will oversubscription of NL disks affect the FC disks?

[spchew901]

will oversubscription of NL disks IOPs (over 200 IOPs per disk) affect the performance of the FC disks or the 3Par performance overrall in terms of front end / backend ?

[eve]

YES, oversubscribed NL disks indeed will have an impact on your FC disks.

NL disks are rated for max 75 IOPS. Above and the latencies will increase.
As the system is using a shared data cache architecture, this may have an impact on FC disks too.

[hdtvguy]

We run into this problem from time to time and while in theory it can impact FC we have not seen that. We run into this during backups as the array is getting hammered and the NL in particular. If you are routinely over subscribing your NL I would be curious as to why as if AO is in play it should be moving actively busy blocks to higher tiers over time.

[Richard Siemers]

It also depends on what percentage of NL vs FC you have... if your disk shelf has 9 magazines of NL and just one of FC, I would expect it more likely to be a problem than if you had 1 magazine of NL per shelf with 9 magazines of FC.