Adjusting the Operating System Shared Memory Parameters

Adjust shared memory segments if Adaptive Server cannot obtain large memory as a single segment, or if Backup Server stripes fail due to insufficient segments.

Depending on the number and types of devices used for backup (dump) and recovery (load), you may need to adjust the shared memory segment parameter in the operating system configuration file to accommodate concurrent Backup Server processes. There are six default shared memory segments available for process attachments.

If any reconfiguration through sp_configure requires additional memory, Adaptive Server allocates shared memory segments after start-up. To account for these additional segments, allocate the maximum memory available to Adaptive Server by using the allocate max shared memory configuration parameter. See the System Administration Guide.

No special steps are necessary to configure for shared memory, however, you can modify the global ulimit information in /etc/security/limits with the following, in case the default hard limits for file sizes (fsize) and numbers of files (nofiles) may be too low:
- ulimit -d – displays current process execution memory limits
- ulimit -d unlimited – sets process execution memory limits to unlimited
You can also edit /etc/security/limits by changing the default data value to "-1":
```
default: 
    ...
    data = -1 
    ...
```