MOUNT.LUSTRE(8) Lustre Configuration Utilities MOUNT.LUSTRE(8)

# [NAME](#NAME)

mount.lustre, mount.lustre\_tgt - mount helper for Lustre client/target service

# [SYNOPSIS](#SYNOPSIS)

`mount -t lustre` **\[**-o *OPTIONS*] *MGSNAME*:/*FSNAME* *CLIENT\_MOUNTPOINT*

`mount -t lustre_tgt` **\[**-o *OPTIONS*] *BLOCK\_DEVICE* *SERVER\_MOUNTPOINT*

# [DESCRIPTION](#DESCRIPTION)

**mount.lustre** and **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 [**mount**(8)](/man/enterprise-packages/lustre/mount.8) as above when the **lustre** or **lustre\_tgt** filesystem type is used. Lustre clients and targets are stopped by using the [**umount**(8)](/man/enterprise-packages/lustre/umount.8) command.

There are two forms for the device option passed to the *mount* command, depending on whether a client or a target service is started:

[*MGSNAME:/FSNAME\[/SUBDIR\]*](#MGSNAME)

mounts the Lustre client filesystem named *FSNAME* (optionally starting at subdirectory *SUBDIR* within the filesystem, if specified) by contacting the Management Service at *MGSNAME*.

[*CLIENT\_MOUNTPOINT*](#CLIENT_MOUNTPOINT)

is the directory where the client filesystem will be mounted and accessed. A client filesystem will typically be listed in [**fstab**(5)](/man/enterprise-packages/lustre/fstab.5) for automatic mount at boot time, is usable like any local filesystem, and provides a full POSIX-compilant interface.

[*MGSNAME:=MGSNODE\[:MGSNODE\]*](#MGSNAME~2)

The *MGSNAME* may be a colon-separated list of *MGSNODE* servers where the MGS service may run. Multiple *MGSNODE* values can be specified if the MGS service is configured for High Availability and may be running on any one of the nodes.

[*MGSNODE:=MGSNID\[,MGSNID\]*](#MGSNODE)

Each *MGSNODE* may specify a comma-separated list of NIDs, if there are different LNet interfaces for the same *MGSNODE*.

[*MGSNID:=HOST@NETTYPE*\[*NET\_NUMBER*\]](#MGSNID)

Each *MGSNID* contains a hostname that can be resolved via the [**hosts**(5)](/man/enterprise-packages/lustre/hosts.5) name service in [**nsswitch.conf**(5)](/man/enterprise-packages/lustre/nsswitch.conf.5), or a numeric IP, IB, or other address that does not need resolution. The **@NETTYPE** is the LNet network type, such as **@tcp**, **@o2ib** or other supported LND type, **@tcp0** if unspecified. The optional *NET\_NUMBER* is the network number for that *NETTYPE*, or 0 if unspecified.

[*BLOCK\_DEVICE*](#BLOCK_DEVICE)

specifies the physical disk or ZFS dataset uses to start the target service formatted by the [**mkfs.lustre**(8)](/man/enterprise-packages/lustre/mkfs.lustre.8) command. The *BLOCK\_DEVICE* may be specified using **-LLABEL** to find the first block device with that label (e.g. **testfs-MDT0000**), or by UUID using the **-UUUID** option. Care should be taken if there is a device-level backup of the target filesystem, which would have a duplicate label and UUID if it is not changed with [**tune2fs**(8)](/man/enterprise-packages/lustre/tune2fs.8) or similar.

[*SERVER\_MOUNTPOINT*](#SERVER_MOUNTPOINT)

is the directory where the target filesystem will be mounted, but is only useful for [**df**(1)](/man/enterprise-packages/lustre/df.1) to show the current space usage, and [**ioctl**(3)](/man/enterprise-packages/lustre/ioctl.3) for block device operations such as [**resize2fs**(8)](/man/enterprise-packages/lustre/resize2fs.8) or [**fstrim**(8)](/man/enterprise-packages/lustre/fstrim.8). It appears in **/proc/mounts** to show that *BLOCK\_DEVICE* is in use.

After successful mount, Lustre clients may have additional parameters set according to those listed in **/etc/lustre/mount.client.params**, and/or the **/etc/lustre/mount.FSNAME.params** files, with lines in the same style as command-line arguments to [**lctl-set\_param**(8)](/man/enterprise-packages/lustre/lctl-set_param.8), with the form *PARAM*=*VALUE*.

