Re: Database upgrade/move I/O waits performance

Hello Lyall,
regarding to ...

1. Depending on OS (Linux?) and used file system you are currently using page cache (with 224 GB of RAM and SGA_TARGET of 72 GB / PGA_TARGET 12 GB) - if you really got a storage problem you are currently hiding this root cause a bit (or more than a bit depending on your database size) and it will get even worse with DIO (FILESYSTEMIO_OPTIONS=SETALL).
2. Data Stores on VMWare or storage sub-system? Do you use VMDKs or RDM? Do you also gonna split the I/O on different VMDKs in VWware and LUNs in OS guest? That's the problem I mentioned with disk/device queues.

In general there is a VMware best practices guide ( https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/solutions/vmware-oracle-databases-on-vmware-best-practices-guide.pdf & https://www.vmware.com/content/dam/digitalmarketing/vmware/en/pdf/techpaper/vmw-tuning-latency-sensitive-workloads-white-paper.pdf ) but I would suggest that you should figure out and understand the bottleneck in your environment first before making any changes :)

Best Regards
Stefan Koehler

Independent Oracle performance consultant and researcher Website: http://www.soocs.de
Twitter: _at_OracleSK

> Lyall Barbour <lyallbarbour_at_sanfranmail.com> hat am 24. Juli 2019 um 16:36 geschrieben:
>
> Thanks everyone.
> Couple of pieces of new information, if its useful to people.
>  
> 1) FILESYSTEMIO_OPTIONS is still at default "none".  That's being changed tonight during some downtime to SETALL.  I was a bit blown away that that wasn't set by the consulting company doing this upgrade, it was asked for and was set in at least one test system 12.1 databases.
> 2) on a call with the Unix, Storage and VM teams at my company, the amount of Data Stores (??) was brought up compared to best practises.  this system was only set up with one and graphs show a bottleneck for I/O at that point in the process of getting data from Pure Storage to the Oracle database.
>  
> Lyall

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