Multiple Vault instances on same server with indexerd

In versions of vault prior to 6.1m0p108 it was not possible to have more than one instance of Vault running on the same server if those instances were using indexerd. 

This was because indexerd uses a file on the system as virtual memory, and it was not possible to configure the name and location of that file.  Thus if there were more than one indexerd there would be contention on that file, causing error messages and non-functional indexerd.

NOTE that it's not really recommended to have multiple Vault instances running on the same server in a production environment, but it can be useful in development or pre-prod for testing.

In Vault 6.1M0p0108 and higher, the indexerd module supports the following in server.ini that allows you to control the name of the shared memory so that multiple indexerd can be run concurrently. The setting is
ipcname=name of shared memory file
The default values are:
unix :
For example, you should add something like
in each server.ini
With it being set up in server.ini, you will have to use a separate server directory for each instance of Vault you want to run (that is a good practice in any case).
The programs indexerd, e2serverd, e2loaderd, e2util and indexcheck all will read the local server.ini to determine which shared memory file to use (and thereby which indexerd they will talk to).
This means also that e2util and indexcheck must be run from a command prompt that is at the server directory. If they are run from elsewhere, then they will use the default shared memory file name and try and contact an indexerd that is also using the default shared memory file name.

We highly recommend that if you are going to use this, that all your indexerds on the same machine have specified shared memory files names (do not let it default).
If no indexred is using the default shared memory file name, then there is no risk that e2util or indexcheck will talk to the wrong indexerd.
Environment Details
6.1M0p0108 and higher, all platforms
UPDATED:  September 18, 2017