Frequently Asked Questions 205
13
Frequently Asked Questions

NDMP

1
Is NDMP a High Availability (HA) protocol? What happens if a backup
session is interrupted due to connection loss?
NDMP is not HA. A session that is interrupted is terminated.
2
How does NDMP work?
At the beginning of the NDMP session, a Fluid File System
(
FluidFS)
snapshot is taken on the target NAS filesystem. This snapshot is then
transferred over to the Data Management Application
(
DMA). At the
end of the session the snapshot is deleted.
3
Are NDMP snapshots special?
No, they are regular one-time FluidFS snapshots.
4
Who provides load balancing?
NDMP has no load balancing built in. Single DMA backing up 10
volumes from single client VIP force all 10 sessions on the same node.
Use DNS round-robin to provide load balancing, by specifying a DNS
name of your NAS appliance in the DMA.
5
Why do I see ndmp_backup_xxxx_nodeX snapshot on my volume?
This is the snapshot taken by NDMP. After a successful backup session,
this snapshot is deleted. If backup session is terminated with an error, the
snapshot may be left in place, and can be safely deleted manually.
6
How many DMAs can run backup at any given time?
Up to 16 DMAs can be set up on PowerVault NX3500. There is no
limit on the number of DMAs taking backup at any point in time.