8464axExamples.fm Draft Document for Review February 7, 2020 3:15 pm GLYPH<SM590000> With this flag ON (one cluster is temporarily unavailable), the application is still able to  mount volumes to the remaining cluster. Copies are rolled back to Synchronous-Deferred  mode, which is the highest priority of deferred copy queue. The composite library enters  the Synchronous Deferred State, exiting from it only when all Synchronous-Deferred  copies have been run in all distributed libraries of the grid.  GLYPH<SM590000> For TVC selection for scratch mounts, each cluster has a defined number of virtual drives.  If a mount occurs, a virtual drive is selected. The Override policy for Fast Ready  Categories ensures that the local TVC is selected. No remote mount occurs. MCB has a parameter setting of R/R: GLYPH<SM590000> Data in cache: At RUN time, a valid copy is in each cache. GLYPH<SM590000> If one cluster is not available, the copies are set to immediate copy deferred and run as  soon the cluster is available again. GLYPH<SM590000> Mount behavior in normal conditions: Controlled by customer (JES3/JES2). GLYPH<SM590000> Mount behavior in outage conditions: If one cluster is not available, the mount is still run. GLYPH<SM590000> TVC selection for scratch mounts: As described in MCA, the local TVC is used. No remote  mount occurs.  MCC has a parameter setting of R/D: GLYPH<SM590000> Data in cache: At RUN time, a valid copy is in one cache, and the other cluster has no valid  copy. The deferred copy is run later. GLYPH<SM590000> Mount behavior in normal conditions: Controlled by customer (JES3/JES2). GLYPH<SM590000> Mount behavior in outage conditions: If one cluster is not available, the mount is still run. GLYPH<SM590000> TVC selection for scratch mounts: As described in MCA, the local TVC is used. No remote  mount occurs.  MCD has parameter settings R/N and N/R: GLYPH<SM590000> Data in cache: At RUN time, only one copy of data in the chosen cluster is available. No  copy is run to the other cluster. GLYPH<SM590000> Mount behavior: If the cluster is not available, the mount is still run.  Note:  Because a copy is located only within one of the two clusters, private mounts  might fail in an outage if the targeted volume is not in the cluster that remains available. GLYPH<SM590000> TVC selection for scratch mounts: As described in MCA, the local TVC is used. No remote  mount occurs.  Important:  These MCs are necessary for BVIR processing, DR volume testing, and Copy  Export runs.  Special considerations for non-Fast Ready mounts and Copy Policy Override  Assume that you have a private non-Fast Ready mount for a logical volume. MC C with R/D is  selected. Prefer local cache for non-fast ready mounts is selected on Cluster 1, but not on  Cluster 0.  If Cluster 0 is selected as the virtual drive mount point, the TVC might be selected where a  valid copy exists. That can result in a remote write to Cluster 1, and the data will be in Cluster  1 after RUN. If the data was modified, a copy is processed to Cluster 0 at RUN time. If the  data was not modified, no copy occurs.  894  IBM TS7700 Release 5.0 Guide