Usually when you are connected to a EMC Symmetrix array you will install the Solutions Enabler package on your system. Solutions Enabler is basically both a set of tools to help you manage your Symmetrix arrays, as well as an API. The Solutions Enabler basically creates a small database that displays what Symmetrix arrays are connected to the host you are running the software on, the so called SYMAPI database that you will find as a file on your system called “symapi_db.bin”.
Under a normal situation you will run a discover process to initially scan and fill the database with entries. To do that you can issue the command:
This will start the scan operation, and depending on the amount of arrays and the configuration on those arrays you can plan anywhere from just under a minute for a scan up to several minutes. Once the file has been created you could try opening the file and searching for strings inside of the file, and you will find a lot of information about devices, device paths, disk IDs and lot’s more.
Now, in some situations after your array configuration has changed, it is useful to refresh the database file. Under normal circumstances this should all be easily done and without any issues.
However, in some cases your database file might be facing problems, without manifestation in any obvious ways. I have seen cases where new devices would simply not show up. Other examples are error messages about disks that can not be reached because of access control list errors.
If you happen to have some erratic behavior on one of your hosts, you might want to try one thing before creating a service request in Powerlink. You might want to try creating a copy of your database, removing it and then performing a new discover. Some steps to help you do just that:
- Create a backup of your device and/or composite groups using the symdg/symcg commands.
- Rename your old symapi_db.bin to something else.
- Issue a “symcfg discover” to create a new symapi_db.bin
- Import your device and/or composite groups from the backup file(s) you created.
This won’t help you in all situations, but it helped me solve several cases were we were seeing erratic behavior on our hosts, and it might do the trick for you.