There are two potential issues with having any number of flexvols:

Performance DR Capabilities

Performance: Not so much an issue with having too many, as too busy flexvols... Know what your applications are doing and size the underlying disks accordingly. It is possible (with the current versions of ONTAP - future ones _may_ address this) to starve one flexvol due to IO on another one. Having more disks in the aggr will help to address this and depending on the type of data (online transaction vs decision support for example) this may never surface. Plan accordingly based on the type of workload you have!

DR Capabilities: In the rare event that you have an aggr go offline, you will lose access to all underlying flexvols - if this is a concern to you, please place mission critical accordingly. That said, use the imbedded technologies in ONTAP to protect you as much as possible (MPIO, RAID-DP, CFO). Placing separate data sets on multiple aggregates for Business Continuance is probably about as safe as placing the separate data sets on multiple filers - RAID-DP failures are very rare and are not seen in the wild to a great degree.

Hoe this helps...

Glenn

-----Original Message----- From: owner-toasters@mathworks.com [mailto:owner-toasters@mathworks.com] On Behalf Of Skottie Miller Sent: Thursday, January 26, 2006 4:35 PM To: Premanshu Jain Cc: toasters@mathworks.com Subject: Re: Number of flexvols ?

I mis-red this, and my brain inserted the phrase "flex cache vols". Thats been a focus for us lately. so, when someone asks that question, at least one answer's been posted ;-)

As for local resident volumes, "use them instead of qtrees" is what I've heard from NetAPp, which implese "use alot of them".

20 - 30 should not be an issue.

-skottie

Premanshu Jain wrote:

We are ready to roll out flex-vols and are discussing about the

possible

performance impact of having lot of flex-vols on a aggregate. We are talking about having 20-30 flex-vols per aggregate.

Please share your experience/recommendations ?