# [OPTIONS](#OPTIONS)

[**mgssec=FLAVOR**](#mgssec=)

Specifies the encryption flavour for the initial network RPC connection to the MGS node.

Non-security flavors are: **null**, **plain**, and **gssnull**, which respectively disable, or have no encryption or integrity features for testing purposes.

Kerberos flavors are: **krb5n**, **krb5a**, **krb5i**, and **krb5p**.

Shared-secret key flavors are: **skn**, **ska**, **ski**, and **skpi**.

See [**lgss\_sk**(8)](/man/enterprise-packages/lustre/lgss_sk.8) for more details. The security flavour for client-to-server connections is specified in the filesystem configuration that the client fetches from the MGS.

[**skpath=FILE|DIRECTORY**](#skpath=)

Path to a file or directory with the keyfile(s) to load for this mount command. Keys are inserted into the KEY\_SPEC\_SESSION\_KEYRING keyring with a description containing "lustre:" and a suffix which depends on whether the context of the mount command is for an MGS, MDT/OST, or client. If no **skpath** is specified for client mounts, the mount command will automatically check for a keyfile named **.lgss** in the mount point directory and load it if present. This option is only available when built with --enable-gss.

[**exclude=OSTLIST**](#exclude=)

Start a client or MDT with a (colon-separated) list of known inactive OSTs.

## [CLIENT OPTIONS](#CLIENT_OPTIONS)

In addition to the standard options listed in [**mount**(8)](/man/enterprise-packages/lustre/mount.8), Lustre understands the following **client-specific** options:

[**flock**](#flock)

Enable full distributed [**flock**(2)](/man/enterprise-packages/lustre/flock.2) support, coherent across all client nodes also using this mount option. This is useful if applications need coherent userspace file locking across multiple client nodes, has no measurable performance impact in modern (2.x) versions of Lustre, is therefore the recommended mode, and is enabled by default in Lustre 2.12.3 and newer.

[**localflock**](#localflock)

Enable local [**flock**(2)](/man/enterprise-packages/lustre/flock.2) support, using only client-local file locking. This is faster than mounting with the **flock** option, and can be used for applications that depend on functioning [**flock**(2)](/man/enterprise-packages/lustre/flock.2) but run only on a single node.

[**noflock**](#noflock)

Disables [**flock**(2)](/man/enterprise-packages/lustre/flock.2) support entirely. Applications calling [**flock**(2)](/man/enterprise-packages/lustre/flock.2) will get an **ENOSYS** error. It is possible to mount clients with different options, and only those mounted with **flock** will be coherent amongst each other.

[**lazystatfs**](#lazystatfs)

Allows [**statfs**(2)](/man/enterprise-packages/lustre/statfs.2) (as used by [**df**(1)](/man/enterprise-packages/lustre/df.1) and [**lfs-df**(1)](/man/enterprise-packages/lustre/lfs-df.1)) to return even if some OST or MDT is unresponsive or has been temporarily or permanently disabled in the configuration. This avoids blocking until all of the targets are available. This is the default since Lustre 2.9.0.

[**nolazystatfs**](#nolazystatfs)

Requires that [**statfs**(2)](/man/enterprise-packages/lustre/statfs.2) block until all OSTs and MDTs are available and have returned space usage.

[**user\_xattr**](#user_xattr)

Enable get/set of extended attributes by regular users. See the [**attr**(5)](/man/enterprise-packages/lustre/attr.5) manual page.

[**nouser\_xattr**](#nouser_xattr)

Disable use of extended attributes by regular users. Root and system processes can still use extended attributes.

[**always\_ping**](#always_ping)

Force a client to keep pinging even if servers have enabled suppress\_pings.

[**verbose**](#verbose)

Enable mount/remount/umount console messages.

[**noverbose**](#noverbose)

Disable mount/remount/umount console messages.

[**user\_fid2path**](#user_fid2path)

Enable FID to path translation by regular users via **lfs fid2path**.

[**nouser\_fid2path**](#nouser_fid2path)

Disable FID to path translation by regular users. Root and process with CAP\_DAC\_READ\_SEARCH can still perform FID to path translation.

