Access from BS2000 to Net-Storage

The BS2000 user accesses a file on Net-Storage via DMS interfaces and the net client on the net server in the following steps:

Figure 14: BS2000 access to Net-Storage of type NETSTOR

1. A BS2000 application under the user ID USER1 wishes to access the FILE1 file which resides on Net-Storage and is cataloged in the ABC pubset. This is done via the normal user interfaces of DMS.

2. DMS checks whether the file exists in the user and file catalogs of the ABC pubset. On the basis of the file attributes DEVICE=NETSTOR and VOLUME=ABC@00, DMS recognizes that the file concerned is contained in the ABC@00 directory on the Net-Storage released by the net server (see the section "Connecting Net-Storage to BS2000").

3. The FILE1 file is actually accessed via the BS2000 subsystem ONETSTOR and the net client.

4. The BS2000 subsystem ONETSTOR transforms the BS2000 file access to the corresponding file access in the UNIX file system (UFS) and forwards it to the net client.

5. The necessary preparations must be made on the net server and net client, see section "Preparations on the net server and net client". On the net client the /bs2data1 directory (with the ABC@00 subdirectory) released by the net server is mounted, see section "Connecting Net-Storage to BS2000". File access takes place via NFS in the net server’s UFS.

6. When a node file is accessed, e.g. the file NODE.1, DMS recognizes that a node file (FILE-TYPE=NODE) in the ABC@00 directory on the Net-Storage released by the net server is involved. Node files are contained in a user-specific directory which has the name of the user ID, in this case directory USER1. This directory is created automatically when BS2000 creates the user's first node file.
   To permit a user to work with node files, the POSIX user attributes UserID and GroupID must be entered in the pubset's user entry. For user USER1, for instance, 1005:100 is entered (see figure 15 in chapter "Access of open systems to Net-Storage").