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vforde
2 Iron

SRDF Compression

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Hi,

How do you check if software rdf compression is on? symcfg -RA all list -v shows the "RDF HW Compression Supported:" but i see no mention of software compression.

I understand that SRDF compression can be done at the hardware and software level. The software compression is Enginuity based srdf compression introduced 5874 Q42009.

Have i missed a beat somewhere?

Thanks,

Victor

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sauravrohilla
3 Cadmium

Re: SRDF Compression

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From SRDF CLI guide,

To determine if SRDF software and hardware compression is enabled for an SRDF group,

issue the symcfg list -rdfg XX command

regards,

Saurabh Rohilla

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sauravrohilla
3 Cadmium

Re: SRDF Compression

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From SRDF CLI guide,

To determine if SRDF software and hardware compression is enabled for an SRDF group,

issue the symcfg list -rdfg XX command

regards,

Saurabh Rohilla

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vforde
2 Iron

Re: SRDF Compression

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Hi,

Thanks so I was checking the channel and not the group, so it is enabled at the the SRDF group level.

Is the software compression feature included as part of the SRDF license or is it a seperate license?

Thanks,

Victor

sauravrohilla
3 Cadmium

Re: SRDF Compression

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Good question. All I can tell its not seperately licensed so it has to be part of either SRDF base or SRDF A license.

regards,

Saurabh

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vforde
2 Iron

Re: SRDF Compression

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OK thanks. The symcfg -rdfg x list here shows a fixed value of 10 for LL (which it may do for >= 10) so if it was on it wouldn't have a noticable performance difference I guess or else you get your metrics somewhere else...

That's answered my initial question how to check for it and I have looked up how to set it.  I need to research where to get metrics to help determine when it should be on as it is not on by default.

Thanks for you help

Victor

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Zikas
3 Argentium

Re: SRDF Compression

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Hi,

With Vmax, the RDF compression should be controlled via solutions enabler. The new hardware and code supports both hardware and software compression.

To enable hardware compression you must use following command:

set rdf group x rdf_hw_compression=Enable

To enable software compression you must use again SYMCLI to define the SWCP policy (Sync/SRDFA/Adaptive compression).

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StuartA58
3 Argentium

Re: SRDF Compression

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Zikas:

I'm just about to do this on our VMAX.  Questions:

1.  So, I guess the RDFG has to already exist (that would make sense).

2.  Is this an online operation?  I can do it right in the middle of the day?  I don't have to suspend the group or take it out of "async/consistent" status?

3.  I only have to do it on the "send" end?

     Stuart

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Zikas
3 Argentium

Re: SRDF Compression

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Hello Stuart and Happy New Year,

1. RDFG group must be already existed.

2. You can do this online on the software group (device group) but at the customer that i have done it, is using SRDF/S and i suspended the group just for "the fear of punishment".

3. Yes

John

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StuartA58
3 Argentium

Re: SRDF Compression

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John:

thanks for quick reply!

FYI, I just did a test case online during the day with no problem.  You don't have to suspend async.  It worked just fine.

I'm going to do the "big" change this weekend with production RDFGs.

   Stuart

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Zikas
3 Argentium

Re: SRDF Compression

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Hi Stuart,

i am glad to help you.

I wish you good luck, but don't worry, everything will go fine.

It is straight forward job.

In any case, more or less, i am checking my email very often (Greek local time now is 16:46), so i have an eye on my email during the weekend.

John

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