\u4eca\u5929\u5728\u770b\u4e00\u4e2ashell\u811a\u672c\u7684\u65f6\u5019\u78b0\u5230\u7684dd\u547d\u4ee4\uff0c\u5728\u90a3\u4e2a\u811a\u672c\u4e2d\uff0c\u8be5\u4f5c\u8005\u4f7f\u7528dd\u547d\u4ee4\u590d\u5236\/\u53d6\u6587\u4ef6\u7684\u524d1024KB\u7684\u5185\u5bb9\uff08\u8be5\u811a\u672c\u7684\u529f\u80fd\u662f\u5220\u9664\u6307\u5b9a\u8def\u5f84\u4e0b\u7684\u91cd\u590d\u6587\u4ef6\uff09\uff0c\u76ee\u7684\u5728\u4e8e\u907f\u514d\u6587\u4ef6\u8fc7\u5927\u65f6\u4f7f\u7528cp\u547d\u4ee4\u800c\u9020\u6210\u7684\u6548\u7387\u964d\u4f4e\u3002\u6700\u5f00\u59cb\u63a5\u89e6Linux\u7cfb\u7edf\u7684\u65f6\u5019\u5c31\u89c1\u5230\u8fc7dd\u547d\u4ee4\uff0c\u4f46\u57fa\u672c\u6ca1\u6709\u7528\u8fc7\uff0c\u8fd9\u6b21\u60f3\u7740\u8981\u4e0d\u4e86\u89e3\u4e00\u4e0b\uff1f\u7136\u540e\u5c31\u6709\u4e86\u4e0b\u6587\uff1a<\/p>\n
http:\/\/search.aol.com\/aol\/search?q=linux+time+dd+command+i%2Fo+speed<\/a><\/p>\n ==<\/p>\n \u529f\u80fd\u8bf4\u660e\uff1a\u8bfb\u53d6<\/strong><\/span>\uff0c\u8f6c\u6362<\/strong><\/span>\u5e76\u8f93\u51fa<\/strong><\/span>\u6570\u636e\u3002<\/p>\n \u8bed\u3000\u3000\u6cd5\uff1add [bs=<\u5b57\u8282\u6570>][cbs=<\u5b57\u8282\u6570>][conv=<\u5173\u952e\u5b57>][count=<\u533a\u5757\u6570>][ibs=<\u5b57\u8282\u6570>][if=<\u6587\u4ef6>][obs=<\u5b57\u8282\u6570>][of=<\u6587\u4ef6>][seek=<\u533a\u5757\u6570>][skip=<\u533a\u5757\u6570>][–help][–version]<\/p>\n \u8865\u5145\u8bf4\u660e\uff1add\u53ef\u4ece\u6807\u51c6\u8f93\u5165\u6216\u6587\u4ef6\u8bfb\u53d6\u6570\u636e\uff0c\u4f9d\u6307\u5b9a\u7684\u683c\u5f0f\u6765\u8f6c\u6362\u6570\u636e\uff0c\u518d\u8f93\u51fa\u5230\u6587\u4ef6\uff0c\u8bbe\u5907\u6216\u6807\u51c6\u8f93\u51fa\u3002<\/p>\n \u53c2\u3000\u3000\u6570\uff1a<\/p>\n bs=<\u5b57\u8282\u6570> \u00a0 \u5c06ibs( \u8f93\u5165)\u4e0eobs(\u8f93\u51fa)\u8bbe\u6210\u6307\u5b9a\u7684\u5b57\u8282\u6570\u3002<\/p>\n cbs=<\u5b57\u8282\u6570> \u00a0\u8f6c\u6362\u65f6\uff0c\u6bcf\u6b21\u53ea\u8f6c\u6362\u6307\u5b9a\u7684\u5b57\u8282\u6570\u3002<\/p>\n conv=<\u5173\u952e\u5b57><\/span> \u6307\u5b9a\u6587\u4ef6\u8f6c\u6362\u7684\u65b9\u5f0f\u3002<\/p>\n count=<\u533a\u5757\u6570> \u4ec5\u8bfb\u53d6\u6307\u5b9a\u7684\u533a\u5757\u6570\u3002<\/p>\n ibs=<\u5b57\u8282\u6570> \u00a0\u6bcf\u6b21\u8bfb\u53d6\u7684\u5b57\u8282\u6570\u3002<\/p>\n if=<\u6587\u4ef6> \u00a0 \u00a0\u4ece\u6587\u4ef6\u8bfb\u53d6\u3002<\/p>\n obs=<\u5b57\u8282\u6570> \u00a0\u6bcf\u6b21\u8f93\u51fa\u7684\u5b57\u8282\u6570\u3002<\/p>\n of=<\u6587\u4ef6> \u00a0 \u00a0\u8f93\u51fa\u5230\u6587\u4ef6\u3002<\/p>\n seek=<\u533a\u5757\u6570><\/strong><\/span>\u00a0 \u4e00\u5f00\u59cb\u8f93\u51fa\u65f6\uff0c\u8df3\u8fc7\u6307\u5b9a\u7684\u533a\u5757\u6570\u3002<\/p>\n skip=<\u533a\u5757\u6570><\/strong><\/span>\u00a0 \u4e00\u5f00\u59cb\u8bfb\u53d6\u65f6\uff0c\u8df3\u8fc7\u6307\u5b9a\u7684\u533a\u5757\u6570\u3002<\/p><\/blockquote>\n \u628a\u7b2c\u4e00\u4e2a\u786c\u76d8\u7684\u524d 512 \u4e2a\u5b57\u8282\u5b58\u4e3a\u4e00\u4e2a\u6587\u4ef6\uff1a<\/p>\n =<\/p>\n \u4fee\u590d\u786c\u76d8\uff1a<\/p>\n =<\/p>\n \u786e\u5b9a\u786c\u76d8\u7684\u6700\u4f73\u5757\u5927\u5c0f\uff1a<\/p>\n \u901a\u8fc7\u6bd4\u8f83\u4ee5\u4e0a\u547d\u4ee4\u8f93\u51fa\u4e2d\u6240\u663e\u793a\u7684\u547d\u4ee4\u6267\u884c\u65f6\u95f4,\u5373\u53ef\u786e\u5b9a\u7cfb\u7edf\u6700\u4f73\u7684\u5757\u5927\u5c0f\u3002<\/p>\n =<\/p>\n \u9500\u6bc1\u78c1\u76d8\u6570\u636e\uff1a<\/p>\n \u6ce8\u610f\uff1a\u5229\u7528\u968f\u673a\u6570\u636e\u586b\u5145\u786c\u76d8\uff0c\u5728\u67d0\u4e9b\u5fc5\u8981\u7684\u573a\u5408\u53ef\u4ee5\u7528\u6765\u9500\u6bc1\u6570\u636e\u3002<\/p>\n =<\/p>\n http:\/\/search.aol.com\/aol\/search?q=linux+get+first+1000bytes+of+a+file<\/a><\/p>\n \u5728\u4e86\u89e3\u4e86\u4e0a\u9762\u7684\u5185\u5bb9\u4e4b\u540e\uff0c\u6211\u66f4\u597d\u5947\u4e86\uff0c\u4e3a\u4ec0\u4e48dd\u547d\u4ee4\u770b\u4e0a\u53bb\u8fd9\u4e48\u597d\uff0c\u73b0\u5728\u4eba\u4eec\u5728Linux\u7cfb\u7edf\u4e0a\u8fdb\u884c\u6587\u4ef6\u590d\u5236\u65f6\u7528\u7684\u90fd\u662fcp\u547d\u4ee4\u5462\uff1f\u96be\u9053\u4ec5\u4ec5\u662f\u56e0\u4e3acp\u547d\u4ee4\u7528\u8d77\u6765\u7b80\u5355\u4e48\uff1f<\/p>\n http:\/\/search.aol.com\/aol\/search?q=Linux+dd+vs+cp+efficiency<\/a><\/p>\n dd works on the file you specify, making it able to copy data between devices<\/span><\/strong>, or from a device to a file<\/span><\/strong>. This is commonly used for moving data if devices specifically are involved (create an iso image from a cd-rom disc for example: dd if=\/dev\/cdrom of=mycdrom.iso), or backup raw devices<\/span><\/strong> (sometimes used in RAC databases: dd if=\/dev\/raw\/raw1 of=device_raw1)<\/p>\n cp is used for duplicating file content<\/span> to a new file or to a new location. things you specifically want there are preservation of ownership, timestamp and mode (rights), and being able to recurse the operation(=being able to copy directories)<\/span>.<\/p>\n<\/blockquote>\n cp\u547d\u4ee4\u662f\u7528\u6765\u590d\u5236\u6587\u4ef6\u5185\u5bb9\u7684\uff08\u540c\u65f6\u4fdd\u7559\u6240\u6709\u8005\u3001\u65f6\u95f4\u6233\u548c\u6743\u9650\u7b49\u4fe1\u606f\uff09\uff0c\u5e76\u4e14\u5141\u8bb8\u9012\u5f52\u64cd\u4f5c\uff08\u65b9\u4fbf\u8fdb\u884c\u6587\u4ef6\u5939\u7ea7\u522b\u7684\u590d\u5236\u64cd\u4f5c\uff09\uff1b http:\/\/search.aol.com\/aol\/search?q=Linux+best+way+to+transfer+files+between+servers<\/a><\/p>\n \u5b89\u5168\u8d77\u89c1\uff0c\u8d70ssh\u534f\u8bae\uff0c\u4e00\u822c\u5c31\u662fscp\u6216\u8005rsync\uff0c\u4f46\u8981\u8bb0\u5f97\u5728\u4f20\u8f93\u4e4b\u524d\u5148\u6253\u4e2a\u5305\u538b\u7f29\u4e00\u4e0b\uff08\u53ef\u4ee5\u5229\u7528\u7ba1\u9053\u907f\u514d\u6389\u4e2d\u95f4\u7684\u4e34\u65f6\u6587\u4ef6\uff09\u3002<\/p>\n There are two ways I usually do this, both use ssh:<\/p>\n or, the more robust and faster (in terms of transfer speed) method:<\/p>\n Read the man pages for each command if you want more details about how they work.