NDMP

NDMP Copy

1 NDMP Copy

Transfers directory trees between filers using NDMP (Network Data management Protocol) 

• Ndmpcopy transfers data between filers/v-filers using the Network Data Management Protocol (NDMP) versions 3 and higher. 
• This process can be thought of as creating a dedicated data pipe between dump running on the source filer and restore running on the destination filer.

1.1 Pre-Requisite

Turn on ndmp by

Filer > ndmpd on

Ping the filers each other and make sure they are reachable

Make sure that the Data ONTAP release on the filers you are using for the copy support NDMP version 3 and/or higher.

Filer >ndmpd version 

For filers running ONTAP version 7.X, change the ndmpd authentication type to challenge 

Filer > options ndmpd.authtype challenge

1.2 How to run ndmpcopy command

From the filer use the following syntax to run the command. 

Syntax: 

ndmpcopy [options] source destination 

Where, source and destination are of the form [filer:]path 

Options: 

-sa username:password This is used for authenticating at source filer 

-da username:password This is used for authenticating at source filer 

-st text | md5 Source filer authentication type 

-dt text | md5 Destination filer authentication type 

-l 0 | 1 | 2 Level 0,1 and 2 copy (default is 0)

-d Debug 

-f Force flag 

-h Help 

Example: 

Filer > ndmpcopy -sa root:password –da root:password  /vol/vol_s 10.100.201.10:/vol/vol_d 

In this example /vol/vol_s directory on the source filer is copied to /vol/vol_d on filer 10.100.201.10 

-sa root:password option is specified to user is root  and password is  “password” for the source user authentication and –da for the same purpose at destination filer, Screen shot.

1.3 Problems Faced and Lessons Learnt

• Initially filer was giving ndmp authentication error, this was fixed by specifying the username and password (-sa and -da) option. 
• NDMP can copy at qtree level, but can not copy individual sub directories 
• Snapshot backups are taken for copying the data and snapshot copy is deleted after transfer is over. 
• No need to restrict the destination volume for copy. 
• Also ONTAP version 7.x requires, ndmpd.authtype set to challenge 

Comparison of vol copy, ndmpcopy and dump/restore

Comparison of vol copy, ndmpcopy and dump/restore

Description	vol copy	Ndmp copy	Dump/restore
Uses Snapshot	Yes	Yes, but snapshot taken by ndmp is deleted after copy is completed	No
Requires rsh access	Yes	No	No
Destination needs to be restricted	Yes	No	Uses tape drive as destination
Requirements Similar Type of Volume	Trad to Trad and Flex to Flex copyonly	Source and destination can be of either flex / Trad Vols	Source could be
Vol size requirement	Destination volume size should be equal or more capacity	No limitation on destination vol size	n/a
Directory level copypossible	No	Yes	Yes