el capitan fails to reboot after successful install

Could you copy-paste the following line into the Terminal app's command line and copy-paste the output to a reply:

diskutil list

I assume you need this to be booted under el capitan beta 2 - this will take a little while while I reinstall beta 2 ..... I'll be back soon

Yes, that'll be more informative. However, I am about to go to bed (2:15am where I am), so it'll be a few hours before I get back to you...

Here ya go...

(thanks for your attention to this)

The volume "Oscar" is the one I'm booted from

$ diskutil list

/dev/disk0 (internal, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *240.1 GB disk0

1: EFI EFI 209.7 MB disk0s1

2: Apple_HFS Johnny 239.2 GB disk0s2

3: Apple_Boot Recovery HD 650.0 MB disk0s3

/dev/disk1 (external, physical):

#: TYPE NAME SIZE IDENTIFIER

0: GUID_partition_scheme *1.0 TB disk1

1: EFI EFI 209.7 MB disk1s1

2: Apple_HFS ElCapitan_b2 222.2 GB disk1s2

3: Apple_Boot Recovery HD 650.0 MB disk1s3

4: Apple_HFS Oscar 699.7 GB disk1s4

5: Apple_Boot Recovery HD 650.0 MB disk1s5

the el_capitan_b2 volume was an earlier attempt (it has server 5 and xcode 7 already installed)

Okay, so now the output from:

diskutil info disk1s2

and it behaves the same way

So Oscar is 10.11 DP2 as well? Then also:

diskutil info disk1s4

Now I really am off to bed...

Thanks - catch you tomorrow..

Here's the data:

Yes - Oscar and the el_cap volumes are created from the same beta 2 image

$ diskutil info disk1s4

Device Identifier: disk1s4

Device Node: /dev/disk1s4

Part of Whole: disk1

Device / Media Name: Oscar

Volume Name: Oscar

Mounted: Yes

Mount Point: /

File System Personality: Journaled HFS+

Type (Bundle): hfs

Name (User Visible): Mac OS Extended (Journaled)

Journal: Journal size 65536 KB at offset 0x16a0000

Owners: Enabled

Partition Type: Apple_HFS

OS Can Be Installed: Yes

Recovery Disk: disk1s5

Media Type: Generic

Protocol: USB

SMART Status: Not Supported

Volume UUID: 79911849-302E-380F-80C6-4C2075918AB5

Disk / Partition UUID: FBBE73C7-575C-4DCA-A517-06B05DD8D733

Total Size: 699.7 GB (699708866560 Bytes) (exactly 1366618880 512-Byte-Units)

Volume Free Space: 682.2 GB (682160930816 Bytes) (exactly 1332345568 512-Byte-Units)

Device Block Size: 512 Bytes

Allocation Block Size: 4096 Bytes

Read-Only Media: No

Read-Only Volume: No

Ejectable: Yes

Whole: No

Internal: No

When you say "created from the same beta 2 image", what do yo mean exactly? I would use those terms to mean that I had created an image of a working installation of 10.11 DP2 and copied/cloned it to another drive/partition. Is this what you mean too?

Or is the Oscar partition is the result of installing DP1 from the Installer application you downloaded to a stable OS like 10.10.3 or .4, followed by booting into the fresh OS X 10.11 DP1, and then updating via the App Store to DP2?

Or has it come to be through a process slightly different to the above?

Either way, there is nothing amiss in the partition info you posted - it appears you were booted into the Oscar 10.11DP2 OS when you ran the info command.

The problem you're having might result from a bad shutdown or some bad blocks on your drive with the El Capitan partitions. There are 3 different approaches to resolve or further diagnose this:

• After selecting Oscar from the Apple Bootloader, hold cmd+v to see verbose output of the attempted boot process and find out what goes wrong.
• Boot into Single-User-Mode: Hold down cmd+s immediately after powering on. Wait until the command-line prompt appears (after all the text is done scrolling past). Then type fsck -fy and press Return. Eventually, after five different checks that take varying amounts of time, you should get to one of two messages: "The volume [your Mac's name] appears to be OK" or "FILE SYSTEM WAS MODIFIED." If you encounter the first message, type reboot and press Return. If you see the latter message, though, you'll want to run fsck -fy all over again. You can retype the command and hit Return, or press the Up arrow once and then press Return.
• Booting into 10.11's Recovery Mode and opting for First Aid/Repair Disk in the Utility menu/Disk Utility for the relevant drive+partition. This could be tricky because you have 3 of them and it's hard to tell which one you would boot into just by holding cmd+r at bootup. Selecting the right one from the Bootloader also may not be an option because of it's CoreStorage mode. You'll have to type the following into Terminal, after which you should be able to see 10.11 RecoveryHD in the Bootloader:
  • diskutil cs list
  • diskutil coreStorage revert lvUUID [where lvUUID is the last lvUUID reported by the previous Terminal command.]

