Continous access

[avamar]

Is there any way in continous access XP to increase the the numbe rof writes betwewen the sites?

If we want to have multiple writes can we have it or we nned to some software like Oracle data writer to incease the numbe rof writes between the sites ?
Although some limit must be decided by link bandwidth etc ,how to utilize maximum ,the continous access XP link between the sites ?


Thanks in advance......

[Peter Mattei]

Usually the bandwidth of the FC interconnect between the XP arrays is not the bottleneck. The important part is the numbers of IO you can handle!

There are many factors that have an effect on CA performance.
First I suggest you read the chapter "Optimizing Continuous Access XP operations and disk array performance" in the CA user guide starting on page 69 in the october 06 edition:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00801872/c00801872.pdf

Then have a look at the XP12000 performance whitepaper on http://h71028.www7.hp.com/ERC/downloads/4AA0-7923ENW.pdf

Things you need to consider: (I am talking XP12000 now)
a single CHIP CPU can do about
- reads 8kB: 26000IOPS Cache only / 3300IOP (5000IOPS with System Mode 498=on) Backend-Cache avoidance (server IO)
- writes 8kB: 12000IOPS Cache only / 3100IOPS Backend-Cache avoidance (server IO)
- as a CA initiator 12000 IOPS
- as a CA target 3000 IOPS

CA scales quite well with the number of CA ports/CPUs and distributes the load over the available links/CPUs.


So the things you have to focus on are CPU load of the XP ports where the write IO comes in!!
If you are using Performance Advisor XP you can monitor the utilization of the individual components like CPUs, links disk groups, cache etc. and see where you have possible contention and need to adjust.

Cheers
XP-Pete