Introduction to administering transient volumes

Transient volumes are the mechanism used to transfer data either generated by or required by the business logic server (TcServer). For example, transient volumes are used during PLM XML export. The file is generated by the TcServer process and written to a temporary area, the transient volume. A ticket for the file in the transient volume is sent to the client that uses the ticket to retrieve the file. In a four-tier configuration, each business logic or enterprise tier server requires a transient volume. It is best practice to have a local FSC on each server to service the local transient volume. Client access to files within a transient volume is dependent on whether clients are running in two-tier or four-tier. The tickets generated for client file access specify either two-tier, or four-tier depending on how the client is connected to the TcServer. Two-tier transient volume file access Clients in a two-tier environment can read and write to the same physical location as the TcServer since they are on the same machine. In this case, the FCC process reads files directly from the transient volume location. File operations need no special fmsmaster_fscid.xml configuration because no FSCs are required to transport the files, and therefore no fmsmaster_fscid.xml configuration is required. Four-tier transient volume file access Clients in a four-tier environment do not have direct access to the transient volume location and must use the FMS system to retrieve files. Therefore, four-tier transient file operations require transient volumes to be configured in the fmsmaster_fscid.xml configuration file. Transient volumes are declared under an FSC with direct access to the files, much like the TcServer process. The FSCs that host transient volumes usually run on the same hosts, under the same user IDs, as the TcServer process. Note The four-tier FSC transient volume server must run with the same user credentials as the pool server and TcServer processes that own the transient volume and all its files. The OS user that FSC and TcServer run with requires read, create, write, and delete permissions in all directories and subdirectories within the transient volume. No other users should have access to this directory. On the server side, two-tier or four-tier configuration makes no difference to how the TcServer process assesses the transient volume.