AFM-based Asynchronous Disaster Recovery features
The following sections describe the AFM-DR features.
All AFM features are offered on AFM DR filesets. AFM DR
features include:
- flushPending
- Parallel data transfer
- psnap
- Recovery after MDS failure
- Unavailable secondary
- HSM support
- Disabling AFM
- Working with encrypted files on both sides
- Using AFM with NFS or Native GPFS™ protocols
You can use mmbackup command to back up all files from primary, as all files are in a cached state on the primary fileset. Similar to AFM filesets, IBM Spectrum Protect™ (HSM) can be connected to primary or secondary, or both sides. When HSM is connected to the primary side, set AFMSKIPUNCACHEDFILES yes in dsm.sys file. AFM features such as revalidation, eviction, prefetch, partial file caching, expiration, resynchronization, failover, and showing home snapshots are not offered on AFM DR filesets.
- RPO snapshots
Recovery point objective (RPO) snapshots are peer snapshots that are taken at the same time on the primary and the secondary sides. RPO is disabled by default, and the minimum value you can set is
720 minutes
. You can update afmRPO parameter while creating the primary
to change the interval, or after creating the fileset by using the mmchfileset -p
command with the afmRPO parameter. - Failover to the secondary site
When the primary site stops functioning, all applications must be moved to the secondary site to ensure stability. Run mmafmctlDevice failoverToSecondary -j FilesetName [--norestore |--restore ] to convert the secondary site to the active primary site. - Failing back to the old primary site
This topic lists the steps to bring back the old primary site. - Failing back to the new primary site
This topic lists the steps to configure a new primary. - Changing the secondary site
This topic lists the steps to follow when the secondary site stops functioning. - AFM features on AFM DR filesets
All AFM features are applicable for AFM DR filesets.
Parent topic: AFM-based Asynchronous Disaster Recovery (AFM DR)