2017-03-22 11:41 PM
Hello, I am planning a Volume migration from two older Nodes (FAS3250) to two new Nodes (AFF8040) inside same cluster (ONTAP9.1).
My pan is to start all volume moves at one time (65 Volumes) and set manual Cutover in Maintenance Window.
How many of those Vol moves can be active at the same time? Could not find that information.
10 Volume are above 1 TB used space (20TB)
20 Volumes between 1GB and 1TB (10TB)
35 Volumes below 1G (2GB)
Any help is appreciated.
Solved! SEE THE SOLUTION
2017-03-23 03:48 AM
Found it in TR- 4075
Concurrent Volume Move Jobs
Volume move jobs can run concurrently on the same node or different nodes in a cluster. In general, all jobs serviced by the same controller share the available background resources, which are also shared with other traffic such as SnapMirror. Vol move replication is automatically and transparently throttled during the initial transfer so as not to increase client latency. Therefore, kicking off many volume move jobs in parallel on a single node may not result in the vol moves completing any faster than if multiple batches of volume move jobs were started sequentially.
In Data ONTAP 8.3, an automatic and transparent governor process queues and regulates vol move jobs so that an administrator can initiate as many individual jobs as required. Counters are kept of the number of references to the aggregates owned by each node in all the current vol move jobs, whether as a source or target aggregate. If 8 or fewer aggregate references for a node are involved in the initiated vol move jobs, all jobs will execute uninterrupted. If additional references are made to aggregates on that node in subsequent vol move jobs, these will wait in the setup phase after creating the target volume until one of the executing jobs completes.
2017-03-23 04:07 AM - edited 2017-03-23 04:10 AM
the max of simultaneous volume moves in 8.2 was 16. But concurrent reads (on SAS/SATA disk particularly) could impact severly your 3250. So, moving lot of volumes simultaneously can last long (more than your maintenance window).
Even if you move one by one your volume (max 16) with manual cutover, periodically, any changes made to the source volume are replicated to the destination aggregate, with possible impact on performances.
So, you should move first your volumes with the biggest workload, cut over them during maintenance window if necessary, migrate the LIFs to the 8040, and move other volumes.