IBM XIV Storage System Copy Services and Migration

Once the sync is complete it is time to delete the migrations. Do not leave the migrations inplace any longer than they need to be. We can use multiple selection to perform the deletion,as shown in Figure 7-32, taking care to delete and not deactivate the migration.Figure 7-32 Deletion of the synchronized data migrationNow at the ESS 800 Web GUI we can un-map the three ESS 800 LUNs from the Nextra_Zaphost definitions. This frees up the LUN IDs to be reused for the next volume group migration.After the migrations are deleted, a final suggested task is to re-size the volumes on the XIV tothe next 17 GB cutoff. In this example we migrate ESS LUNs that are 10 GB in size. However,the XIV commits 17 GB of disk space because all space is allocated in 17 GB portions. Forthis reason it is better to resize the volume on the XIV GUI from 10 GB to 17 GB so that all theallocated space on the XIV is available to the operating system. This presumes that theoperating system can tolerate a LUN size growing, which in the case of AIX is true.We must unmount any file systems and vary off the volume group before we start. Then wego to the volumes section of the XIV GUI, right-click to select the 10 GB volume, and selectthe Resize option. The current size appears. In Figure 7-33 the size is shown in 512 byteblocks because the volume was automatically created by the XIV based on the size of thesource LUN on the ESS 800. If we multiply 19531264 by 512 bytes we get 10,000,007,168bytes, which is 10 GB.Figure 7-33 Starting volume size in blocksWe change the sizing methodology to GB and the size immediately changes to 17 GB, asshown in Figure 7-34. If the volume was already larger than 17 GB, then it will change to thenext interval of 17 GB. For example, a 20 GB volume shows as 34 GB.Figure 7-34 Size changed to GBChapter 7. Data migration 239