This week has been my first as a consultant for e-dba. One of the big lures of joining was the prospect of working with Exadata, which was never going to happen in my previous position. Also having a new position should hopefully lead to a few more blog posts.
And indeed this week, I have been working on Exadata for a large investment bank in London. There have been a couple interesting little issues that came up that are worth recording here.
Frist off, was an OCR backup issue. As you will be aware, an OCR backup is taken every 4 hours automatically but only a few are stored as for example day.ocr, and week.ocr. These backups cycle round so you only ever have a handful on the filesystem at one time.
However, if you have incorrect permissions on these files, you can find yourself in a situation whereby the old files can’t be overwritten and your filesystem starts filling up with lot of .ocr files in the $GI_HOME/cdata/cluster_name directory.
This is trivial to fix it’s just a permissions issue. So in the directory where the ocr backups are filling up, do:
chown root:root *.ocr
And you are done.
The Other interesting issue that caught me out was with applying Exadata Bundle Patch 11 to 188.8.131.52. We are rolling this across the Exadata estate and while it feels in many ways just like doing a PSU, the catbundle application through me. See if you can spot the difference. This is the insructions I was used to for applying a PSU:
cd $ORACLE_HOME/rdbms/admin sqlplus /nolog SQL> CONNECT / AS SYSDBA SQL> STARTUP SQL> @catbundle.sql psu apply SQL> QUIT
Now compare with the instructions for running catbundle after applying the bundle patch:
cd <ORACLE_HOME>% sqlplus /nolog SQL> connect / as sysdba SQL> @rdbms/admin/catbundle.sql exa apply
Ignoring the fact that it is exa apply, as opposed to psu apply, I would have assumed you would have been able to run it by doing a cd to the rdbms/admin directory and just running @catbundle.sql.
Oh no! That would be too obvious, there are paths to .plb files coded from this location, it all goes horribly wrong if you don’t run from this directory. Ah well you live and learn. I think it showed me the way my brain works, I’m so used to doing it one way, I thought why would it not just work that way with this patch too, in fact I’m so used to running catbundle the other way, I probably did not take in this difference.
This change came in with Bundle Patch 7. Yet another way Exadata is different.
Away from Exadata, it was also great to help out in a small way with an ASM issue so by and large I’ve been thoroughly enjoying my first week.
The other point to make, is in starting a new role, I have a new macbook pro, but getting up to speed with it has been so easy thanks to the cloud. I use dropbox for storing scripts and some sundry other items, and I now have a huge 3700+ set of documents in my evernote account. I dread to think what it would have been like before the cloud.