LU-10810 clio: SEEK_HOLE/SEEK_DATA on client side

[fs/lustre-release.git] / lustre / doc / mount.lustre.8

diff --git a/lustre/doc/mount.lustre.8 b/lustre/doc/mount.lustre.8
index e4a68f0..cc1a25a 100644 (file)
--- a/lustre/doc/mount.lustre.8
+++ b/lustre/doc/mount.lustre.8
@@ -5,21 +5,26 @@
 .\"
 .\" This file may be copied under the terms of the GNU Public License v2.
 .\"
-.TH mount.lustre 8 "2008 Mar 15" Lustre "configuration utilities"
+.TH mount.lustre 8 "2019 Jul 30" Lustre "configuration utilities"
 .SH NAME
-mount.lustre \- start a Lustre client or target service
+mount.lustre \- mount helper for Lustre client
+mount.lustre_tgt \- mount helper for Lustre target service
 .SH SYNOPSIS
 .br
-.BI "mount \-t lustre [\-o " options "] " "<block_device> <server_mountpoint>"
+.BI "mount -t lustre [-o " options "] " "<mgsname>:/<fsname> <client_mountpoint>"
 .br
-.BI "mount \-t lustre [\-o " options "] " "<mgsname>:/<fsname> <client_mountpoint>"
+.BI "mount -t lustre_tgt [-o " options "] " "<block_device> <server_mountpoint>"
 .SH DESCRIPTION
 .B mount.lustre
-is used to start a Lustre client or target service.  This program should not
-be called directly; rather it is a helper program invoked through
+and
+.B mount.lustre_tgt
+are used to start a Lustre client or target service, respectively.  They
+should not be called directly; rather they are helper programs invoked through
 .BR mount (8)
 as above when the
 .B lustre
+or
+.B lustre_tgt
 filesystem type is used.  Lustre clients and targets are stopped by using the
 .BR umount (8)
 command.
@@ -30,7 +35,7 @@ There are two forms for the device option passed to the
 command, depending on whether a client or a target service is started:
 .TP
 .IR <mgsname> :/ <fsname>[/<subdir>]
-mounts the Lustre filesystem named
+mounts the Lustre client filesystem named
 .I fsname
 (optionally starting at subdirectory
 .I subdir
@@ -46,11 +51,10 @@ for automatic mount at boot time, is usable like any local filesystem, and
 provides a full POSIX-compilant interface.
 .TP
 .I block_device
-starts the target service defined by the
+specifies the phyisical disk or ZFS dataset uses to start the target service
+formatted by the
 .IR mkfs.lustre (8)
-command on the physical disk or ZFS dataset given by
-.IR block_device .
-The
+command.  The
 .I block_device
 may be specified using
 .BI -L label
@@ -66,7 +70,7 @@ or similar.  The mounted target service filesystem at
 .I mountpoint
 is only useful for
 .BR df (1)
-operations and appears in
+operations to show the current space usage, and appears in
 .BR /proc/mounts
 to show the device is in use.
 .SH OPTIONS
@@ -217,6 +221,16 @@ Warning! 'network' option is incompatible with LNet Dynamic Peer Discovery.
 If you want to restrict client NID, please make sure LNet Dynamic Peer Discovery
 is disabled.
 .RE
+.TP
+.BI test_dummy_encryption
+Enable test dummy encryption mode.
+.RE
+.TP
+.BI noencrypt
+Disable Lustre client-side encryption. By default, Lustre client-side encryption
+is enabled, letting users define encryption policies on a per-directory basis.
+fscrypt userspace tool can be used for that purpose, see
+https://github.com/google/fscrypt
 .SH SERVER OPTIONS
 In addition to the standard mount options and backing disk type
 (e.g. ldiskfs) options listed in
@@ -230,6 +244,19 @@ Enable POSIX Access Control List support for all clients.  See the
 .BR acl (5)
 manual page.
 .TP
+.BI no_precreate
+Do not allow objects to be created on the OST after mounting.  This
+allows a (potentially newly-formatted) OST to be started without
+clients starting to use it immediately.  To allow the MDS to create
+objects on the OST mount without this option, or run
+.BI "lctl set_param obdfilter." fsname -OST nnnn .no_precreate=0
+on the OSS to re-enable object creation.
+.BR NOTE :
+this does not start the OST read-only, it only disables the
+creation of new objects on the OST.  This means existing objects
+can be read, modified, or deleted, but if the OST is new then it
+will not have any such objects.
+.TP
 .BI nosvc
 Only start the MGC (and MGS, if co-located) for a target service,
 and not the actual MDS or OSS service.
@@ -297,17 +324,17 @@ tries the second one. On each service node, the comma-separated NIDs refer to
 different interfaces on the same host, and the Lustre client chooses the best
 one for communication based on which network interfaces are available locally.
 .TP
-.B mount -t lustre /dev/sda1 /mnt/test/mdt
+.B mount -t lustre_tgt /dev/sda1 /mnt/test/mdt
 Start the Lustre metadata target service from
 .B /dev/sda1
 on mountpoint
 .BR /mnt/test/mdt .
 .TP
-.B mount -t lustre -L testfs-MDT0000 -o abort_recov /mnt/test/mdt
+.B mount -t lustre_tgt -L testfs-MDT0000 -o abort_recov /mnt/test/mdt
 Start the
 .B testfs-MDT0000
-service (by using the disk label), but aborts the recovery process if
-all of the clients are known to be unavailable.
+service (by using the disk label), but aborts the Lustre client recovery
+process for the case that clients are known to be unavailable.
 .SH BUGS
 Not very many mount options can be changed with
 .BR "-o remount" .