topic Re: How many devices on EVA4100 loop in HPE EVA Storage

How many devices on EVA4100 loop

daanj — Thu, 02 Feb 2012 17:55:58 GMT

Hello.

I'm looking for information how many devices (disk encl) can be on EVA4100 loop without loop switches. In theory 4 but I've seen eva4100 with 5 disk encl on a loop.

Can 8 enclo be put on the loop of EVA4100? Will it work?

Regards
Daan

Re: How many devices on EVA4100 loop

Torsten. — Thu, 02 Feb 2012 18:57:01 GMT

Look at "Family Information" here

http://h18000.www1.hp.com/products/quickspecs/12745_div/12745_div.html

maximum of 56 drives for EVA4100.

The only difference to a 6100 are the switches. With switches (as an EVA6100) maximum is 112 disks.

Re: How many devices on EVA4100 loop

daanj — Thu, 02 Feb 2012 19:30:55 GMT

I know all theory but I've seen eva 4100 with 5 disk shelves on the loop and it worked without any problems. It's not supported but is it possible to put 8 dis encl on the eva4100 loop?

Re: How many devices on EVA4100 loop

Torsten. — Thu, 02 Feb 2012 19:36:08 GMT

I'm sure you know the story about supported vs. unsupported ... ?

Maybe it works with 20 shelfs and only a couple of disks... today, but not tomorrow.

Once your data is gone, someone will ask if YOU built this unsupported config.

;-)

Re: How many devices on EVA4100 loop

Johan Guldmyr — Fri, 03 Feb 2012 06:35:32 GMT

You can't have more than 126 devices on one loop (ALPA addressing limitation). Fewer on the same loop == better performance.

Re: How many devices on EVA4100 loop

Sebastian.Koehler — Fri, 03 Feb 2012 17:01:46 GMT

Always remember why Compaq/HP has introduced loop switches for EVA5000. They had serious trouble with a more than 4 shelfs / 56 disks per loop. It will work, but you put availability and your data at risk. If you need more disks, purchase an upgrade kit to EVA6100. (which includes loop switches)

Regards,
Sebastian