My Mac Mini w\/ Fusion Drive (that’s a hard disk and an SSD pretending to be a single volume for better performance) froze and wouldn’t boot. Nothing would make it boot normally again. Recovery mode was OK but couldn’t erase the boot volume nor mount it via Disk Utility (I just got “Unable to delete the core storage logical volume”), so reinstalling seemed impossible.<\/p>\n
Fortunately, I figured out how to do it, using some help from a StackExchange post I found.\u00c2\u00a0See below for the details.<\/p>\n
<\/p>\n
The magic incantation that fixed it was inspired by instructions I found here: <\/p>\n <\/p>\n Here are the steps:<\/p>\n Now you’re free to do whatever you want with this empty disk. In my case, I erased it and created a new partition named “Untitled”\u00c2\u00a0of type\u00c2\u00a0“OS X\u00c2\u00a0Extended (Journaled, Encrypted)” since I want full-disk encryption.<\/p>\n (I tried to call it “Macintosh HD” during the erase step, but Disk Utility failed to erase the disk and complained that name was invalid, so I just left it as “Untitled”, erased the disk, and then renamed it by selecting the Untitled volume in the left-hand-side\u00c2\u00a0list of devices, then clicking on the right-hand-side pane where the name\u00c2\u00a0Untitled was shown and editing it there.)<\/p>\n After this, I quit out of Disk Utility, and ran the “Reinstall Install OS X” app. That does a network install which first required me to log in with my\u00c2\u00a0Apple ID and then downloaded the install files.<\/p>\n <\/p>\n","protected":false},"excerpt":{"rendered":" My Mac Mini w\/ Fusion Drive (that’s a hard disk and an SSD pretending to be a single volume for better performance) froze and wouldn’t boot. Nothing would make it boot normally again. Recovery mode was OK but couldn’t erase the boot volume nor mount it via Disk Utility (I just got “Unable to delete … Continue reading “Fixing a Mac Fusion Drive that Disk Utility can’t erase”<\/span><\/a><\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[11],"tags":[],"class_list":["post-362","post","type-post","status-publish","format-standard","hentry","category-mac"],"_links":{"self":[{"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/posts\/362"}],"collection":[{"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/comments?post=362"}],"version-history":[{"count":8,"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/posts\/362\/revisions"}],"predecessor-version":[{"id":371,"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/posts\/362\/revisions\/371"}],"wp:attachment":[{"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/media?parent=362"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/categories?post=362"},{"taxonomy":"post_tag","embeddable":true,"href":"http:\/\/www.pervasivecode.com\/blog\/wp-json\/wp\/v2\/tags?post=362"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}
\nhttp:\/\/apple.stackexchange.com\/questions\/136590\/how-can-i-delete-a-partition-corestorage-logical-volume-from-the-terminal
\n<\/a><\/p>\nNote: THIS WILL WIPE YOUR HARD DISK<\/strong>. Only do this if you’re completely ready to just burn it all down to the ground and start over with a blank boot disk.<\/span><\/h5>\n
\n
diskutil cs list<\/code> .\u00c2\u00a0Using the mouse, copy the long alphanumeric string that’s on the third\u00c2\u00a0line of output after “Logical Volume Group”. That’s the Logical Volume Group’s universally unique identifier, a.k.a. its\u00c2\u00a0“lvgUUID”.<\/li>\n
\nRun diskutil cs delete FOO-BAR-BIZ-BAZ<\/code>, where FOO-BAR-BIZ-BAZ was your lvgUUID. This deletes the logical volume group. diskutil\u00c2\u00a0will print things about erasing the physical partitions that made up the logical volumes, which in my case were \/dev\/disk0s2 (a 931GB partition on the\u00c2\u00a0internal hard disk) and \/dev\/disk1s2 (a 113GB partition on the internal SSD).\u00c2\u00a0Pay attention to the\u00c2\u00a0names of the\u00c2\u00a0devices that it just liberated on your system, since you’ll use\u00c2\u00a0those device names\u00c2\u00a0in the next step.
\nAt this point you have two\u00c2\u00a0empty HFS+ partitions that are not a Fusion drive anymore, so you’ll want to rebuild the LVG from those two physical partitions.<\/li>\ndiskutil cs create 'Macintosh HD' \/dev\/disk0s2 \/dev\/disk1s2<\/code> and adjust the \/dev\/.. stuff to include the\u00c2\u00a0partitions\u00c2\u00a0that diskutil said it erased & mounted in the prior step.
\nOn my Mac Mini\u00c2\u00a0it took about a minute to finish.
\nAt this point if you run diskutil cs list<\/code> you should see just a\u00c2\u00a0Logical Volume Group and as many\u00c2\u00a0Physical Volumes as you added (which is two in my case, disk0s2 and disk1s2), without any Logical Volumes yet.<\/li>\n
\nDisk Utility should show “Fusion Drive” without any partitions in it, which is expected since we just created the Logical Volume Group without any Logical Volumes in it.<\/li>\n
\nFirst Aid will immediately create a Logical Volume and format it, leaving one big\u00c2\u00a0partition of type”OS X\u00c2\u00a0Extended (Journaled)”\u00c2\u00a0named “Untitled”.<\/li>\n<\/ol>\n