Max # of disk devices

[NathanK]

We were trying to add a lun to our HP-UX host, but when we do an "ioscan -fnC disk" it doesn't return the new lun. We have 126 disks presented to this host. Are we exceeding a boundary here?

[Devender Khatana]

Hi,

This is not a boundry at all. There seems to be some misconfigured SAN or improper permissions.

HTH,
Devender

[Wayne Patton_1]

Did you add the LUN to the system without rebooting the server? If so make sure you do the following (no need to reboot):

ioscan -f
insf -e

It could be that the device is present, but there is no device file created for it yet.

If you can not see the LUN in output from "ioscan -f" or "ioscan -fCdisk" then there is a SAN config issue.

wayne

[generic_1 · Accepted solution]

Check your zoning.
Make sure you didnt forget to enable the config if you are using Brocade.
do a dmesg and make sure you didnt run out of channels on your system. HPUX has a limit of 255 channels, not to be confused with disks. HPUX has a real problem with the 255 channels and not being able to recycle channels. You can also see the error in syslog.
Double check your zoning.

[NathanK]

Definitely not a zoning or SAN config problem..I can see the host through the fabric from the EVA's SMA. I think Jeff's prior post is hitting on somthing..The channels maybe what our problem is. Any resolution to this?

Nathan

[Steven E. Protter]

HP-UX has a limit of 255 physical volumes per volume group.

That is defined when you create the volume group with the -p parameter.

SEP

[NathanK]

I am not getting far enough to add it to a VG. My problem is that is doesn't show up when using ioscan -fnC disk.

[marie-noelle jeanson_1]

Hi,

The only limit problem I see would be if you had reached the bus limit of 255. This problem is not logged if you hit the limit. It might be caused by having too many stale buses. If it was your problem, you would need to call HP to fix that problem.

Marie.

[NathanK]

Turned out the EVA made about 12 rscsi device files. HP beleives it is a patching issue.