AO and SSD

[Richard Siemers]

Anyone using AO with SSD?

My intent is for AO to use 100% of my SSD, however it seems to hit a glass ceiling leaving 20% free, only 80% of my SDD is getting used.

I have no alerts or limits on the Tier 0 SSD cpg, any ideas where I need to be looking in order to utilize this last remaining 20%?

Thanks.

[afidel]

Have you looked at the AO job output? It tells you what the threshold it uses for Tier1->Tier0 and Tier2->Tier0 movements as far as latency and IO density are concerned and how many bytes it is going to run each iteration. If it decides to move data it moves it in 16GB chunks (at least in my environment on our 7400 running 3.1.2 MU5) and will move no more than 1TB per day.

[JohnMH]

The 3.2.2 release now provides finer grained control over SSD use in AO environments.

[kk2491]

Hi Richard Sir,

In my case SSD was utilized 100%, we had to install new SSD drives to fullfill the requirement.

But I dont know where we need to check (I dont think there is a option to define the threshold on movement)

May be your VVs are not so hot to move to SSD.

Please do correct me if I'm wrong.

Regards,
KK

[hdtvguy]

I have found AO still to be too much biased toward pushing data down. I am constantly having to deal with my bottom tier being space constrained while my higher tiers are wide open.

[sancommander]

There are some deep commandline options as i know of to "force" data to be moved to SSD based on latency or IOPS, but i have to look for them. Or otherwise, move your VM's with storage vmotion to a SSD VV which is not in a AO config.

I would advice to perform some region-density reports again, and as kk2491 mentioned, maybe there is no reason for some data to move up, so your are nice in balance. That's we're AO is all about.

[cali]

Hi Richard,

with 3.2.2 you can use the AO Premium Mode for this:

Setting up the Premium AO mode will keep the tier0 CPG full regardless of IOPS in order to best utilize the SSDs.
Adaptive Optimization will still respect the CPG space warning or limit settings. The Premium mode will still prevent movement if the destination CPG has high average service times.

[hdtvguy]

Hi Richard,

with 3.2.2 you can use the AO Premium Mode for this:

Setting up the Premium AO mode will keep the tier0 CPG full regardless of IOPS in order to best utilize the SSDs.
Adaptive Optimization will still respect the CPG space warning or limit settings. The Premium mode will still prevent movement if the destination CPG has high average service times.

Now that is what I am looking for! It is about time. Thanks

[Richard Siemers]

Premium mode is exactly what I need. Thanks Cali.

[JohnMH]

3PAR AO Enhancements Review

https://www.youtube.com/watch?v=IyiBMcydDzM