topic Re: SAN switch path problem ? in HPE EVA Storage

SAN switch path problem ?

Shah Gaurang B. — Thu, 27 Oct 2005 11:59:39 GMT

Hi,
In my network i have 2 SAN switch with 2 hba and 1 VA-7110 storage (7 disk encloser)with raid 1+0 . VA both controllers are connected through hba & switch as a redundacy path.

Now problem is i replaced SAN switch (model 2/12 open fabric edge switch)due to prob. in switch .Now through ioscan -funC disk command few path of disk showing no_hw result but in off condition of 2nd working switch, replaced switch is working fine .so no mistake in connectivity or in path but show how to check that on which path new switch is working ? old path showing as a error .in ioscan command so manny path displyed on screen .

Re: SAN switch path problem ?

Charles McCary — Thu, 27 Oct 2005 12:27:28 GMT

Have you checked connectivity between all devices? Are all the lights on?

Re: SAN switch path problem ?

Slawomir Gora — Thu, 27 Oct 2005 13:16:06 GMT

Hi,

maby path to disks have changed after switch replacement (check if there are some new devices) and maby you need to run vgexport/vgimport for vg group. Try to check number of disks after switch replacement.

Re: SAN switch path problem ?

Kofi ARTHIABAH — Thu, 27 Oct 2005 13:46:53 GMT

A couple of things come to mind:
1. Have your configurations from the running switch been copied over to the replaced switch. I am thinking that maybe your new switch does not have the requisite zoning information?
2. You can verify which paths are showing as NO_HW as follows:
- run ioscan -fnC disk
Note the HW Path (its the third column of) something like 0/10/0/ etc. for the devices that are reporting NO_HW.
If all the NO_HW devices are going through the same path (and that path is the new switch) then chances are that your zones may not be configured on the new switch.
You can also try
for i in /dev/td?
do
fcmsutil $i
done
you should check the status - things like link speed, Number of active logins etc. should give you an idea if your HBA is "seeing" physically and logically, the switch/disks

Good luck.
Kofi

Re: SAN switch path problem ?

Torsten. — Thu, 27 Oct 2005 14:03:41 GMT

Did you check all settings for the new switch? Zoning and

*Domain ID*

are really important.

Re: SAN switch path problem ?

Shah Gaurang B. — Fri, 28 Oct 2005 04:19:40 GMT

Thaks for prompt reply to all .
i test zoning is ok and even in off condition of working switch second (replaced) switch is working fine only problem is why it shows no_hw when i applied command ioscan -funC disk

and how to on which path it is connected ?

Re: SAN switch path problem ?

Torsten. — Fri, 28 Oct 2005 05:50:31 GMT

The hw path in ioscan consists of the internal path in the server, the switch domain id and the switchport, on which the storage is connected. You can plug the cable from server to switch wherever you want, but you must always use the same port for the cable between switch and array.
Perhaps it will be helpful if you post a ioscan -fn.

Re: SAN switch path problem ?

Shared TSS Unix — Fri, 27 Oct 2006 16:15:40 GMT

Since the device numbers would change while you change the switch, you may want to do
vgscan -a -v
and then
for i in /dev/vg*
do
vgchange -a y $i
done

Use pvchange, vgreduce, vgextend commands to do load balancing on HBA's if necessary.

Re: SAN switch path problem ?

avik — Sun, 29 Oct 2006 01:26:41 GMT

this is expected, if the path thro which the luns are accessed is not available later. since you are able to access the lun thro' new path (of the new switch), the non existing device path/file may be deleted using rmsf command.