wsadmin jython scripting installing RAR

I'm using the following script to install a RAR

NODE='test' # node name
CELL='test_cell'
RARFILE='/tmp/ims91015b.rar'
RARNAME='IMSconnect'
RARDESCRIPTION='IMSConnect Rar'

option = []

option ='[-rar.name RARNAME -rar.desc RARDESCRIPTION]'

AdminConfig.installResourceAdapter(RARFILE, NODE, option)

but get the following error

WASX7209I: Connected to process "dmgr" on node WASDmgr_IST06 using SOAP connector; The type of process is: DeploymentManager
WASX7017E: Exception received while running file "test.jy"; exception information: com.ibm.websphere.management.exception.ConfigServiceException
javax.management.MBeanException
com.ibm.websphere.management.exception.AdminException
com.ibm.etools.archive.exception.OpenFailureException: com.ibm.etools.archive.exception.OpenFailureException: IWAE0037E Could not open /tmp/ims91015b.rar

the RAR is in /tmp/ and has the correct permissions. The RAR is not corrupt, I can install using the webadmin without issue....

Any Ideas?