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8mc34

macrumors newbie
Original poster
Aug 7, 2015
2
1
I can't format my new internal SSD to GUID Partition Scheme with Mac OS Extended(Journaled) but Master Boot works fine. When i try, it sticks at 'waiting for disks to reappear'. I have tried first erasing the drive itself which results in a similar error where it sticks at about half way through the progress bar and the time remaining just continues to increase. I have booted from a USB running Yosemite, Internet Recovery, USB installer drive and none have made a difference when it comes to formatting. The drive is currently Master Boot Record and is functioning (verified). My next step is to get a usb to sata connector and try to format the drive externally using a different mac. I have a feeling this won't fix the problem but I am desperate. I have access to a PC and a MAC if there is a solution using a PC to format it first for use internally as the main drive in my MBP Mid 2012. Any help is appreciated.


MBP Mid 2012



SSD is Samsung SSD 850 EVO


MacBook Pro (13-inch Mid 2012), Currently booting off USB flash
 
in DISK UTILITY select your drive on the left hand menu, then select PARTITION, in PARTITION LAYOUT, choose the amount of partitions you want (i.e. if you want just 1 partition select 1), at the bottom click on OPTIONS, and this will give you your choice of GUID etc
 
You should be able to go to the erase tab in Disk Util and select Mac OS Extended (Journaled) then apply that and it will make it GUID by default. If that is causing the error message you described, then you either have a bad drive or a bad drive cable. The bad cable is fairly common with these.
 
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You should be able to go to the erase tab in Disk Util and select Mac OS Extended (Journaled) then apply that and it will make it GUID by default. If that is causing the error message you described, then you either have a bad drive or a bad drive cable. The bad cable is fairly common with these.

I don't think Yosemite will give GUID by default. It uses corestorage or something.
 
I don't think Yosemite will give GUID by default. It uses corestorage or something.
No... that is a different issue. The underlying format is still GUID, then the volume gets converted to core storage during the Yosemite install on newer portables.
 
Thanks everyone. By process of elimination the problem appears to be the cable as someone mentioned. I was able to format and install Yosemite using an external usb to sata adapter. When I attach the drive internally it won't recognize the drive unless in disk utility which just sees it as am I formatted master boot record. I'm going to get a new cable and that should be the end of it. I find it weird that the cable would cause this issue but it does appear to be a common problem
 
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