Ubuntu linux option disappeared after upgrading to High Sierra

[hajime]

Hello, I have Mac OS and Windows installed on the same internal drive. Recently, I also replaced the internal DVD drive with another SSD. I installed Ubuntu Linux on this second SSD. After I installed rEFInd, I could choose among Mac OS, Windows 7 and Ubuntu by holding the option key whenever the Mac was booted. It worked for a few weeks but after I upgraded to High Sierra, the Ubuntu selection option disappeared from the screen. Could you please let me know how to get it back? Thanks

 

[casperes1996]

You should've been able to do that without rEFInd... Anyways, is the Ubuntu SSD showing up alright in Disk Utility and whatnot? – Like, it's not the SSD itself that's the problem I take it? What's the output of diskutil list? If you install GDISK and run "sudo gdisk /dev/disk(# of SSD)" then inside gdisk run p and show the output, as well as r then o in GDISK, what are the outputs?

(GDisk can easily be installed with homebrew)

 

[kschendel]

My rEFInd is an older version, so this might not apply, but ... I usually have to re-bless the rEFInd stuff after installing an OS update, even a minor one. Maybe try that.