Hello Chris,
at first you need to identify where the time is spent in the whole I/O stack
(e.g. I/O scheduler, SCSI, etc.).
For example you can do that with blktrace on Linux:
http://www.fis.unipr.it/doc/blktrace-1.0.1/blktrace.pdf
Anything further is related to this drill-down outcome :-)
Best Regards
Stefan Koehler
Independent Oracle performance consultant and researcher
Website: http://www.soocs.de
Twitter: @OracleSK
Chris Stephens <cstephens16@xxxxxxxxx> hat am 7. Mai 2018 um 15:59--
geschrieben:
We have a new 5 node 12.2 RAC system that is not performing the way we want.
The glaring issue is that "db file sequential read"'s are taking ~10ms.
before i lob this over to the storage administrators, are there any possible
areas in the clusterware/database configuration that I should investigate
first? i have root access to all of the nodes. is there any information i can
collect that would expedite the process of figuring out why we have such slow
I/O times?
slow i/o was discovered by running slob. if you don't know about that tool,
you should. we all owe kevin a debt of gratitude. ;)
if nothing else, i hope to learn a little more about storage than i currently
know (which isn't much).
thanks for any help.
chris
