Weird "diskutil list" situation...

[andysh]

Hi guys!
On my MBP I just upgraded to El Capitan with a fresh install, using an external USB key.
On my drive there was only one partition with Snow Leopard. And I erased everything with Disk Utility included in the El Capitan installer.
Now everything works, but typing "diskutil list", here's what I get. And it seems to be weird to me.
There's an "internal, physical" and an "internal, virtual" drive. But I only have 1 SSD and I don't understand why there's this dual thing.
My question is: what is that physical, virtual drive? How can I erase that?
Here's what I see:

 

[JohnDS]

I think this article will explain what is going on:

http://eclecticlight.co/2015/12/28/...restorage-changes-hard-drives-and-their-care/

or

https://www.reddit.com/r/osx/comments/2wzlxc/a_corestorage_primer_aka_why_you_cant_manipulate/

or

http://arstechnica.com/apple/2014/10/os-x-10-10/2/

 

[Weaselboy]

Totally normal and nothing to worry about. Just leave it be.

If you install Yosemite or El Capitan on a Mac portable with a CPU that supports AES-NI, and there is no Bootcamp (Windows) partition present, the installer converts the drive into a "core storage" logical volume that you are seeing there.

There are quit a few articles around about this such as the ones linked by JohnDS, but nobody is really quite sure why Apple did this. But it does not seem to harm anything.

 

[andysh]

Guys,
I'm still not convinced about that internal virtual drive on my MBP...

Why? When I try to press the alt key on boot there's no recovery option, just the osx drive (but in my diskutil it is there, part of the disk0).

Instead, on my Mac Pro with El Capitan there's no trace of that virtual drive and the recovery option works.

 

[DeltaMac]

You can boot to your recovery system by restarting while holding Command-R

I think it does not appear in the Option/Alt-boot screen because of the Core Storage configuration.
You may have done an OS X update to get El Cap on your other Mac, and the core storage volume would probably not have set up when doing an upgrade - but your clean instal did that on your MBPro. Not really affecting anything for you, except that Option-boot doesn't make the recovery partition appear. Boot with Command-R to get the recovery system to boot.

 

[andysh]

You can boot to your recovery system by restarting while holding Command-R

Thank you @DeltaMac I knew that but at this point why it doesn't show up with the option key? Don't you think that it is weird?
[doublepost=1459302748][/doublepost]@DeltaMac in both macs I did a fresh install from an USB key. In both macs before there was Snow Leopard (so no recovery partition at all) and everytime I erased everything and installed from scratch

 

[DeltaMac]

Then, maybe the difference is the drive arrangement on your Macpro. Perhaps the core storage does not extend to your PCIe/SSD setup on that.
At any rate, the difference should not cause you any difficulty - other than my lame attempt at a technical answer

 

[andysh]

Ok, so it seems that on this Mac it won't never show up in the startup manager but only holding down Command-R.
Apple apple apple...
From: https://support.apple.com/en-us/HT204417

 

[DeltaMac]

Cool!