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Maximum Number of LUNs on XP512

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Robin King
Frequent Advisor

Maximum Number of LUNs on XP512

Dows anyone know what the maximum number of LUNS you can allocate with an XP512 is?
13 REPLIES
Victor BERRIDGE
Honored Contributor
Solution

Re: Maximum Number of LUNs on XP512

Hi,
If I remember right, HDS 9960 (equiv. HP XP512)
at full extension (4 chip pair, 32 interfaces ...) You could have up to 8,192 LUNs...
I believe XP512 should be the same...

All the best

Victor
Victor BERRIDGE
Honored Contributor

Re: Maximum Number of LUNs on XP512

Hi again Robin,
I went around www.hp.com/go/storage.. and looked at what HP put for XP512...
I undestand better your question now...
Have a look at:
http://www.hds.com/products/systems/9900/specs/control_frame.html

All the best

Victor
fg_1
Trusted Contributor

Re: Maximum Number of LUNs on XP512

Robin

The max number of lun's on an XP512 is 4096.

This is based on 512 Drives being loaded in your system.
Robin King
Frequent Advisor

Re: Maximum Number of LUNs on XP512

Okay thanks guys.

Can anyone tell me how many LUNs on the XP512, can be remotely copied at any one time.
Victor BERRIDGE
Honored Contributor

Re: Maximum Number of LUNs on XP512

What do you mean by remotely copied at one time?
On a second bay?

best regards

Victor
Robin King
Frequent Advisor

Re: Maximum Number of LUNs on XP512

Sorry it was a bit general.
I'm trying to find this out for a client.

For DR purposes data will be copied off site, using CA (Continuous Access), similar to EMC's SRDF. Apparently there is a maximum number of LUNS that can be copied site to site at any one time.

Rob
Victor BERRIDGE
Honored Contributor

Re: Maximum Number of LUNs on XP512

Frank is correct : 4096 is the maximum Logical device support, since a device has 2 paths...
(true for XP and HDS...)

All the best

Victor
Victor BERRIDGE
Honored Contributor

Re: Maximum Number of LUNs on XP512

Can it wait till tomorrow?
I dont know the answer, so the best would be I call HDS tomorrow morning and ask them...

All the best

Victor
Robin King
Frequent Advisor

Re: Maximum Number of LUNs on XP512

Now that's what I call service.
Thanks for you help Victor.

Robin
Victor BERRIDGE
Honored Contributor

Re: Maximum Number of LUNs on XP512

Till tomorrow you could go to
www.hds.com/pdf/NanoWhtPpr2.pdf
and have a look at NanoCopy White paper, very good reading!

All the best

Victor
Victor BERRIDGE
Honored Contributor

Re: Maximum Number of LUNs on XP512

Hi Robin,
Im having some trouble with a developper and JAVA..
So you will have to wait a bit if you wish a translation (do you?):
Courtesy my dear friend from HDS Jean Schicker:
Bonjour Victor,
Concernant le Remote Copy les choses se passent comme suite:
- Nombre de LDEV par 9900 = 4'096 (une LDEV peut ??tre directement une LUN ou
peut ??tre regroup??e
pour former une LUN avec multiple LDEV, donc si on utilise que des LDEV's
comme LUN le maximum est 4'096 mais
en utilisant des LDEV regroup??s le nombre de LUN est inf??rieur)
- Le 9900 peut faire des copies de LUN (Remote Copy ou Shadowimage)
Remote Copy s'appelle maintenant TrueCopy chez nous et Continuous Access
chez HP
Shadowimage s'appelle Business Copy chez HP
- Remote Copy est la copie d'une LUN vers une LUN dans un autre syst??me,
donc maximum 4'096 si pas de LDEV regroup??s
- Shadowimage est la copie d'une LUN vers une autre LUN dans le m??me syst??me
- Remote Copy est la creation d'une paire entre LUN's (un P-VOL et un S-VOL,
Primary et Secondary)
- Shadowimage est la creation d'une paire entre LUN's (un P-VOL et jusqu'?? 9
S-VOL)
- Shadowimage et Remote Copy peuvent ??tre piloter par des commandes envoy??es
au syst??me par le lien Fibre Channel.
Ceci n??cessite une LDEV comme Command Device, donc le nombre de LUN remote
copi??e diminue
- Remote Copy utilise des liens ESCON ou Fibre Channel
- Le mode de Remote Copy peut ??tre synchrone ou asynchrone
- En mode synchrone, les donn??es sont appliqu??es en m??me temps sur
l'originale et la copie (le serveur patiente)
- En asynchrone les donn??es sont appliqu??e sur l'original et ensuite
envoy??es dans la deuxi??me baie pour ??tre enregistr??es
(le serveur n'attend pas)


N'hesite pas de m'appeler pour d'autres infos.

Bonne journ??e et un excellent weekend



Jean Schicker
Dave Wherry
Esteemed Contributor

Re: Maximum Number of LUNs on XP512

Although there is a maximum, and I do not know what it is, be aware of other factors. Your amount of shared memory and cache will also limit how many concurrent pairs you can have. On my XP256 I had 384MB of shared memory and 8GB of cache. I could only do 60 pairs. I needed to do 64. So, I had to add another 128MB of shared memory.
Is this XP under maintenance with HP? If so call Stress Central and they can give you the exact number.
Vincent Fleming
Honored Contributor

Re: Maximum Number of LUNs on XP512

The maximum number of LDEVs on and XP512 is 4096, and depends only upon the amount of shared memory you have. The number of drives, ACP pairs, and CHIP pairs do not matter. The 4096 is 16 logical control units x 256 LDEVs each.

The maximum number of CA pairs you can create is 4096 as well... so you *can* mirror an entire frame. It is very correct that the amount of shared memory and cache you have can limit this number, so you should check with your HP Mass Storage Technical Consultant as to the required configuration to support the number of pairs you need.

Also note that with large numbers of pairs, you need to properly size your communication links between the XPs. Again, consult HP for help with this.

Good luck
No matter where you go, there you are.