How many devices on EVA4100 loop

[daanj]

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 

[Torsten.]

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.

[daanj]

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?

[Torsten.]

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.

;-)

[Johan Guldmyr]

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

[Sebastian.Koehler]

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