EMC Disk Cache

[pmwut5]

Sorry if this question has been asked before but I have had several different response from EMC.

How is the disk cache allocated ?

Is it , when the EMC boots it calculates the number of hypers and divides the cache by the number of hypers ? This would mean to achieve best cache performance it would be benefical to stripe data across as many hypers as possible.
or does the EMC dynamically allocate cache depending on activity. In which case how does the symmetrix prevent a host hogging cache?

Regards

 

[rodgerdave]

I am not sure if this answers your question.

The cache does not allow segmentation, it is a globally shared memory.

The cache attaches to channel directors which are connected to the host as well as the disk directors that are attached to the disk.

However.

The symmetrix offers the option of assigning data permanently to cache. The feature perma cache, is for data that is required to acheive reliable, on demand application performance. This is configured by EMC.

Dave