{"id":8497,"date":"2014-02-27T17:18:50","date_gmt":"2014-02-27T22:18:50","guid":{"rendered":"http:\/\/mjtsai.com\/blog\/?p=8497"},"modified":"2014-02-27T17:18:50","modified_gmt":"2014-02-27T22:18:50","slug":"bup","status":"publish","type":"post","link":"https:\/\/mjtsai.com\/blog\/2014\/02\/27\/bup\/","title":{"rendered":"bup"},"content":{"rendered":"<p><a href=\"https:\/\/github.com\/bup\/bup\">bup<\/a> (via <a href=\"https:\/\/alpha.app.net\/cparnot\/post\/23934138\">Charles Parnot<\/a>):<\/p>\n<blockquote cite=\"https:\/\/github.com\/bup\/bup\"><p>Highly efficient file backup system based on the git packfile format. Capable of doing <em>fast<\/em> incremental backups of virtual machine images.<\/p>\n<p>[&#8230;]<\/p>\n<p>It uses a rolling checksum algorithm (similar to rsync) to split large files into chunks. The most useful result of this is you can backup huge virtual machine (VM) disk images, databases, and XML files incrementally, even though they&rsquo;re typically all in one huge file, and not use tons of disk space for multiple versions.<\/p>\n<p>It uses the packfile format from git (the open source version control system), so you can access the stored data even if you don&rsquo;t like bup&rsquo;s user interface.<\/p>\n<p>Unlike git, it writes packfiles <em>directly<\/em> (instead of having a separate\ngarbage collection \/ repacking stage) so it&rsquo;s fast even with gratuitously\nhuge amounts of data.  bup&rsquo;s improved index formats also allow you to\ntrack far more filenames than git (millions) and keep track of far more\nobjects (hundreds or thousands of gigabytes).<\/p><\/blockquote>\n<p>But:<\/p>\n<blockquote cite=\"https:\/\/github.com\/bup\/bup\"><p>bup is overly optimistic about mmap. Right now bup just assumes that it can mmap as large a block as it likes, and that mmap will never fail.<\/p>\n<p>[&#8230;]<\/p>\n<p>Because of the way the packfile system works, backups become &ldquo;entangled&rdquo;\nin weird ways and it&rsquo;s not actually possible to delete one pack\n(corresponding approximately to one backup) without risking screwing up\nother backups.<\/p><\/blockquote>","protected":false},"excerpt":{"rendered":"<p>bup (via Charles Parnot): Highly efficient file backup system based on the git packfile format. Capable of doing fast incremental backups of virtual machine images. [&#8230;] It uses a rolling checksum algorithm (similar to rsync) to split large files into chunks. The most useful result of this is you can backup huge virtual machine (VM) [&hellip;]<\/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":"","apple_news_api_id":"","apple_news_api_modified_at":"","apple_news_api_revision":"","apple_news_api_share_url":"","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":[146,783,377,74],"class_list":["post-8497","post","type-post","status-publish","format-standard","hentry","category-technology","tag-backup","tag-bup","tag-git","tag-opensource"],"apple_news_notices":[],"_links":{"self":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/8497","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=8497"}],"version-history":[{"count":0,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/posts\/8497\/revisions"}],"wp:attachment":[{"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/media?parent=8497"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/categories?post=8497"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/mjtsai.com\/blog\/wp-json\/wp\/v2\/tags?post=8497"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}