Good afternoon all,
I got a EMC call staying that they need to IML a director 10B on my symmetrix, but this will cause an outage and impact to the servers connected there; since this will take the director offline
Also the engineer mentioned that this will take at most 15 minutes
My questions are:
Is this safe to do it? what is the process of IML? will this clear the flags already set? how long should it take? what are the actions after IML the director?
thanks a lot for your responses
It means that they are going to recycle your FA, its like a reboot. It wont cause loss of FA bits already set and yes the hosts connected to this FA will see paths connected to this FA going down.
If you have multipaths to your hosts then it wont cause a complete loss of access to the disk but to half of the paths.
It is safe to re-IML directors in Symmetrix. If you have redundant paths, simply failover the path to another directors.
Support will take the director offline and re-IML it. He wil then put the director back online. You can then put the path back online.
re-IML is simply reload the microcode into the director processor.... just like rebooting your PC. Alll director setting wll preserve and will not change.
Also, when support re-IML a director, he will do one processor at a time, both ports "a" and port "b" will be affected.
re-IML should take a few minutes only.
Is this safe to do it? Yes, providing that all hosts mapped to the director have an alternate path.
what is the process of IML? It re-initalizes the microcode on the director.
will this clear the flags already set? No Flags or setting will change.
how long should it take? From just a few seconds up to just a few minutes.
what are the actions after IML the director? If you manually took the paths to the director offline prior to the IML ou will need to bring them back online after the Director comes online.
That's correct it usually takes to about 15 to 30 minutes to do this.
Is this safe to do it?
Absolutely. It is safe to do this. But please make sure that you have the servers are running on redundant paths.
what is the process of IML?
1. Take all ports on director offline.
2. Full IML director.
3. Place all ports on director back to online.
will this clear the flags already set?
No. from my experience, the flags did not clear out. "Can u be a bit more specific when u say flags?"
how long should it take?
Like I mentioned above, this usually takes from about 15 to 30 minutes. The thing is It is usually recommended to do this when there is less traffic on the network. Preferably on the weekends when there are less users on the servers. At times the directors dont go offline immediately and wait for the IOs to go through the other path, only after which it comes down.
what are the actions after IML the director?
There is nothing much an administrator can do apart from checking the list logins of the WWPN of the servers. Please get in touch with the server team ans ask them if things look good from their side. List logins file should look same before IML and after IML.
If something is missing ask the server team to maybe rescan. This might help the server look the paths.
Ask the EMC personnel to have a look at the logs from their end and see if they are seeing any memory leak. If the logs are clear then it's all good. Else EMC may recommend a hardware replacement.
Please let me know if I am wrong and correct me.