<\/p>\n ==<\/p>\n Instead of using tar to write to your local disk, you can write directly to the remote server over the network using ssh.<\/p>\n Any string that follows your “ssh” command will be run on the remote server instead of the interactive logon. You can pipe input\/output to and from those remote commands through SSH as if they were local. Putting the command in quotes avoids any confusion, especially when using redirection.<\/p>\n Or, you can extract the tar file on the other server directly:<\/p>\n Note the seldom-used -C option. It means “change to this directory first before doing anything.”<\/p>\n Or, perhaps you want to “pull” from the destination server:<\/p>\n Note that the <(cmd) construct is new to bash and doesn’t work on older systems. It runs a program and sends the output to a pipe, and substitutes that pipe into the command as if it was a file.<\/p>\n I could just have easily have written the above as follows:<\/p>\n Or as follows:<\/p>\n Or, you can save yourself some grief and just use rsync:<\/p>\n Finally, remember that compressing the data before transfer will reduce your bandwidth<\/strong>, but on a very fast connection, it may actually make the operation take more time. This is because your computer may not be able to compress fast enough to keep up: if compressing 100MB takes longer than it would take to send 100MB, then it’s faster to send it uncompressed.<\/p>\n Alternately, you may want to consider piping to gzip yourself (rather than using the -z option) so that you can specify a compression level. It’s been my experience that on fast network connections with compressible data, using gzip at level 2 or 3 (the default is 6) gives the best overall throughput in most cases. Like so:<\/p>\n \u4eca\u5929\u5728\u770b\u4e00\u4e2ashell\u811a\u672c\u7684\u65f6\u5019\u78b0\u5230\u7684dd\u547d\u4ee4\uff0c\u5728\u90a3\u4e2a\u811a\u672c\u4e2d\uff0c\u8be5\u4f5c\u8005\u4f7f\u7528dd\u547d\u4ee4\u590d\u5236\/\u53d6\u6587\u4ef6\u7684\u524d1024KB\u7684 […]<\/p>\n","protected":false},"author":2,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[23,11,12],"tags":[479,480,448,481],"class_list":["post-2023","post","type-post","status-publish","format-standard","hentry","category-knowledgebase-2","category-linux","category-tools","tag-cp","tag-dd","tag-rsync","tag-scp"],"views":2566,"_links":{"self":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/2023","targetHints":{"allow":["GET"]}}],"collection":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/users\/2"}],"replies":[{"embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/comments?post=2023"}],"version-history":[{"count":0,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/posts\/2023\/revisions"}],"wp:attachment":[{"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/media?parent=2023"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/categories?post=2023"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/ixyzero.com\/blog\/wp-json\/wp\/v2\/tags?post=2023"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}\u793a\u4f8b\uff1a<\/h6>\n
$ dd if=\/dev\/hda of=disk.mbr bs=512 count=1<\/pre>\n
$ dd if=\/dev\/sda of=\/dev\/sda<\/pre>\n
$ dd if=\/dev\/zero bs=1024 count=1000000 of=\/root\/1Gb.file\n$ dd if=\/dev\/zero bs=2048 count=500000 of=\/root\/1Gb.file\n$ dd if=\/dev\/zero bs=4096 count=250000 of=\/root\/1Gb.file\n$ dd if=\/dev\/zero bs=8192 count=125000 of=\/root\/1Gb.file<\/pre>\n
$ sudo dd if=\/dev\/urandom of=\/dev\/hda1<\/pre>\n
$ time sh -c \"dd if=\/dev\/zero of=ddfile bs=8k count=250000 && sync\"; rm ddfile<\/pre>\n
\u53c2\u8003\u94fe\u63a5\uff1a<\/h6>\n
\n
Linux\u4e0b\u83b7\u53d6\u67d0\u6587\u4ef6\u7684\u6307\u5b9a\u4f4d\u7f6e\u7684\u5185\u5bb9<\/h5>\n
\u641c\u7d22\u5173\u952e\u5b57\uff1a<\/h6>\n
\u53c2\u8003\u7b54\u6848\uff1a<\/h6>\n
$ head -c 6000k \/var\/dump.log\n$ dd if=\/var\/dump.log of=\/root\/1024bytes.txt bs=1024 count=1\n$ dd if=infile of=outfile bs=10 skip=1<\/pre>\n
\u53c2\u8003\u94fe\u63a5\uff1a<\/h6>\n
\n
\ndd\u547d\u4ee4\u548ccp\/cat\u547d\u4ee4\u7684\u533a\u522b<\/h5>\n
\u641c\u7d22\u5173\u952e\u5b57\uff1a<\/h6>\n
\u53c2\u8003\u7ed3\u8bba\uff1a<\/h6>\n
\n
\ndd\u547d\u4ee4\u4e00\u822c\u662f\u7528\u6765\u5728\u4e0d\u540c\u7684\u8bbe\u5907\u4e4b\u95f4\u590d\u5236\u6570\u636e\u6216\u5907\u4efd\u539f\u59cb\u6570\u636e\uff08\u65e9\u671f\u7528\u5f97\u8f83\u591a\uff09\u3002<\/p>\n\u53c2\u8003\u94fe\u63a5\uff1a<\/h6>\n
\n
\u5728\u4e0d\u540c\u7684Linux\u670d\u52a1\u5668\u4e4b\u95f4\u4f20\u9012\u6570\u636e\u7684\u6700\u4f73\u5b9e\u8df5<\/h5>\n
\u641c\u7d22\u5173\u952e\u5b57\uff1a<\/h6>\n
\u53c2\u8003\u7ed3\u8bba\uff1a<\/h6>\n
$ scp -r sourcedir\/ user@dest.com:\/dest\/dir\/<\/pre>\n
$ rsync -auv -e ssh --progress sourcedir\/ user@dest.com:\/dest\/dir\/<\/pre>\n
server1$ tar -zc .\/path | ssh server2 \"cat > ~\/file.tar.gz\"<\/pre>\n
server1$ tar -zc .\/path | ssh server2 \"tar -zx -C \/destination\"<\/pre>\n
server2$ tar -zx -C \/destination < <(ssh server2 \"tar -zc -C \/srcdir .\/path\")<\/pre>\n
server2$ tar -zx -C \/destination -f <(ssh server2 \"tar -zc -C \/srcdir .\/path\")<\/pre>\n
server2$ ssh server2 \"tar -zc -C \/srcdir .\/path\" | tar -zx -C \/destination<\/pre>\n
server1$ rsync -az .\/path server2:\/destination\/<\/pre>\n
server1$ tar -c .\/path | gzip -2 | ssh server2 \"cat > ~\/file.tar.gz\"<\/pre>\n
\u53c2\u8003\u94fe\u63a5\uff1a<\/h6>\n
\n