To answer some of your questions.

Neither install began with an earlier 10.x. I downloaded the beta copy from Apple developer web site and then installed it directly to fresh (empty) drive partitions. I used the same downloaded image to create both ElCapitan_b2 and Oscar.

Every time I reinstall (I boot from my 10.10.4 and run the installer again against ElCapitan_b2 or Oscar) I'm able to boot just fine.

After a successful install (and doing nothing else) I have tried to simply "Restart" - the results are however, recovery mode and safe mode are not achieveable. I've tried both on different occations. In both situations I get the ( \ ) type response (unbootable partition) after the Apply logo had appeard for several seconds. Then my system continues to look for a bootable partition, finds my 10.10.4 named Johnny, and continues. As soon as 10.10.4 comes up I imediately look in System Prefs to Startup Disk and it shows everything is available (Johnny, ElCapitan_b2, Oscar). Yet if I select one of the 10.11 partitions, and restart, it fails again. If in the process I try cmd-s or cmd-r, I still get the same result - no safe mode, no recovery mode.

I have not tried verbose mode - I'll try that on the next reboot.

If I run Disk Utility (while booted under 10.11 Oscar) and run First Aid against the non-booted 10.11 (ElCapitan_b2), I get...

Repairing file system.

Checking Journaled HFS Plus volume.

Checking extents overflow file.

Checking catalog file.

Checking multi-linked files.

Checking catalog heirarchy.

Checking extended attributes file.

Checking volume bitmap.

Checking volume information.

The volume ElCapitan_b2 appears to be OK.

File system check exit code is 0.

Updaing boot support partitions for the volume as required.

Operation successful...

*** I'm wondering now if those last two lines will make a difference on my next ry (Updating boot support partitions.....)

If I run DU on Oscar (while also booted from it), I get...

Verifying file system.

Using live mode.

Performing live verification.

Checking Journaled HFS Plus volume.

Checking extents overflow file.

Checking catalog file.

Checking multi-linked files.

Checking catalog heirarchy.

Checking extended attributes file.

Checking volume bitmap.

Checking volume information.

The volume ElCapitan_b2 appears to be OK.

File system check exit code is 0.

Operation successful...

Obviously without any updates since its being used.

Got a few things to try - will get back to you.

Thanks again for your time.

You proabably know this, but Safe Mode and Single User Mode are very different. I'm not surprised that Safe Mode won't work, but SUM will - you have to press cmd+s immediately after powering on, not after selecting an OS from the bootloader (but that is when you do it for Verbose Mode - see my post above)

While you're booted into Oscar that first time after installation, we wouldn't expect to find an error in the filesystem. The key will be to run these same tests after it will no longer boot. If you make the 10.11 RecoveryHD visible, it will also allow you to reinstall (preserving your user data), also potentially fixing the issue.

Sorry - I mis-spoke. I did the cmd-s (SUM) without success.

How does one make RecoveryHD "visible"?

The Disk Utility scan I did above on ElCapitan_b2 was done while it was in a state of unrebootable.

I'll try the cmd-s by doing this following in order:

1) select 10.11 in system prefs startup disk

2) shutdown

3) power on and immediately do cmd-s

For SUM, it won't matter what the start-up disk is set to.

I described how to make the RecoveryHD visible in the 3rd bullet point in my long post above.

Good that we can rule out "First Aid" as a solution.

Just to be sure, you do use the Bootloader right? - i.e. holding alt at startup to select the partition you're going to boot into.

Tried the bootloader thing - saw the recovery partitions and tried one - still got the ( \ ) symbol. Tried bootloader again and bootloader never came up - just went past and tried to boot and failed - then booted my internal 10.10. Perhaps I didn't get the key down properly. Haven't tried the other two yet. WIll try them soon.

However, - this seems to be more enlightening. I did verbose mode and got the following on both of my 10.11 partitions....

efiboot loaded from device: Acpi(PNP0A03,0)/Pci(1A|1)/Usb(1, 0)/Usb(2, 0)/HD(Part4,SigFBBE73C7-575C-4DCA-A517-06B05DD8D733)

efiboot file path: \System\Library\CoreServices\boot.efi

Read error 0x7

ERROR!!! Load prelinked kernel with status 0x8000000000000007

Error loading kernel cache (0x7)

Again, I had successfully installed and could run fine - until a reboot - thats when I get the above

Also tried

$ diskutil cs list

No CoreStorage logical volume groups found

Did this under 10.10.4 and also under 10.11 when I had it booted (after a reinstall) - got the same answer.

Still can't get to a recovery partition.

At some point, I'll try to re-download the beta from the developer web site and see if that makes any difference..