EFI automounts on startup After upgrading to the newest El Capitan from 10.10. to 10.11.1 - I guess - the normally invisible EFI partition appears on the desktop as a regular volume on different machines, if I choose to show the volumes in the finder preferences. 

When I start "First Aid" with Disk utility the EFI partition get ejected, but on the next start they will appear again. I can boot in Recovery Mode and El Capitan seems to work fine (as fine as it can).

But how can I get OS X not to autoload the EFI partition and hide it again?




  Admins Mac Pro:~ admin$ diskutil info /Volumes/EFI
  Device Identifier:        disk0s1
  Device Node:              /dev/disk0s1
  Whole:                    No
  Part of Whole:            disk0
  Device / Media Name:      EFI System Partition
  Volume Name:              EFI
  Mounted:                  Yes
  Mount Point:              /Volumes/EFI
  File System Personality:  MS-DOS FAT32
  Type (Bundle):            msdos
  Name (User Visible):      MS-DOS (FAT32)
  Partition Type:           EFI
  OS Can Be Installed:      No
  Media Type:               Generic
  Protocol:                 SATA
  SMART Status:             Verified
  Volume UUID:              0E239BC6-F960-3107-89CF-1C97F78BB46B
  Disk / Partition UUID:    BF3A02F5-1B7F-4F5C-9E27-2C3378181F53
  Total Size:               209.7 MB (209715200 Bytes) (exactly 409600 512-Byte-Units)
  Volume Free Space:        181.5 MB (181542912 Bytes) (exactly 354576 512-Byte-Units)
  Device Block Size:        512 Bytes
  Allocation Block Size:    512 Bytes
  Read-Only Media:          No
  Read-Only Volume:         No
  Device Location:          Internal
  Removable Media:          No
  Solid State:              No
Since El Capitan this is the behavior of Workgroupmanager for local accounts if you enable to manage internal harddrives to be only readable for some users. It doesn't matter which user logs in. If there is only one user managed, the EFI partition will show up on start for all useres. Disabling this in Workgroupmanager again hides the EFI partition, too. 
Since Workgroupmanager was lastly updated on Mavericks it is still possible to manage e.g. USB shares to be only readable without having to install a OSX Server, as there is no on board solution for managing user accounts more differentiated than with System preferences.