Maximum allowable LUNS ID's for all OS

Hello,

You can find this information on the EMC Support Matrix or Elab Navigator on Powerlink. If you can't find exactly what you want, you would probably want to either contact your local EMC support or post to the appropriate storage area. This Cisco area will probably not have the expertise to answer your questions.

Thank you.

you should be able to find this information here:

Home > Support > Technical Documentation and Advisories > Host Connectivity/HBAs > Installation/Configuration

I think this question may receive more answers if placed in a different area of the forums .. The "infrastructure" area deals with switches, not with hosts ..

Even if you received valuable answers here, it's better to move this thread in the "Host Software/Open Systems" folder. This thread will self-relocate itself in a few hours.

for Linux
Limit on SCSI devices
128 for Red Hat or SuSE SLES 7
and 256 for SLES 8

are you sure only 128 for Redhat ?

http://publib.boulder.ibm.com/infocenter/dsichelp/ds8000ic/index.jsp?topic=/com.ibm.storage.ssic.help.doc/f2c_linuxscsilimit_2hsag9.html

thats what i found in
CLARiiON Host Integration and Implementation Student Guide 2007
page 170 in SAN Implementation and Event Monitor

and after viewing EMC® Host Connectivity Guide
for Linux
P/N 300-003-865
REV A08
page 63 Table 11 Maximum SCSI devices
for RHEL3 up to 128
for RHEL 4 and RHEL 5 up to 1024
for SLES 9 and SLES 10 up to 1024

thx alot dynamox ur the man
anyway should we contact EMC Education center ???

The change from 128 to 1024 was the change from kernel 2.4 to kernel 2.6.

The limits in that document reflect the maximum number supported by EMC, not the theoretical maximum number supported by the O/S that Dynamox pointed out...

Hope that clears things up a little

There are hard maximum numbers (which you can get on the support matrix) though keep in mind it can vary based on hardware limitations (HBA limits) as well as specific OS versions which makes this not as straightforward of an answer as you would hope.

The more realistic thing to keep in mind is that most systems can not really handle hundreds of devices very well. You'll run into long scan times and potentially elongated reboot times. For Windows if you go above the number of potential drive letters you have to start messing with mount points which some applications do not handle very well. For UNIX platforms you start adding dozens of devices into single volume groups and you run into slower activation times (this varies), etc.

With Dynamic LUN addressing and LUN Offsetting on the Symmetrix you should be able to force the LUN addressing for any device on a Symmetrix FA to a low enough range for your host to be able to view.

In my opinion you are much better scaling your LUN sizes up (with meta-luns if needed) and keeping to less than a dozen of so LUNs for Windows and in the less than a 50-60 for Linux/UNIX variant. If you have a very large environment that may not be practical - but just my opinion on general rules of thumb.

Do you have any cases where you think you may need more than a 100 devices for any of the OS platforms you listed?