Configuring 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 MapR NFSv4 server.

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 NFSv4 protocol. The following parameter 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 filesystem.

`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-filesystem 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.
`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 filesystem to use. Value must be MAPR to use the filesystem `libfsalmapr.so` library, which contains the shared library (`libMapRClient`) and the callbacks.

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 MapR filesystem.

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.

Note:

The libnfsidmap must be configured to use nsswitch, a translation mechanism for mapping names to IDs, in the /etc/idmapd.conf file.
The NFSv3 (mapr-nfsserver) nodes cannot failover to NFSv4 server nodes and vice versa. Ensure that different set of VIPs are assigned for NFSv3 and NFSv4 server nodes. When running the maprcli virtualip add command to set up VIPs, list the MACs of the respective nodes so that the failover works properly (this is necessary if both NFSv3 and NFSv4 are going to be set up for same cluster). The MACs should be mutually exclusive as both NFSv4 and NFSv3 servers cannot run on the same node.