Kernel parameters

Red Hat Enterprise Linux 8.6 LPAR mode z/VM guest

If the HMC media device driver has been compiled into the kernel, you set the cache size by adding the hmcdrv.cachesize= parameter to the kernel parameter line.

Figure 1. hmcdrv kernel parameter syntax

1 
2.1!  hmcdrv.cachesize=534288
2.1  hmcdrv.cachesize=<size>

where <size> is the cache size in bytes. The specification must be a multiple of 2048. You can use the suffixes K for kilobytes, M for megabytes, or G for gigabytes. Specify 0 to not cache any media content. By default, the cache size is 534288 bytes (0.5 MB).

Loading the hmcdrv module creates a device node at /dev/hmcdrv.

Example

The following specifications are equivalent:
hmcdrv.cachesize=153600
hmcdrv.cachesize=150K