Novell Doc: OES 1 - Understanding How NSS Uses Cache on Linux

27.1 Understanding How NSS Uses Cache on Linux

The following table describes how Novell® Storage Services™ uses the cache on Linux.

OES Release	How NSS Uses the Cache Buffer
OES SP1 Linux	Beginning with OES SP1 Linux, for file data, NSS uses the Linux cache page manger to gain access to all available memory in the system. There are some limits in place so that when copying large files, NSS does not starve other user applications for memory, which is also how it works in NetWare. For metadata, NSS is limited to a percentage of the kernel memory limit, which is 1 GB cache. You can adjust the percentage to be used by NSS with the MinBufferCacheSize parameter. The percentage alloted for OES SP1 can be lower because only metadata is stored in this portion of the cache, not both metadata and file data as it was in the initial release of OES. This method of managing cache buffers is the same method that is used in other Linux file systems such as ReiserFS, Polyserve, XFS, with the exception of EXT.
OES Linux	NSS for OES Linux does not support cache balancing for NSS cache buffers. NSS does not use Linux HighMem. Cache management for NSS cache buffers is limited to a percentage of the cache that is assigned for kernel memory on Linux. The kernel takes a maximum of 1 GB. You can adjust the percentage to be used by NSS with the MinBufferCacheSize parameter.

OES Release

How NSS Uses the Cache Buffer

OES SP1 Linux

Beginning with OES SP1 Linux, for file data, NSS uses the Linux cache page manger to gain access to all available memory in the system. There are some limits in place so that when copying large files, NSS does not starve other user applications for memory, which is also how it works in NetWare. For metadata, NSS is limited to a percentage of the kernel memory limit, which is 1 GB cache.

You can adjust the percentage to be used by NSS with the MinBufferCacheSize parameter. The percentage alloted for OES SP1 can be lower because only metadata is stored in this portion of the cache, not both metadata and file data as it was in the initial release of OES.

This method of managing cache buffers is the same method that is used in other Linux file systems such as ReiserFS, Polyserve, XFS, with the exception of EXT.

OES Linux

NSS for OES Linux does not support cache balancing for NSS cache buffers. NSS does not use Linux HighMem. Cache management for NSS cache buffers is limited to a percentage of the cache that is assigned for kernel memory on Linux. The kernel takes a maximum of 1 GB.

You can adjust the percentage to be used by NSS with the MinBufferCacheSize parameter.