{"id":19531,"date":"2017-11-15T17:02:28","date_gmt":"2017-11-15T22:02:28","guid":{"rendered":"https:\/\/mjtsai.com\/blog\/?p=19531"},"modified":"2021-06-30T16:34:02","modified_gmt":"2021-06-30T20:34:02","slug":"dive-into-apfs","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2017\/11\/15\/dive-into-apfs\/","title":{"rendered":"Dive Into APFS"},"content":{"rendered":"

Tim Standing<\/a> of OWC gave a great presentation about APFS at the MacSysAdmin conference<\/a> in Göteborg (via St. Clair Software<\/a>). Topics include previous Apple file system efforts, the fragmentation caused by copy-on-write, reasons to never use APFS on a spinning hard drive, sluggish performance compared with HFS+, making snapshots with tmutil<\/code> and restoring them using macOS Recovery, and a mysterious 11th hour change to the format.<\/p>\n\n

His SMART Alec<\/a> app also looks interesting.<\/p>\n\n

Previously: Local Time Machine Uses APFS Snapshots<\/a>, APFS Benchmarks<\/a>.<\/p>\n\n

Update (2017-11-16): Edward Marczak<\/a>:<\/p>\n

Funny timing: you posted this an hour after Tim gave an updated version of this talk at @MacTechConf<\/a>. There were significant updates in that month.<\/p><\/blockquote>\n\n

Update (2017-11-20): Howard Oakley<\/a>:<\/p>\n

\n

Tim – an immensely knowledgeable and experienced Mac software engineer, who for more than twenty years has been half of SoftRAID – draws attention to one of the adverse effects of copy-on-write, perhaps the single most important technology behind APFS. Copy-on-write is the heart of snapshots in APFS, its support for versioning, even the increased metadata protection which makes journalling unnecessary.<\/p>\n

I have previously shown<\/a> how copy-on-write works in the context of a single edit, and versioning. Let me illustrate its downside the same way.<\/p>\n<\/blockquote>\n\n

Update (2017-11-27): Lloyd Chambers<\/a>:<\/p>\n

\n

Folder copy performance is pathetic: I observed it as about 100 times slower versus my Mac Pro. This same folder took about 3 seconds on my 2013 Mac Pro, with its SSD which is about 1\/3 as fast as the blazingly fast SSD in the 2017 iMac 5K. Who at Apple thinks this is a win?<\/p>\n

[…]<\/p>

Bottom line: APFS is a substantial performance downgrade on the fastest SSD that Apple ships, which is the ideal claimed use case for APFS.<\/p>\n<\/blockquote>","protected":false},"excerpt":{"rendered":"

Tim Standing of OWC gave a great presentation about APFS at the MacSysAdmin conference in Göteborg (via St. Clair Software). Topics include previous Apple file system efforts, the fragmentation caused by copy-on-write, reasons to never use APFS on a spinning hard drive, sluggish performance compared with HFS+, making snapshots with tmutil and restoring them using […]<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"apple_news_api_created_at":"2018-11-27T19:30:16Z","apple_news_api_id":"4f13a465-00a6-4306-83e4-09962132555e","apple_news_api_modified_at":"2021-06-30T20:34:05Z","apple_news_api_revision":"AAAAAAAAAAAAAAAAAAAAAA==","apple_news_api_share_url":"https:\/\/apple.news\/ATxOkZQCmQwaD5AmWITJVXg","apple_news_coverimage":0,"apple_news_coverimage_caption":"","apple_news_is_hidden":false,"apple_news_is_paid":false,"apple_news_is_preview":false,"apple_news_is_sponsored":false,"apple_news_maturity_rating":"","apple_news_metadata":"\"\"","apple_news_pullquote":"","apple_news_pullquote_position":"","apple_news_slug":"","apple_news_sections":"\"\"","apple_news_suppress_video_url":false,"apple_news_use_image_component":false,"footnotes":""},"categories":[2],"tags":[1395,738,537,184,295,30,1529,2088,174,1398],"class_list":["post-19531","post","type-post","status-publish","format-standard","hentry","category-technology","tag-apple-file-system-apfs","tag-conference","tag-filesystem","tag-fusiondrive","tag-history","tag-mac","tag-macos-10-13","tag-macos-recovery","tag-storage","tag-zfs"],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/19531","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/comments?post=19531"}],"version-history":[{"count":5,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/19531\/revisions"}],"predecessor-version":[{"id":23500,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/19531\/revisions\/23500"}],"wp:attachment":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/media?parent=19531"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/categories?post=19531"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/tags?post=19531"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}