Accessing objects across nodes and owners

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Three function calls support cross-node, cross-owner access on the same platform: dsmSetAccess, dsmDeleteAccess, and dsmQueryAccess. These functions, along with the -fromnode and -fromowner string options that are passed on dsmInitEx, permit a complete cross-node query, restore and retrieve process through the API.

For example, User A on node A uses the dsmSetAccess function call to give access to its backups under the /db file space to User B from Node B. The access rule is displayed as:

ID	Type	Node	User	Path
1	Backup	Node B	User B	/db//

When User B logs on at Node B, the option string to dsmInitEx is:

  -fromnode=nodeA -fromowner=userA

These options are set for this session. Any queries access the file spaces, and files of Node A. Backups and archives are not permitted. Only query, restore, and retrieve processes are permitted from the file spaces for which User B has access. If the application tries to execute any operation using a dsmBeginTxn (for examples, backup or update) while signed in with a -fromnode or -fromowner option set, then the dsmBeginTxn fails with the return code DSM_RC_ABORT_NODE_NOT_AUTHORIZED. See the individual function calls and dsmInitEx for more information.

Tip: On UNIX and Linux® you can specify –fromowner=root in the option string that is passed on the dsmInitEx function call. This permits non-root users access to files that the root owns if a set access was performed.

Use the asnodename option on the dsmInitEx option string with the appropriate function to back up, archive, restore, retrieve, query or delete data under the target node name on the IBM® Storage Protect server. See Backing up multiple nodes with client node proxy support for information on enabling this option.