Wiping a MBP - many partitions on the SSD

The Mercurian

macrumors 68000
Original poster
Mar 17, 2012
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So I'm wiping a MBP getting it ready to sell. ran the terminal command diskutil list and there are 20 partitions there! This machine is on High Sierra with APFs system. There are disks 0, 1, & 2 which all realte to the system and thats fine. but there are 17 more small partitions (512Kb to 6.3Mb in size and I have no clue what they are about. Are these important or can I wipe and merge them ?
 

The Mercurian

macrumors 68000
Original poster
Mar 17, 2012
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Yes I know all that already. I';m doing more than that, I'm doing secure erase through the terminal. I want to know why there are so many partitions and can I delete them.
 

chabig

macrumors 603
Sep 6, 2002
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Yes I know all that already. I'm doing more than that, I'm doing secure erase through the terminal. I want to know why there are so many partitions and can I delete them.
Why? Don't know.
Can you delete them? Yes. You can repartition to a single partition. When you reinstall the OS it will automatically create a recovery partition.
 
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Weaselboy

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Staff member
Jan 23, 2005
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Yes I know all that already. I';m doing more than that, I'm doing secure erase through the terminal. I want to know why there are so many partitions and can I delete them.
I'm guessing you are seeing these from Recovery? Those are small virtual drives the installer uses and totally normal. They will disappear when the install is done and you reboot.
 
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RobbieTT

macrumors 6502
Apr 3, 2010
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Sounds a bit odd to me - are you sure you have that many partitions on your drive rather than containers or perhaps AFPS volumes?
[doublepost=1543163319][/doublepost]Mine, for reference:

Screenshot 2018-11-25 at 16.27.09.png
 

Weaselboy

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Staff member
Jan 23, 2005
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Oh ok, didn't know the Recovery boot used partitions rather than volumes. Every day a school day!
Yeah.... if you are in recovery and run diskutil list in Terminal you can see them all like here. I'm thinking that is what OP is seeing.

Code:
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *128.0 GB disk0
1: EFI 209.7 MB disk0s1
2: Apple_HFS HD 127.2 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: Apple_partition_scheme *1.4 GB disk1
1: Apple_partition_map 30.7 KB disk1s1
2: Apple_Driver_ATAPI 2.0 KB disk1s2
3: Apple_HFS Mac OS X Base System 1.4 GB disk1s3
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk2
/dev/disk3
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk3
/dev/disk4
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk4
/dev/disk5
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk5
/dev/disk6
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk6
/dev/disk7
#: TYPE NAME SIZE IDENTIFIER
0: untitled *6.3 MB disk7
/dev/disk8
#: TYPE NAME SIZE IDENTIFIER
0: untitled *2.1 MB disk8
/dev/disk9
#: TYPE NAME SIZE IDENTIFIER
0: untitled *1.0 MB disk9
/dev/disk10
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk10
/dev/disk11
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk11
/dev/disk12
#: TYPE NAME SIZE IDENTIFIER
0: untitled *1.0 MB disk12
 
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vk2fro

macrumors member
Apr 29, 2015
91
36
Sydney, Australia
Yep - and like the OP when you first see this behaviour in the terminal you go WTF?! However /dev/disk0 is nearly ALWAYS your internal SSD/HDD.
 

The Mercurian

macrumors 68000
Original poster
Mar 17, 2012
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Yeah.... if you are in recovery and run diskutil list in Terminal you can see them all like here. I'm thinking that is what OP is seeing.

Code:
/dev/disk0
#: TYPE NAME SIZE IDENTIFIER
0: GUID_partition_scheme *128.0 GB disk0
1: EFI 209.7 MB disk0s1
2: Apple_HFS HD 127.2 GB disk0s2
3: Apple_Boot Recovery HD 650.0 MB disk0s3
/dev/disk1
#: TYPE NAME SIZE IDENTIFIER
0: Apple_partition_scheme *1.4 GB disk1
1: Apple_partition_map 30.7 KB disk1s1
2: Apple_Driver_ATAPI 2.0 KB disk1s2
3: Apple_HFS Mac OS X Base System 1.4 GB disk1s3
/dev/disk2
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk2
/dev/disk3
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk3
/dev/disk4
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk4
/dev/disk5
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk5
/dev/disk6
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk6
/dev/disk7
#: TYPE NAME SIZE IDENTIFIER
0: untitled *6.3 MB disk7
/dev/disk8
#: TYPE NAME SIZE IDENTIFIER
0: untitled *2.1 MB disk8
/dev/disk9
#: TYPE NAME SIZE IDENTIFIER
0: untitled *1.0 MB disk9
/dev/disk10
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk10
/dev/disk11
#: TYPE NAME SIZE IDENTIFIER
0: untitled *524.3 KB disk11
/dev/disk12
#: TYPE NAME SIZE IDENTIFIER
0: untitled *1.0 MB disk12

Yes this is what I'm seeing. They also only show up when in recovery mode - they don't show up when booted normally into MacOs and using terminal. but if you reboot under Command-R then run terminal from the Utilities menu they show up. They do seem to persist.
 

vk2fro

macrumors member
Apr 29, 2015
91
36
Sydney, Australia
Yep thats just the installer/recovery creating the tmp, etc, var, swap and other "volumes". They are located in ram. Since during regular boot MacOS has already created them post install, there is no need for them to exist on a normal boot. When recovery or install is invoked, the directories are stored in a ramdisk so the installer can use them.
 
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