Known problems on z/OS platforms

This topic contains troubleshooting information for known problems on z/OS® platforms.

IBM HTTP Server requires a nonzero MEMLIMIT parameter. On z/OS V1R10 and later, the default MEMLIMIT parameter of 2 GB is sufficient. However, the default is not sufficient if the z/OS release is older, the MEMLIMIT parameter is reduced in the SMFPRMxx parmlib member, or if the MEMLIMIT parameter is reduced in Job Control Language (JCL). The web server does not start, and you might see a console message:

```
ABEND=S000 U4093 REASON=00000224
```
```
no output from bin/apachectl -v
```
```
bin/ab returns "Killed"
```

For recommended MEMLIMIT values, see Perform required z/OS system configurations.

To determine if any 64-bit programs run on this system, run the following command from a shell prompt: /bin/localedef64.

Expected output:

# /bin/localedef64 
EDC4175 40 Missing output locale name.

Example of a failure:

# /bin/localedef64 
Killed

On z/OS V1R10 and later, the default MEMLIMIT parameter for 64-bit applications is 2 GB per process, which is sufficient for default configurations. If the ThreadsPerChild directive is increased from the default of 100, increase the MEMLIMIT parameter by the same factor. A limit of no fewer than (ThreadsPerChild + 3) × 12 MB is recommended.

Integrated Cryptographic Services Facility (ICSF) is not enabled for AMODE64

z/OS V1R6 might need ICSF 64-bit Virtual Support to use ICSF cryptographic hardware. To issue messages on ICSF status, GSK_SSL_HW_DETECT_MESSAGE=1 is set in bin/envvars.

If ICSF is not enabled for AMODE64, the GSK_SSL_HW_DETECT_MESSAGE will result in the following message logged to the error log at startup:

System SSL: ICSF services are not available

Related tasks

Perform required z/OS system configurations