Packet differentiation with storage classes

You can configure the store-and-forward facility to handle packets in different ways. Each packet can be assigned to a storage class, and each storage class can have its own storage bay, return bay, and expiration period.

Note: On Linux and the UNIX system, a storage class can be assigned several storage and return bays; in this case, the shipping server uses the size of the packet to select one of the bays. Conversely, several storage classes can share one or more bays.

The default storage class for packets from schema repository and user database replicas depends on the command you are using. The mkorder and shipping_server commands use the -default storage class, which is created when the DevOps Shipping Server is installed. All multiutil commands that accept the -sclass argument use cq_default as the default storage class. Because this storage class is not created during installation, you must create a storage class named cq_default if you intend to use it.

You can use multiple storage classes to segregate the packets for replicas that belong to different clans. By adjusting the operating system permissions on the storage bay directories, you can protect the packets from unauthorized use. You can also use a separate storage class when you use the store-and-forward facility to transfer non-MultiSite files between sites.

If you are using the store-and-forward facility to transport packets from VOB replicas and from Rational® ClearQuest® database replicas, you must use different storage classes. Because the mkorder and shipping_server commands are used for both DevOps Code ClearCase® MultiSite and Rational ClearQuest MultiSite, you must specify the storage class when you use these commands on a packet from a Rational ClearQuest replica. Also, if you do not create the cq_default storage class, you must use the -sclass option in multiutil commands and specify a Rational ClearQuest MultiSite storage class.

Follow these guidelines when you create a storage class:

The storage bay must be unique. Do not use the same name or directory that you use for packets from VOB replicas.
The directory you specify must be on a partition that has enough room for the packets.
Storage class names are case sensitive. Therefore, defining a case convention for all storage classes you create, or using only lowercase letters in names of storage classes is good practice.