Veritas Disk Group Limit

[Ricardo R Peirano]

Is there any restriccion about the number of logical devices from an EMC2 i can put together into the same Veritas disk group?

[Robert-Jan Goossens]

Hi,


http://forums.itrc.hp.com/cm/QuestionAnswer/0,,0x929e0559ff7cd4118fef0090279cd0f9,00.html

http://forums.itrc.hp.com/cm/QuestionAnswer/1,,0x9f31c4c76f92d611abdb0090277a778c,00.html

Hope they help,

Robert-jan.

[Ricardo R Peirano]

Robert,
the links you gave me were useful to discover taht there is a big confusion about this topic. I understand the limit of luns you can see from your HP-UX is 128 but I can??t understand why HP support people say that limit is 256.
I heard something about that configuring the FC cards as "fabric" the limit of luns that you can see from your HP-UX will incresed until 65535?

Do you or anybody know something about that?

Regards.

Ricardo.

[Robert-Jan Goossens]

Hi Ricardo,

No I don't, I've searched the Veritas and Sun (i'm using Veritas for Sun) sites to find an answer, but I could not find any hard evidence.

Best to make a call to HP CRC or Veritas support.

Kind regards,

Robert-Jan.

[James Murtagh · Accepted solution]

Hi Ricardo,

Please see this link for more information :

http://www.docs.hp.com/hpux/onlinedocs/netcom/maxlun-whitepaper-v1.0.pdf

I'm going back a bit here, and my SAN experience is mainly with FCAL but I believe HPUX still uses SCSI II protocol so with 16 targets and 8 luns available per channel the total luns per channel will be 128. Of course you can have several channels (controller interfaces).

For Fabrics the node id is made from a 24 bit value, 8 bits for the domain, 8 for the area and 8 for the port. So for lun addressing there are 16 bits available so 2^16=65536.

There are several FC documents available from www.docs.hp.com too, I believe this link discusses addressing :

http://www.docs.hp.com/hpux/onlinedocs/J2635-90014/J2635-90014.html

Regards,

James.

[Ricardo R Peirano]

James,

Thank you a lot. The links you gave me covered all what a wanted to know about this topic. So I could check that I have FC Tachyon XL2 cards with the correct patch applied to my HP-UX and now I just have to talk with my storage provider to see what configuration he is using.

Regards,

Ricardo.

[Martin Johnson]

I'm sure James would appreciate you assigning him some points for his helpful answer as he is getting so close to his graduate cap.

:-)
Marty