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--- cluster:136 [2015/02/10 22:33]
hmeij [How do I ..?]
+++ cluster:136 [2015/08/14 18:10]
hmeij [Moving Content]
@@ Line 28: / Line 28: @@
   * details can be found at [[cluster:135|RSTORE FAQ]]
-==== How do I ..? ====
+==== Moving Content ====
-Well, move stuff around?  Try to avoid programs such as cp, sftp/scp for large content migrations.  The better bet is ''rsync''.  ''man rsync'' for the manual page.
+Our file server is named ''sharptail.wesleyan.edu'' (or ''sharptail'' when on cluster) and it is a 4U integrated storage and server module with an 48TB of disk array. Moving content can severely crippled this server. **/home** is served out by this server to all nodes and if the server can not handle all read/write requests everything comes to a halt. So when moving content please monitor and also observe if others are currently doing something along this line. Here are some tips.
-With rsync you can:
+Do not use any type of copy tool with a GUI or cp/scp or s/ftp. Especially the GUI (drag&drop) are Verboten! These tools are not smart enough and frequently generated blocked processes that halt everything. Use ''rsync'' in a linux/unix environment.
+**Check it out:**
+  * ''ssh sharptail.wesleyan.edu''
+  * is the server busy (''uptime'' loads < 8 are ok)
+  * is there memory available (''free -m'' look at free values)
+  * is anybody else using rsync (''ps -efl | greep rsync'')
+  * is the server busy writing (''iotop'' look at the M/s disk writes(q to quit), values >100-200 M/s bad)
+Three scenarios are depicted below. When crossing the vertical boundaries you are not dealing with local content anymore, thus the content needs to flow over the network. ''rsync'' has many features, one of the important one is the use of a remote shell.
+<code>
+                        |         /home         |    group share     |    some lab location
+some lab location       |                       |                    |
+                  <-----------> sharptail <-----------> Rstore <----------->
+some other college      |                       |                    |
+                        |         /archives     |     lab share      |    some other college
+</code>
+**Some feature examples**
   * preserve permissions, do a checksum between source/destination files, observe what will happen
       * ''rsync -vac --dry-run''
-  * delete files on destination not present on source
+  * delete files on destination not present on source (careful!)
       * ''rsync --delete''
   * throttle the rate of traffic generated, make your sysadmin happy, use
-      * ''rsync --bwlimit=10000''
+      * ''rsync --bwlimit=2500''
-  * and much more ...
+  * use a remote shell form host to host (crossing those vertical boundaries above)
+      * ''rsync  /home/my/stuff/  user@somehost.wesleyan.edu:/home/my/stuff/''
+      * Once contents have been migrated ''rm -rf /home/my/stuff''
+Note the use of trailing slashes, it means update everything inside source ''stuff/'' within target ''stuff/''. If you left the slash off the above command it means put source directory ''stuff/'' inside target directory ''stuff/'' emaning you'll end up with target ''/home/my/stuff/stuff''. You've been warned. USe the dry run option if unsure what will happen.
+** Examples **
+<code>
+# copy from dir stuff lab or remote college to my home on HPCC in tmp area
+rsync -vac --bwlimit=2500 /home/user/stuff user@sharptail.wesleyan.edu:/home/user/tmp/
-So to put it all together, for example move my directory in my home directory named stuff elsewhere
+# sync my stuff folder into /archives inside our HPCC, then clean up
-''rsync --vac --delete --bwlimit=10000 --dry-run /home/username/stuff  rstore0:/data/2/somelabgroup/mydirecotory/''
+rsync -vac --bwlimit=2500 /home/user/stuff/  /archives/user/stuff/
+rm -rf /home/user/stuff/*
-Is output ok? Then run again the ''--dry-run'' option omitted.
+# generate a copy of content on Rstore disk array outside of HPCC but within wesleyan.edu
-Note the lack of source trailing slash but present destination trailing slash; meaning put source inside destination location. If both had a trailing slash it would mean; update source and target at these locations. Beware. ''--delete'' may bite.
+rsync -vac--bwlimit=2500 /home/user/stuff  user@rstoresrv0.wesleyan.edu:/data/2/labcontent/projects/
-Once contents have been migrated ''rm -rf /home/username/stuff''
+</code>

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