New Attributes Added to NFS and RPC Subsystems

Several new tunable attributes have been added to the the NFS server subsystem, nfs_server, the NFS client subsystem, nfs, and the Remote Procedure Call (RPC) subsystem, rpc Previously, the configurations produced by these attributes could only be changed by using the dbx command. Now, you can easily use and modify these kernel subsystem configurations with the sysconfig command.

The following list provides a brief description of these new attributes. For more information about setting the attributes, see the new sys_attrs_nfs(5) reference page delivered in this kit.

nfs_server:
- nfs_write_gather and nfs3_write_gather
  Improves NFS V2 and V3 performance by gathering several write requests, performing a single sync, and sending all of the replies.
- nfs_ufs_lbolt and nfs3_ufs_lbolt
  Enables or disables a delay when NFS V2 and NFS V3 returns writes. This attribute affects write gathering for all file systems (not just UFS) for NFS V2 and V3.
nfs:
- nfs_cto
  Enables or disables Close-To-Open (CTO) consistency to reduce the number of client caches that provide applications with stale NFS data.
- nfs_quicker_attr
  Enables or disables synchronous cache flush.
- nfs3_broken_lookup
  Controls the frequency of console messages related to an NFS V3 problem on some servers where a file lookup would return erroneous data for the parent directory.
- do_client_readdirplus
  Enables or disables the operating system from issuing the readdirplus procedure.
- nfs3_maxreadahead
  Controls the number of outstanding read-aheads.
- nfs3_readaheads
  Controls the number of read-aheads for NFS V3.
rpc:
- use_fastsend
  Enables or disables the optimization of client and server code used by NFS over UDP.
- use_fastroute
  Enables or disables improved fastsend optimization that affect the NFS server.