By default, even if they are not specified, the IRISSYS, IRISLIB, IRISTEMP, and IRISAUDIT databases must be local to the instance and mounted at startup.
Examples
In the [Databases] section, each line is a database with arguments Name=a,b,c,d,e,f. Here is an example from Windows:
[Databases]
IRISSYS=c:\InterSystems\IRIS\mgr\
IRISLIB=c:\InterSystems\IRIS\mgr\irislib\
IRISTEMP=c:\InterSystems\IRIS\mgr\iristemp\
IRISAUDIT=c:\InterSystems\IRIS\mgr\irisaudit\
USER=c:\InterSystems\IRIS\mgr\user\
SALES=c:\sales\,SALESERVER
; Database is on instance SALESERVER
BILLING=/usr/billing/,,1
; Database is local and mount required
Example of remote databases without mirroring:
PRDAUDIT=c:\InterSystems\IRIS\mgr\prdaudit\,PRD
PRDDCIFC=\InterSystems\IRIS\mgr\prddata\,PRD
PRDERR=\InterSystems\IRIS\mgr\prderr\,,1
Example of remote databases with mirroring. Note in this mirrored example the two remote databases, both mirrored and nonmirrored, are formatted differently than they would be in a nonmirrored environment.
PRDAUDIT=:mirror:PRDMIRROR:PRDAUDIT,PRD - Mirrored remote database
PRDDCIFC=:ds:PRDDCIFC,PRD - Nonmirrored remote database
PRDERR=\InterSystems\IRIS\mgr\prderr\,,1 - Local database