[{"data":1,"prerenderedAt":497},["ShallowReactive",2],{"Categories":3,"NavIndexCategoriesCountFooter":206,"content-\u002F2015\u002F01\u002F01\u002Fwipe-a-fusion-drive\u002F":207},[4,6,7,8,9,10,11,12,13,14,15,16,17,18,19,20,21,22,23,24,25,26,28,29,30,31,32,33,34,35,36,37,38,39,40,41,42,43,44,45,46,47,48,49,50,51,52,53,54,55,56,57,58,59,60,61,62,63,64,65,66,68,70,71,73,74,75,76,77,78,79,80,81,82,83,84,85,86,87,88,89,90,91,92,93,94,95,96,97,98,99,100,101,102,103,104,105,106,107,108,109,110,111,112,113,114,115,116,117,118,119,120,121,122,123,124,125,126,127,128,129,130,131,132,133,134,135,136,137,139,140,141,142,143,144,145,146,147,148,149,150,151,152,153,154,155,156,157,159,160,161,162,163,164,165,166,167,168,169,170,171,172,173,174,175,176,177,178,179,180,182,183,184,185,186,187,188,189,190,191,192,193,194,195,196,197,198,199,200,201,202,203,204,205],{"category":5},"System Administration",{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":27},"Software Development",{"category":5},{"category":5},{"category":5},{"category":5},{"category":27},{"category":27},{"category":5},{"category":5},{"category":5},{"category":27},{"category":5},{"category":5},{"category":5},{"category":27},{"category":27},{"category":27},{"category":27},{"category":5},{"category":5},{"category":5},{"category":27},{"category":27},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":5},{"category":27},{"category":5},{"category":5},{"category":27},{"category":27},{"category":27},{"category":27},{"category":5},{"category":27},{"category":27},{"category":67},"Drones & RC",{"category":69},"DIY Projects",{"category":67},{"category":72},"Photography",{"category":69},{"category":69},{"category":69},{"category":67},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":69},{"category":67},{"category":69},{"category":69},{"category":67},{"category":67},{"category":72},{"category":72},{"category":72},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":5},{"category":5},{"category":72},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":5},{"category":67},{"category":67},{"category":72},{"category":72},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":67},{"category":72},{"category":67},{"category":138},"3D Printing - Laser Cutting - CNC",{"category":138},{"category":138},{"category":138},{"category":138},{"category":138},{"category":138},{"category":138},{"category":138},{"category":138},{"category":138},{"category":138},{"category":5},{"category":138},{"category":27},{"category":27},{"category":138},{"category":138},{"category":72},{"category":158},"Photography,3D Printing - Laser Cutting - CNC",{"category":27},{"category":27},{"category":69},{"category":27},{"category":27},{"category":27},{"category":27},{"category":5},{"category":67},{"category":5},{"category":5},{"category":27},{"category":27},{"category":27},{"category":27},{"category":27},{"category":69},{"category":27},{"category":27},{"category":27},{"category":27},{"category":181},"Home Assistant",{"category":181},{"category":72},{"category":27},{"category":27},{"category":72},{"category":138},{"category":5},{"category":72},{"category":72},{"category":138},{"category":27},{"category":181},{"category":5},{"category":181},{"category":72},{"category":72},{"category":72},{"category":72},{"category":72},{"category":72},{"category":72},{"category":72},{"category":72},{"category":27},194,{"id":208,"title":209,"body":210,"category":483,"date":484,"description":295,"embedImage":483,"extension":485,"image":483,"intro":486,"meta":487,"navigation":488,"path":489,"seo":490,"series":483,"sitemap":491,"stem":492,"tags":493,"__hash__":496},"content\u002F2015\u002F01\u002F01\u002Fwipe-a-fusion-drive.md","Wipe a fusion drive",{"type":211,"value":212,"toc":475},"minimark",[213,218,222,225,228,232,252,255,258,261,265,276,279,282,286,289,315,318,415,418,424,427,444,447,450,454,457,460,464,471],[214,215,217],"h3",{"id":216},"background","Background",[219,220,221],"p",{},"So - my iMac was misbehaving recently and diskutil stated that the disk needed repair.",[219,223,224],{},"This is not usually so big an issue - boot to recovery - start diskutil and repair.",[219,226,227],{},"However - this time it stated that it couldn't repair the disk even from a recovery boot.",[214,229,231],{"id":230},"intention","Intention",[219,233,234,235,245,246,251],{},"Since this has been upgraded a couple of times - I thought I'd make a nice clean start. Created a complete running backup on a USB disk with ",[236,237,244],"a",{"href":238,"rel":239,"target":243},"http:\u002F\u002Fwww.shirt-pocket.com\u002FSuperDuper\u002F",[240,241,242],"nofollow","noopener","noreferer","_blank","SuperDuper",", create a bootable USB disk with ",[236,247,250],{"href":248,"rel":249,"target":243},"http:\u002F\u002Fliondiskmaker.com\u002F",[240,241,242],"Diskmaker X"," (yes - I know you can do it by hand but this makes it a lot simpler) and then wipe the disk completely.",[219,253,254],{},"So - backup made - boot to USB disk. Start disk utility - and get the message that it can't partition the fusion disk (create a new clean partition).",[219,256,257],{},"What to do?",[219,259,260],{},"Googling led me to the following info. It appears that a fusion drive is based on the concepts of a logical volume system similar to lvm - but managed with diskutil.",[214,262,264],{"id":263},"warning","Warning",[219,266,267],{},[268,269,270,271,275],"strong",{},"Note that this will not be recoverable. Make sure of your backups ",[272,273,274],"em",{},"before"," you start.",[219,277,278],{},"While this worked for me - and seems common advice online - it's up to you to decide if you are going to try it - I take no responsibility if it trashes your system (but given that you're attempting it - it's likely trashed at some level already).",[219,280,281],{},"If this doesn't work for you then it'll mean a trip to apple or if you're living somewhere like me - a couple of weeks while the local reseller fixes it for you for a price and they likely won't be able to recover your data - so make sure you have it - time machine, superduper, simple copy to another disk or anything. Also remember to deauth audible\u002FiTunes just in case (reauth them after reinstall).",[214,283,285],{"id":284},"step-1-erase-the-logical-volume-info","Step 1 - Erase the logical volume info",[219,287,288],{},"So - first - find your info - boot into recovery mode and start terminal then run",[290,291,296],"pre",{"className":292,"code":293,"language":294,"meta":295,"style":295},"language-shell shiki shiki-themes github-dark","diskutil cs list\n","shell","",[297,298,299],"code",{"__ignoreMap":295},[300,301,304,308,312],"span",{"class":302,"line":303},"line",1,[300,305,307],{"class":306},"svObZ","diskutil",[300,309,311],{"class":310},"sU2Wk"," cs",[300,313,314],{"class":310}," list\n",[219,316,317],{},"My laptop for example shows:",[290,319,321],{"className":292,"code":320,"language":294,"meta":295,"style":295},"~  » diskutil cs list\nCoreStorage logical volume groups (1 found)\n|\n+-- Logical Volume Group 01A424DC-EC8C-4AD7-89A8-788CC374D849\n    =========================================================\n    Name:         Macintosh HD\n    Status:       Online\n    ...