A.5 Cache Management Commands

Use the commands in this section to manage the cache for NSS volumes.

A.5.1 Cache Command

nss /MinBufferCacheSize=value

Sets the specified minimum number of NSS buffer cache entries, where value is the number of 4-KB buffers to assign for NSS.

Default: 30000 for NSS

Range: 10000 for NSS to the amount of memory in KB divided by 4 KB (the block size).

A.5.2 ID Cache Commands

Use the following command at the nsscon prompt in order to synchronize the cache of eDirectory IDs that is maintained for controlling access to NSS volumes.

nss /IDCacheResetInterval=value

Set the number of seconds between invalidation of the ID cache.

Default: 90000

Range: 0 to 200000000

ResetIDCache

Reset the various eDirectory ID caches.

If you Linux-enable a user who has been logged into the system before being Linux-enabled, ensure to execute the resetidcache command from the NSS Console (nsscon) utility. This allows proper reporting of ownership because it resets the mapping of user identities in the ID cache and forces it to update with the Linux UID for the user.

If you LUM disable the user, ensure to execute the resetidcache command from the NSS Console (nsscon) utility. Run this command after 30 minutes, because NCP server clears its cache periodically at the interval of 30 minutes. This allows proper reporting of ownership because it resets the mapping of user identities in the ID cache.

nss /IDCacheSize=value

Sets the maximum number of entries for NSS GUID to ID and ID to GUID cache.

For example, nss /IDCacheSize = 256000

Default: 16384

Range: 16384 to 524288

A.5.3 Cache Monitoring Commands

CacheStats

Shows the caching statistics for buffers.

ResetStats

Resets caching and file statistics.

A.5.4 UnplugAlways Command for the Read Queue

nss /(no)UnplugAlways

When enabled, this option allows NSS to unplug the device queue after queuing each read. This improves performance significantly on certain workloads, such as Linux copy (cp) command.

NOTE:In OES 2 SP1, the UnplugAlways default setting is on (enabled). OES 2 SP2 onwards, the UnplugAlways default setting is off (disabled).

For OES 2 and OES 11 SP2 the UnplugAlways default setting is off (disabled). The OES 2 version of this option is available as patch Novell Storage Services (NSS) and Novell Cluster Services (NCS) 20080806 (oes2-novell-nss-5503) for 32-bit and 64-bit architectures. The patch is available on the Novell Downloads Web site.

Examples

Enable UnplugAlways by entering the following at the nsscon prompt as the root user:

nss /UnplugAlways

Disable UnplugAlways by entering the following at the nsscon prompt as the root user:

nss /NoUnplugAlways