8.19.2015

Shrink/Grow Exadata diskgroups

One of the important tasks that I foresee after an initial Exadata deployment is, mostly prior to DB in production, is to balance/resize the Exadata diskgroups (DATA & RECO).  Generally, the space is distributed as 80(DATA), 20(RECO) or 40(DATA), 60(RECO), depending on the database backup option you choose while deploying. In one of our Exadata setups, we don't need such a huge RECO size, hence, we shrunk the RECO size and increased the DATA diskgroup size. I am pretty sure, many of you might have done and want to do the same. However, shrinking/rebalancing the space is not like a normal ASM resize operation on Exadata, it needs some special consideration and tasks. The following Oracle Support Notes has the better explanation and examples to achieve the task.

Example of dropping RECO diskgroup and adding the space to DATA diskgroup (Doc ID 1905972.1)
NOTE:1465230.1 - Resizing Grid Disks in Exadata: Example of Recreating RECO Grid Disks in a Rolling Manner
How to increase ASM disks size in Exadata with free space in cell disks (Doc ID 1684112.1)
Resizing Grid Disks in Exadata: Examples (Doc ID 1467056.1)