Internal drive sometimes not mounting

[msintros]

One of my internal drives (not a boot drive) sometimes will just not mount and is not visible in the Disk Utility.

Sometimes when waking the computer from sleep, it will give me a message in the top right saying something about it (I think that it is not unmounted properly or something, but I can't remember exactly). Usually it will come back after a restart, sometimes not.

I don't know if the drive is failing but it runs fine when it is mounted and doesn't ever disappear while the computer is running, only when it has been asleep.

Any tips?

 

[h9826790]

Which HDD? which Mac? which OS? Do you mean a warm restart can bring back the drive? Or a cold boot is required?

 

[msintros]

Sorry, should have included that. 500 GB internal on a Mac Pro 5,1 running Mavericks.

That's a good question about warm restart vs. cold reboot, I am not entirely sure. It is gone right now, so I might try just a warm restart to see if it comes back.

EDIT: Ok, yes, a warm reboot just brought it back.

 

[h9826790]

Sorry, should have included that. 500 GB internal on a Mac Pro 5,1 running Mavericks.

That's a good question about warm restart vs. cold reboot, I am not entirely sure. It is gone right now, so I might try just a warm restart to see if it comes back.

EDIT: Ok, yes, a warm reboot just brought it back.

The stock WD Black 500GB HDD?

 

[msintros]

System profiler says it's a Hitachi HDS7250SASUN500G

 

[orph]

it may be about to die, id back up the data on it.
or it may just not be plunged in correctly, try removing then reinserting the drive by hand.

 

[h9826790]

it may be about to die, id back up the data on it.
or it may just not be plunged in correctly, try removing then reinserting the drive by hand.

Agree, and better try to install into another slot