To erase the old efs partition I used windows. That's not the case. What interesting is, when I boot holding alt key and select SSD the problem doesn't occur.
the problem began before i do that. and as you said, when I boot holding alt key and select SSD the problem doesn't occur.Maybe the EFI partition was messed up because you used a non-mac.
what could be the problem?
Sorry, what was that?Did you follow up on my suggestion?
… I'm kinda out of ideas here short of either the SSD or enclosure being bad.
… again (the prohibited sign). …
No, there is not.To the right of those two, is there ever a third startup option?
No it is not.Is FileVault 2 enabled for one or both of the disks?
I wonder what this errors and etc. Means.here is the screen capture of the verbose mode (cmd+V) during boot:
Just a guess, but could it be possible that the USB device is port powered and starts off in low power mode and the system has to kick it into high power mode to start the unit up? If that's the case and the unit has a provision to be externally powered then supplying external power to the unit may stop that from happening.
This is a guess, …
I don't have relevant experience with SSD enclosures but next time you find the prohibitory sign, try disconnecting then reconnecting the drive without switching off the Mac. That might sound scary – and if it's a verbose boot, the aftermath of reconnection might appear alarmingly garbled – but I'd like to know whether the Mac can be 'forced' to progress past that sign.
With Recovery OS running, use the menu bar to launch Terminal. Please enter the following command:
diskutil list
Then copy the output from the Terminal window, quit Terminal and (still in Recovery OS) use Safari to log in to MacRumors Forums. Paste to this topic.
-bash-3.2# diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Machintosh HD 300.0 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Apple_HFS HD2 699.2 GB disk0s4
/dev/disk1 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *120.0 GB disk1
1: EFI EFI 209.7 MB disk1s1
2: Apple_HFS SSD 119.2 GB disk1s2
3: Apple_Boot Recovery HD 650.0 MB disk1s3
/dev/disk2 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme +2.1 GB disk2
1: Apple_HFS OS X Base System 2.0 GB disk2s1
/dev/disk3 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +5.2 MB disk3
/dev/disk4 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk4
/dev/disk5 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk5
/dev/disk6 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk6
/dev/disk7 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk7
/dev/disk8 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk8
/dev/disk9 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +6.3 MB disk9
/dev/disk10 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +2.1 MB disk10
/dev/disk11 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +1.0 MB disk11
/dev/disk12 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk12
/dev/disk13 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk13
/dev/disk14 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +1.0 MB disk14
/dev/disk15 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +6.3 MB disk15
-bash-3.2#
-bash-3.2# diskutil list
/dev/disk0 (internal, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *1.0 TB disk0
1: EFI EFI 209.7 MB disk0s1
2: Apple_HFS Machintosh HD 300.0 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
4: Apple_HFS HD2 699.2 GB disk0s4
/dev/disk1 (external, physical):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *120.0 GB disk1
1: EFI EFI 209.7 MB disk1s1
2: Apple_HFS SSD 119.2 GB disk1s2
3: Apple_Boot Recovery HD 650.0 MB disk1s3
/dev/disk2 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme +2.1 GB disk2
1: Apple_HFS OS X Base System 2.0 GB disk2s1
/dev/disk3 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +5.2 MB disk3
/dev/disk4 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk4
/dev/disk5 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk5
/dev/disk6 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk6
/dev/disk7 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk7
/dev/disk8 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk8
/dev/disk9 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +6.3 MB disk9
/dev/disk10 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +2.1 MB disk10
/dev/disk11 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +1.0 MB disk11
/dev/disk12 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk12
/dev/disk13 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +524.3 KB disk13
/dev/disk14 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +1.0 MB disk14
/dev/disk15 (disk image):
#: TYPE NAME SIZE IDENTIFIER
0: untitled +6.3 MB disk15
-bash-3.2#
Only USB powered. But I mentioned before that this problem has began with early versions of 10.10What kind of external enclosure do you have?
Is it self-powered (with a separate cable for power), or is it bus-powered (only a USB cable connected)?
Bus powered can be flaky with some of the "generic" brands, particularly when using as a boot drive.
Only USB powered. But I mentioned before that this problem has began with early versions of 10.10
iMac:~ darkweather$ sudo chown root:admin /
iMac:~ darkweather$ sudo kextcache -system-prelinked-kernel
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
iMac:~ darkweather$ sudo kextcache -system-caches
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
JMicronATA.kext has no Info.plist file.
Bad kernel extensions
/System/Library/Extensions/AppleOSXUSBNCM.kext
any idea what is this and could be relevant to this issue?