\n",[297,322,323,333,357,363,381,387,399,408],{"__ignoreMap":295},[300,324,325,329],{"class":302,"line":303},[300,326,328],{"class":327},"snl16","~",[300,330,332],{"class":331},"s95oV","  » diskutil cs list\n",[300,334,336,339,342,345,348,351,354],{"class":302,"line":335},2,[300,337,338],{"class":306},"CoreStorage",[300,340,341],{"class":310}," logical",[300,343,344],{"class":310}," volume",[300,346,347],{"class":310}," groups",[300,349,350],{"class":331}," (1 ",[300,352,353],{"class":310},"found",[300,355,356],{"class":331},")\n",[300,358,360],{"class":302,"line":359},3,[300,361,362],{"class":327},"|\n",[300,364,366,369,372,375,378],{"class":302,"line":365},4,[300,367,368],{"class":306},"+--",[300,370,371],{"class":310}," Logical",[300,373,374],{"class":310}," Volume",[300,376,377],{"class":310}," Group",[300,379,380],{"class":310}," 01A424DC-EC8C-4AD7-89A8-788CC374D849\n",[300,382,384],{"class":302,"line":383},5,[300,385,386],{"class":310},"    =========================================================\n",[300,388,390,393,396],{"class":302,"line":389},6,[300,391,392],{"class":306},"    Name:",[300,394,395],{"class":310},"         Macintosh",[300,397,398],{"class":310}," HD\n",[300,400,402,405],{"class":302,"line":401},7,[300,403,404],{"class":306},"    Status:",[300,406,407],{"class":310},"       Online\n",[300,409,411],{"class":302,"line":410},8,[300,412,414],{"class":413},"sDLfK","    ...\n",[219,416,417],{},"Grab the ID from the outermost Logical Volume Group - in this example 01A424DC-EC8C-4AD7-89A8-788CC374D849",[219,419,420,421],{},"Now - we're going to trash it. ",[268,422,423],{},"Really - I mean it: Make sure of your backups.",[219,425,426],{},"Run",[290,428,430],{"className":292,"code":429,"language":294,"meta":295,"style":295},"diskutil cs delete ID\n",[297,431,432],{"__ignoreMap":295},[300,433,434,436,438,441],{"class":302,"line":303},[300,435,307],{"class":306},[300,437,311],{"class":310},[300,439,440],{"class":310}," delete",[300,442,443],{"class":310}," ID\n",[219,445,446],{},"This removes the logical volume group.",[219,448,449],{},"Exit terminal to return to the recovery system.",[214,451,453],{"id":452},"step-2-rebuild-a-functioning-fusion-drive","Step 2 - Rebuild a functioning fusion drive",[219,455,456],{},"Start diskutil from the recovery tool menu - it should show two drives in red - the normal and the SSD parts of the fusion drive. Click on one of them and diskutil should state that it's a damaged fusion drive and offer to fix it. Click fix.",[219,458,459],{},"Once this is done you have a pristine fusion drive ready for install - exit diskutil and start the normal install process.",[214,461,463],{"id":462},"result","Result",[219,465,466,467,470],{},"Well - it worked for me. I can make no promises - but I ended up with a functioning undamaged fusion drive with no repairs needed after running diskutil verify disk. And my iMac is now running ",[272,468,469],{},"much"," faster.",[472,473,474],"style",{},"html pre.shiki code .svObZ, html code.shiki .svObZ{--shiki-default:#B392F0}html pre.shiki code .sU2Wk, html code.shiki .sU2Wk{--shiki-default:#9ECBFF}html .default .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html .shiki span {color: var(--shiki-default);background: var(--shiki-default-bg);font-style: var(--shiki-default-font-style);font-weight: var(--shiki-default-font-weight);text-decoration: var(--shiki-default-text-decoration);}html pre.shiki code .snl16, html code.shiki .snl16{--shiki-default:#F97583}html pre.shiki code .s95oV, html code.shiki .s95oV{--shiki-default:#E1E4E8}html pre.shiki code .sDLfK, html code.shiki .sDLfK{--shiki-default:#79B8FF}",{"title":295,"searchDepth":335,"depth":335,"links":476},[477,478,479,480,481,482],{"id":216,"depth":359,"text":217},{"id":230,"depth":359,"text":231},{"id":263,"depth":359,"text":264},{"id":284,"depth":359,"text":285},{"id":452,"depth":359,"text":453},{"id":462,"depth":359,"text":463},null,"2015-01-01 12:07 +0100","md","How to wipe a fusion drive and then when it has become two partitions - rebuild it back to a fusion drive",{},true,"\u002F2015\u002F01\u002F01\u002Fwipe-a-fusion-drive",{"title":209,"description":295},{"loc":489},"2015\u002F01\u002F01\u002Fwipe-a-fusion-drive",[494,307,495],"fusion","mac","ZPRAylXCeVPVDovDNIusgEhOYvG-UTs2hn_ksXD8584",1778149387926]