[**network=NET**](#network=)

Limit connections from the client to be on the network NID specified by 'net'. ´net´ designates a single network NID, like 'o2ib2' or 'tcp1'. This option can be useful in case of several Lustre client mount points on the same node, with each mount point using a different network. It is also interesting when running Lustre clients from containers, by restricting each container to a specific network.

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.

[**mgsname=MGSNAME**](#mgsname=)

Specify a custom hostname for the MGS that will be displayed in **/proc/mounts** instead of the resolved IP address. The network type (e.g., **@tcp**, **@o2ib**) is automatically extracted from the first MGS NID in the device string and should be included in the hostname. If this option is not specified and the device string contains a hostname (not an IP address), the hostname will be automatically extracted and used to generate the mgsname option. This option is purely cosmetic and does not affect the actual connection to the MGS, which is still determined by the device string. This can be useful for making mount entries more readable in system monitoring tools and if MGSNAME is specified as a hostname with DNS resolution that resolves to multiple NIDs instead of numeric addresses.

[**test\_dummy\_encryption**](#test_dummy_encryption)

Enable test dummy encryption mode.

[**noencrypt**](#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

[**retry=NUM**](#retry=)

Specify the number of times the mount attempt may be retried by the client, with an interval starting at 32 seconds for the first 5 minutes, and doubling for every two retries after that.

## [SERVER OPTIONS](#SERVER_OPTIONS)

In addition to the standard mount options and backing disk type (e.g. ldiskfs) options listed in [**mount**(8)](/man/enterprise-packages/lustre/mount.8), Lustre understands the following **server-specific** options:

[**acl**](#acl)

Enable POSIX Access Control List support for all clients. See the [**acl**(5)](/man/enterprise-packages/lustre/acl.5) manual page.

[**no\_create**](#no_create)

Do not allow objects to be created on an OST, or new directories on an MDT after mounting. This allows a (potentially newly-formatted) MDT or OST to be started without clients starting to use it immediately. To allow the new target to be used for allocation, unmount and mount the target again without this option, or run **'lctl set\_param obdfilter.FSNAME-OSTXXXX.no\_create=0'** or **'lctl set\_param mdt.FSNAME-MDTXXXX.no\_create=0'** on the appropriate server node. **NOTE**: this does not start the OST or MDT read-only, it only disables the creation of new objects there. This means existing objects can be be read, modified, or deleted. If the OST or MDT is new then it will not have any objects on it yet.

[**nosvc**](#nosvc)

Only start the MGC (and MGS, if co-located) for a target service, and not the actual MDS or OSS service.

[**noclient**](#noclient)

Do not allow any client connections other than the local interface to the local MGS. This is helpful for the lctl replace\_nids and clear\_conf commands to prevent unwanted client connections.

[**nomgs**](#nomgs)

Start an MDT with a co-located MGS without starting the MGS service.

[**noscrub**](#noscrub)

Do not trigger OI scrub automatically when an inconsistency is detected. It is still possible to start explicitly using the **lctl lfsck\_start**.

[**skip\_lfsck**](#skip_lfsck)

Do not resume the former paused/crashed LFSCK automatically when mounting.

[**abort\_recov**](#abort_recov)

Abort client recovery and start the target service immediately.

[**md\_stripe\_cache\_size=cache\_size**](#md_stripe_cache_size=)

Sets the MD RAID 'stripe\_cache\_size' parameter to *cache\_size* KiB for server OST or MDT block device with a striped RAID configuration.

[**recovery\_time\_soft=timeout**](#recovery_time_soft=)

Allow *timeout* seconds for clients to reconnect for recovery after a server crash. This timeout will be incrementally extended if it is about to expire and the server is still handling new connections from recoverable clients. The default soft recovery timeout is set to 300 seconds (5 minutes).

[**recovery\_time\_hard=timeout**](#recovery_time_hard=)

The server will be allowed to incrementally extend its timeout up to a hard maximum of 'timeout' seconds. The default hard recovery timeout is set to 900 seconds (15 minutes).

# [COMMAND-LINE OPTIONS](#COMMAND-LINE_OPTIONS)

Some command-line options for **mount.lustre** itself may passed from the [**mount**(8)](/man/enterprise-packages/lustre/mount.8) command-line, but are mostly only available for debugging if the [**mount.lustre**(8)](/man/enterprise-packages/lustre/mount.lustre.8) command is run directly. These are separate from the mountpoint options passed to [**mount**(2)](/man/enterprise-packages/lustre/mount.2) for the mountpoint itself, which are listed in the **OPTIONS** section.

