Unisphere for VMAX Tiers Demand Report

Chris,

The "FAST Available" field shows the amount of capacity in a particular Tier that FAST VP is able to use. It's basically the total enabled capacity for all pools in a particular tier (the sum of the capacity of all enabled TDATs), minus the pool reserved capacity (PRC).

You can see the same report with SYMCLI with 'symfast -sid xxx list -demand -tech all -vp'.

Thanks,

- Sean

Thank you very much for the quick response Sean!

This is excellent information and I really appreciate it. I'll pass those details along and see if it answers their questions OK(what you're saying makes sense to me, so hopefully that will clear things up), and will keep you posted.

Kind Regards & Thanks, 

-Chris

Chris,

Something does seem off with the vtier0 report... there was a bug in the demand report in an earlier version of Solutions Enabler (7.6.0 I believe) -- I'm not sure if it affected Unisphere as well. My guess would be that you're either encountering this bug, or there's some stale data that needs to be refreshed in the SYMAPIDB or Unisphere. Might be a good idea to open an SR for this. I'd also check the SYMCLI demand report to see if it reports similar results... the SYMCLI command is 'symfast -sid list -demand -tech all -vp -v'.

Thanks,

- Sean

Hi Sean (and everyone),

Thanks again for the help, and if I could trouble you for just one or two more comments on this, I'd be in your debt.

Working off of the information you provided (thanks again for that), the person I'm assisting is still observing that in the Tiers Demand report, Available (GB) for a tier (vtier0, in this case) is actually larger than the pool (vtier0) itself. To my knowledge as well, there is only one pool which makes up this tier, hence the question.

In our example (please see the attached), vtier0's Free GB + Used GB = 5502GB, yet Available (GB) is 6406GB, and they are wondering why that is, since they've also stated that Pool Reserved Capacity (PRC) = 0GB.

I'm thinking that perhaps the discrepancy exists because of the use of Thin Devices (TDEVs) and oversubscription in the pool? However I'm not quite sure and I'm afraid my research has turned up empty - is there perhaps an easy way to view the amount of enabled capacity for the tier (which you indicated as the starting point for determining "Available (GB)" in the Tiers Demand report)?

Apologies if I've missed something small with regard to FAST or the report, but if you could lend me your thoughts, I'd really appreciate it!

Kind Regards & Thanks Again,

-Chris

Many thanks again for the lightning-fast response Sean!

I'll pursue that and see what I can find out (it's entirely possible that they may be running SE 7.6.0), and I'll also see if we can correllate the same via SymCLI. If we can, then I'll work on getting a Service Request opened with the SSG team.

OK, last question: Is there any chance you might know of a specific hotfix or version of SE where the bug you mentioned was fixed, so I could look it up?

Again thanks so much for the help & Kind Regards,

-Chris

Chris: Minimum PRC you can set is 1

No problem Chris.

The fix is in SE 7.6.1 (and later)… here's the applicable text from the 7.6.1 release notes (in the "Fixed Problems" section):

"The calculation for FAST SG usage and FAST Avail is incorrect in the technology demand report."

Thanks,

- Sean

Awesome - again this is exceptionally helpful information!

Thanks again for your help Sean (and to snalluri as well - I will look into the PRC value as well to make sure it's truly correct). I'll see what I can find out from here, and if needed, we'll open up a Service Request.

Much appreciated once again,

-Chris

FYI ,

Guys,

I was running thru' the same issue and good the issue has already been discussed. I will upgrade my SE soon.

Quick question:
In the FAST VP settings, "pool reserved capacity is set to default 10%",  and If I would like to reduce the pool reserved capacity to minimum for the SSD pool where I'm not going to bound any tdev, shall I do that in the pool properties ?

So it will keep the PRC of FC pool to default 10% and SSD to 1%. Will it work?

Dino

Dino,

In Unisphere for VMAX, yes -- it's in the pool properties screen.

For SYMCLI, you'd use symconfigure to configure the pool_resv_cap setting. For example --

symconfigure -sid 1234 -cmd "set pool Thin_Pool1, type=thin, pool_resv_cap=1;" commit

Ninja edit: Since you're not binding anything to the EFD pool, your proposed settings (10% global PRC, and 1% EFD pool PRC) are also correct.

Thanks,

- Sean