About Omneon MediaGrid - Harmonic Inc

To configure the amount of memory used for the cache memory limit:
System Configuration
IMPORTANT: The default value for this parameter is sufficient in most cases. If you are unsure of whether
you should change it, please contact Omneon Technical Support for assistance.
1. Type the following command:
sudo sysctl -w debug.omfs_cacheMaxMem = NNN
The memory used, shown as “NNN” is specified in megabytes.
2. Set the memory to the desired value.
Specifying Buffer Memory for Linux Clients
To configure the amount of memory used for ReadAhead buffering:
1. Type the following command:
mount –t omfs /mediagrid/filesys /mnt
-o username=username,password=password,readahead=2
The memory used is specified in units of slices.
2. Set the memory to the desired value.
The above command reserves 2 slices worth of memory for each file that is opened (2 slices for
ReadAhead buffers). The default ReadAhead value is 3 slices. For files using a slice size of 8MB, the
above command would reserve 16MB; the default value would reserve 24MB of memory per file.
Reducing this value increases the number of simultaneously active files an application can use, but
reduces performance. Increasing it may improve performance for some workflows.
See the latest Omneon MediaGrid Release Notes for Linux FSD for the currently supported range of
readahead values.
To configure the amount of memory used for the cache memory limit:
IMPORTANT: The default value for this parameter is sufficient in most cases. If you are unsure of whether
you should change it, please contact Omneon Technical Support for assistance.
1. Type the following command:
echo NNN > /proc/sys/omfs_cache_max_mem_MB
The memory used, shown as “NNN” is specified in megabytes.
2. Set the memory to the desired value.
Memory Usage by the Linux FSD
The Linux FSD allocates all the buffer memory it will use at module load time. The allocation is done
over a short period of time following startup. This eliminates sudden demands for memory, which
occasionally cause the Linux kernel to panic. The gradual increase in memory usage at startup is
expected and normal.
Omneon, Now Part of Harmonic 133