I have created the following number LUNs and presented to the hosts.
Qlogic - FCA2214, A6826A, A7538A, driver 8.01.03
EVA GL3 - 4 luns
EVA XL - 11 luns
EVA GL4 - 10 luns
XP12k - 24 luns
XP128 - 14 luns
On my SLES9 SP3 hosts, the OS see all the above luns. multipath.conf blacklisted the 4 GL3 luns. If starting of with blank /dev/mapper directory and boot up the server, 59 dm mapping will be created in the /dev/mapper and this is all good. Let say I created 2 partitions on each above luns (except the GL3 luns) and reboot the host, the host will hang during boot in middle of mapping or shortly after mapping. Disconnect the host from SAN and let it reboot again. Noticed dm mapping is also created for partitions. Delete partitions on some luns, clean out /dev/mapper directory and repeat the boot up process. Somewhere around 95 or less mapping, the host will boot up fine.
Let me know if there are any limitations on number of DM devnodes created for LUNS and partitions? If not any other thoughts will be greatly helpful.
PS: I need to still validate the same on RHEL4 host.
Thanks and regards