Add and Drop Discs From ASM in a Single Command

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Recently I was tasked to do something that I hadn’t done before. I was required to swap out all the existing discs in the two diskgroups +DATA and +FRA, with minimal downtime. Almost all the places I looked seemed to indicate that I had to add the new discs, re-balance, drop the old discs and re balance again. My colleague, Ian Greenwood, had a much better idea – thanks Ian.

alter diskgroup DATA add disk
'/path/to/disk_1' name DISK_1001,
'/path/to/disk_2' name DISK_1002,
'/path/to/disk_n' name DISK_100N
drop disk
-- This is Spinal Tap!
rebalance power 11;

Then the same again for +FRA and we were done. Well, I say done, once the rebalance had finished we were done, and the Unix team could then remove completely, the old discs. That did need ASM to be bounced though, which was a bit of a nuisance for the (one) database on the server, but the users were happy to let us take it down.

Job done and very little messing around. Sometimes, it’s helpful to look at the Oracle Manuals before hitting MOS or Google (other web search engines are available – but they are not as good!) for hints when you have new stuff to do.

Yes, I spell disc with a ‘c’ while Oracle spell it with a ‘k’. :-)

Tnsnames Checker Utility

I have made available for free a utility that will parse a tnsnames.ora file and report back on anything that it doesn’t like such as duplicate entries, invalid characters, redefinitions of parameters, errors etc etc.

  • Version 0.4 released to_date('07/11/2015', 'dd/mm/yyyy')*.
  • Version 0.3 released to_date('06/12/2014', 'dd/mm/yyyy')*.

*Oracle joke! :-)
*Also avoids Date confusion for my American readers. :-)
Continue reading Tnsnames Checker Utility

Impdp Hangs Importing Materialized Views

A simple exercise to refresh a schema in a test database caused no end of problems when it hung at 99% complete. The last message on screen indicated that it was importing the Materialized Views (yes, with a ‘Z’). After a long time, the DBA running the import killed it, cleaned out, and restarted the whole process. Exactly the same happened. Continue reading Impdp Hangs Importing Materialized Views

Introduction to Oracle Datapump – Part 2

In this, the second part of the Introduction to Oracle Datapump mini-series, we take a look at importing dump files using impdp. If you missed the first part which concentrated on exporting with expdp, have a read of it here. Once again, the following is a quick introduction for people like me – running Oracle on Linux and slightly averse to change! 😉 Continue reading Introduction to Oracle Datapump – Part 2