Saturday, June 26, 2010

Operations Manager Efficiency Plugin

After the release of DFM 3.8.1 NetApp has released a nice little plugin for DFM called as ‘Operations Manager Storage Efficiency Dashboard Plugin’. Though quite a long name but it’s good, it cleverly uses DFM database to pull storage utilization and presents the information in nice flash based webpage.

It’s useful when you have to show higher management current storage utilization and saving came from NetApp thin provisioning, dedupe, flexclone and other stuffs and goes very well with NetApp’s storage efficiency mantra. The best part is, after you install the plugin you don’t have to anything and you can access it from anywhere in network without installing any software, however there isn’t a simple way to reach the page even after you are right inside OM webpage as there is no link pointing to dashboard, so you have to remember the location to access it later or for people like me bookmark in your browser.

The most common problem arising from this is due to lack of foresight while creating the plugin. Here’s what I mean to say. Usually we install DFM server on c:\ and move all perfdata, DB, script folder and other bits and pieces to a different drive for easy backup or in the case of cluster, for clustering setup and here script falls apart. Script expects that it is sitting in its default location and web folder is sitting right next to it, so it acts accordingly whereas in real situation web folder is on c:\ and script is in some other volume.

Now there isn’t any way to rectify the behaviour of script or web server, as apache running on DFM can’t be configured to use any folder other then the one sitting inside the installation directory (AFAIK) and no switches are provided in script to tell him the location of original web folder where he needs to copy its content.

So in nutshell even though script executes and copies all the files required for showing the dashboard it’s useless unless you figure out by yourself what’s going wrong and why not the page is showing in your browser.

Overcoming this limitation is easy enough for folks those who are on Unix environment as creating an alias to original web folder makes everything working fine but for windows folks like me creating a shortcut doesn’t works.

So here’s the way to correct the problem.

Download the plugin from now toolchest. Extract the zip and edit file ‘package.xml’, change the string “dfmeff.exe” to “dfmeff.bat”, next you have to create a new batch file in called “dfmeff.bat” with below contents.

@echo off
xcopy D:\DFM\web\*.* "C:\Program Files\NetApp\DataFabric\DFM\web" /Q/I/Y/R

Obviously you have to change the path as per your installation however once you have created the batch file and added its reference in xml file you are good to go, just zip it again using any zip software and use the new zip file as plugin source for installation in DFM.

Just noticed a video showing features of plugin on netapp community site

Monday, June 7, 2010

Which is faster, NDMPcopy or vol copy?

After posting my last post I got few mails asking, amongst ndpmpcopy and vol copy, which one would be faster?

Only if I have to count speed then vol copy, because it copies blocks directly from disk without going through FS, however I think it’s well suitable if you want to migrate a volume.

  • CPU usage can be throttled
  • Source volume snapshot can be copied
  • Simultaneously 4 copy operations can be started
  • Once started it goes to background and you can use console for other purpose 

  • Destination can’t be root volume
  • Destination volume should be offline
  • All data in destination volume will be over-written
  • Destination volume size should be bigger or equal to source
  • Single file or directory cannot be specified for copy operation
  • Both the volumes should be of same type; traditional or flexible
  • If data is copied between two filers both filer should have other filer’s entry in /etc/hosts.equiv file and loopback address for itself in /etc/hosts file 

However for copying data between two filers for test or any other purpose ndmpcopy is more suitable because it gives you additional control and less restrictions, which is very useful.

  • Little or no CPU overhead
  • Incremental copy is supported
  • No limitation on volume size and type
  • No need to take destination volume offline
  • Single file or directory can also be specified
  • No file fragmentation on destination volume as all data is copied sequentially from source volume so improved data layout
  • No configuration is required between two filers and username and password is used for authentication

  • Snapshots can’t be copied from source
  • Console is not available till the time copy operation is running so no multiple ndmpcopy operations
  • If lots of small files has to be copied then copy operation will be slower 

So as you have seen both are well however one can’t be replaced for other and both have their usage for different purposes.