[**-f**, **--fake**](#f)

Fake filesystem mount, setting client-specific parameters and adding it to **/etc/fstab** without actually calling the [**mount**(2)](/man/enterprise-packages/lustre/mount.2) system call. Together with the **-v** option this will show what mount options would be set for the filesystem.

[**--force**](#force)

Force mounting the filesystem even if it appears to already be mounted.

[**-h**, **--help**](#h)

Print usage message and exit.

[**-n**, **--nomtab**](#n)

Do not update the **/etc/fstab** file after the mount has successfully completed.

[**-o**, **--options**](#o)

Specify the list of **OPTIONS** to pass to the kernel for *MOUNTPOINT*. These are normally passed from the **mount** command, but can be specified directly for debugging purposes.

[**-v**, **--verbose**](#v)

Print extra information during mounting. This will be passed on from **mount**.

[**-V**, **--version**](#V)

Print the build version of the **mount.lustre** binary and exit.

# [BUGS](#BUGS)

Not very many mount options can be changed with **-o remount**.

# [EXAMPLES](#EXAMPLES)

Start a client for the Lustre filesystem **testfs** at the mount point **/mnt/myfilesystem**. The Management Service is running on a node reachable via NID **cfs21@tcp0**:

```
client# mount -t lustre cfs21@tcp0:/testfs /mnt/myfilesystem
```

Like above example, but mount subdirectory **dir** as fileset:

```
client# mount -t lustre cfs21@tcp0:/testfs/dir /mnt/myfilesystem
```

Like above example, but the Management Service is running on one of the service nodes **mgs1** and **mgs2**, are two different hosts separated by a colon and served as a failover pair, and have both TCP and IB addresses. Lustre tries the first one, and if that fails, it 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:

```
client# mount -t lustre mgs1@tcp0,mgs1ib@o2ib0:mgs2@tcp0,mgs2ib@o2ib0:/testfs /mnt/fs
```

Start the Lustre metadata target service from **/dev/sda1** on mountpoint **/mnt/test/mdt**:

```
mds# mount -t lustre_tgt /dev/sda1 /mnt/test/mdt
```

Start the **testfs-MDT0000** service (by using the disk label), but aborts the Lustre client recovery process for the case that clients are known to be unavailable:

```
mds# mount -t lustre_tgt -L testfs-MDT0000 -o abort_recov /mnt/test/mdt
```

Mount a client filesystem with a custom MGS name for display purposes. The network type **@o2ib** will be automatically appended to the MGS hostname **cfs-mgs** in **/proc/mounts**:

```
client# mount -t lustre -o mgsname=cfs-mgs@o2ib 10.0.0.2@o2ib,10.0.0.4@o2ib:/testfs /myfs
```

Mount a client filesystem with automatic MGS name generation. The hostname **test-mgs** will be automatically extracted from the device string and **mgsname=test-mgs@tcp** will be appended to the list of mount options for display in **/proc/mounts**:

```
client# mount -t lustre test-mgs@o2ib:/testfs /mnt/myfs
```

# [AVAILABILITY](#AVAILABILITY)

**mount.lustre** and **mount.lustre\_tgt** are part of the [**lustre**(7)](/man/enterprise-packages/lustre/lustre.7) filesystem package. **mount.lustre** was added in release 0.10.0, and **mount.lustre\_tgt** was added in release 2.13.0.

# [SEE ALSO](#SEE_ALSO)

[**lfs**(1)](/man/enterprise-packages/lustre/lfs.1), [**lustre**(7)](/man/enterprise-packages/lustre/lustre.7), [**lctl-set\_param**(8)](/man/enterprise-packages/lustre/lctl-set_param.8), [**mkfs.lustre**(8)](/man/enterprise-packages/lustre/mkfs.lustre.8), [**mount**(8)](/man/enterprise-packages/lustre/mount.8), [**tunefs.lustre**(8)](/man/enterprise-packages/lustre/tunefs.lustre.8)

2025-05-22 Lustre

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Document: mount.lustre(8) from lustre 2.17.59-r1 (Chainguard OS)
Source: https://github.com/lustre/lustre-release