does anyone have experience running larger disk, such...

forums.macrumors.com

 

[s.m.t.]

I am aware of that thread and have posted there several times. To be clear this issue is not happening *during* a cold or warm reboot... It occurs after the system has been running for an extended period of time.

Also everything I have read suggest TM should just pick back up like normal and not do a full backup as if it was the first time seeing the drive.

 

[h9826790]

I am aware of that thread and have posted there several times. To be clear this issue is not happening *during* a cold or warm reboot... It occurs after the system has been running for an extended period of time.

Also everything I have read suggest TM should just pick back up like normal and not do a full backup as if it was the first time seeing the drive.

Did you tried the pin 3 tape fix yet?

 

[s.m.t.]

No, I have not. The drive shows up fine on a cold or a warm reboot, so didn't think to try that. Seems odd to be functional for days to weeks without reboots, then have it randomly disappear... Wondering if there is a log somewhere that might give some insight as to what is happening...

The bigger annoyance is figuring out why TM thinks it is a brand new drive every time it reappears...