Configuring the NFSv4 Server

You can configure NFSv4 server by setting the values for the parameters in the /opt/mapr/conf/nfs4server.conf file. The configuration parameters are defined within blocks in the file. The following sections describe the blocks and required parameters (within each block) for the Data Fabric NFSv4 server.

By default, the NFSv4 server is configured to rely on a Kerberos infrastructure. If you don't want or don't have a Kerberos infrastructure, comment out the SecType parameter of the EXPORT section.

NFS_CORE_PARAM

Contains the general settings for the daemon. The parameters in this block should not be modified.

Clustered	The value is false. Do not modify this parameter.
Plugins_Dir	The directory for the FSAL libraries. The value is /opt/mapr/lib. Do not modify this parameter.
DRC_TCP_Size	The maximum number of results stored in the DRC. The default value is 16.
DRC_TCP_Recycle_Expire_S	The amount of time after which to expire results stored in DRC. The default value is 60 seconds.
Dirent_Entries_Track	Specifies whether (true) or not (false) to monitor dirent entries. If true, the process restarts if the number of dirent entries exceeds limit.
Num_Log_Files	The maximum number of log files. The default value is 1.
Max_Logfile_Size	The maximum amount of space for each log file. The default value is 1073741824. The total amount of disk space for log files is calculated using the following: Num_Log_Files * Max_LogFile_Size For example, suppose Num_Log_Files = 32 and Max_LogFile_Size = 1GB. Then, the total disk space for log files is 32GB.
Enable_RQUOTA	Specifies whether (true) or not (false) to enable support for remote quotas. The default value is false.
NFS_Protocols	The supported NFS protocols. The only supported value is 4.

NFSV4

Contains settings for the NFSv4 protocol. The following parameters should not be modified.

Delegations	boolean	Specifies whether delegation is supported. The default value is false and should not be modified (cannot be set to true) as delegation is not supported.
Dirent_Cache_Threshold	128	The threshold for caching directory entries. If directory entries exceed threshold, the entries are not cached; caching is enabled only if entries are below this threshold. NOTE This should be used only if readdirplus is true.

EXPORT_DEFAULTS

Contains default values for all subsequent EXPORT blocks. The settings in subsequent EXPORT blocks can override these default values on a per export basis.

Anonymous_Uid	The anonymous UID. The default value is -2, which is converted to a 32 bit unsigned integer (4294967294) when root squash is enabled.
Anonymous_Gid	The anonymous GID. The default value is -2, which is converted to a 32 bit unsigned integer (4294967294) when root squash is enabled.
Protocols	The supported NFS protocols. The default value is 4. This cannot be changed.

EXPORT

Contains settings for exporting a file system.

SecType	The comma-separated list of supported authentication flavors for the export or the type of security. Value can be comma-separated list of: krb5 — authentication krb5i — integrity krb5p — privacy NOTE This must be specified if you want the clients to use kerberos ticket for secure access.
Path	(Required) The (cluster) path to export via NFS. The path should have a leading slash. If just /mapr is specified as the path, all the clusters (listed in the mapr-clusters.conf file) will be visible. To export only a specific cluster, specify the complete path to the cluster to export. NOTE Exporting will not be successful if extra forward slash (/) characters are in the path. For example, the following path will not be exported because of the extra slash (shown in bold) in the path: /mapr/Test3//ATS-VOLUME
Pseudo	(Required for NFSv4 protocol for every directory or volume to export) The pseudo path, which when specified, masks the mount path from the NFS client, for the NFSv4 exports. MapR’s NFSv4 server provides a pseudo-file system where only the exported volumes are visible. This is especially useful in scenarios where one or more volumes in the hierarchy should be hidden and not be visible. When mounting with NFSv4, use the pseudo path. Value can be the volume or directory path.
Export_Id	(Required) The tag used to set the ID for the export or the unique ID to associate with each export. Value should not be 0. NOTE The export ID associated with each export must be the same across all NFSv4 servers on the cluster.
Clients	The list of clients these export permissions apply to. Clients may be specified by hostname, IP address, netgroup, CIDR network address, host name wild card, or simply "*" to apply to all clients.
Squash	Specifies whether to enable or disable root squashing. By default, root squashing is disabled. If root squash is enabled, the values substituted for the root user will be anonymous user (Anonymous_Uid and Anonymouos_Gid); that is, the UID and GID of a file created will not be nfsnobody because the default value of -2 is converted to a 32 bit unsigned integer (4294967294) instead of the 16 bit equivalent (65534), which is the value of nfsnobody.
Access_Type	(Required) The type of access on the mount point. Valid values include: RO — for read-only mount point RW — for read/write mount point MDONLY — for read/write access to metadata only MDONLY_RO — for read-only access to metadata only
FSAL	(Required) The file system to use. Value must be MAPR to use the file system libfsalmapr.so library, which contains the shared library (libMapRClient) and the callbacks.
Attr_Expiration_Time	The timeout value in seconds for file/directory (regular) attributes cache. This value is used to determine whether to use the cached attribute information (only if within the specified timeout window) or to fetch attribute information again. The default is 3.0 seconds, which specifies that cached attribute information must be considered stale and refreshed after 3.0 seconds. A value of 0 disables caching. For better performance, avoid disabling caching.

LOG

Contains configuration for logging. The default log level is INFO. Value can be one of the following:

• FATAL
• MAJ
• CRIT
• WARN
• EVENT
• INFO
• DEBUG
• MID_DEBUG
• FULL_DEBUG

MAPRFS

Contains configurations for NFS gateway access to the Data Fabric file system.

Parameter	Default Value	Description
log_path	/opt/mapr/logs/nfs4	Path for the log files.
ra_sessions	5	Number of parallel read ahead sessions per client library (libMapRClient.so). Each open file acts as one read ahead session. For example, if value is set to 5, up to 5 files can have read ahead sessions per client library (libMapRClient.so). To disable read ahead sessions, set value to 0. NOTE The number of client libraries is 3 by default and cannot be configured.
flush_inline	true	Specifies whether or not to flush all writes inline. Value can be: true — flush all writes inline false — disable inline flushing If enabled (default), writes are sent to server directly. If disabled, for all open files, the buffer is flushed automatically every 3 seconds or when it reaches 64KB.
fast_local_directio	false	Specifies whether to optimize or disable NFS client for local direct IO. Value can be: true — optimize false — disable
nfs_track_memory	false	Specifies whether to enable (true) or disable (false) memory tracking for NFS.
hb_interval	5	The interval (in seconds) for sending heartbeat to CLDB to allow CLDB to determine whether server is running. The CLDB will declare the NFS gateway dead when it loses about 8 heartbeats in a row and will trigger a failover.
req_threshold	5	The amount of time (in seconds) for processing requests. If the threshold is exceeded, warnings will be logged.
client_lib_path	/tmp/nfs4	The location for the client library (libMapRClient). NOTE To install and use NFSv4 and FUSE-based POSIX client on the same node, ensure that the path for the client library for the NFSv4 and FUSE-based POSIX client is not /tmp. Specify a different location for the client libraries. For example, /tmp/nfs4lib.
readdirplus	true	Specifies whether (true) or not (false) to enable extended read from the directory. If enabled (true), each entry returns the name, the file ID, attributes (including the field), and file handle.