Mount filesystems

Discover the two modes for mounting a filesystem on a cluster server: persistent mount mode (stateful) and stateless mount mode. You can also use fstab or autofs for mounting.

Overview

There are two modes available for mounting a filesystem in a cluster server:

  • Persistent mount mode (stateful): This mode involves configuring a client to join the cluster before running the mount command.

  • Stateless mount mode: This mode simplifies and improves client management by eliminating the need for the Adding Clients process.

If you need to mount filesystems from multiple clusters on a single client, refer to the relevant topic for detailed instructions.

In addition, you can mount a filesystem using fstab or autofs.

Related topics

Mount a filesystem using the persistent mount mode

Mount a filesystem using the stateless mount mode

Mount a filesystem using fstab

Mount a filesystem using autofs

Mount filesystems from multiple clusters on a single client

Mount a filesystem using the persistent mount mode

To mount a WEKA filesystem persistently, follow these steps:

  1. Install the WEKA client: Ensure the WEKA client is installed, configured, and connected to your WEKA cluster. See Add clients to an on-premises WEKA cluster.

  2. Identify the filesystem: Determine the name of the filesystem you want to mount. For this example, we use a filesystem named demo.

  3. Create a mount point: SSH into one of your cluster servers and create a directory to serve as the mount point for the filesystem:

    mkdir -p /mnt/weka/demo

  4. Mount the filesystem: As the root user, run the following command to mount the filesystem:

    mount -t wekafs demo /mnt/weka/demo

General command structure: The general syntax for mounting a WEKA filesystem is:

mount -t wekafs [-o option[,option]...] <fs-name> <mount-point>

Replace <fs-name> with the name of your filesystem and <mount-point> with the directory you created for mounting.

Read and write cache modes: When mounting a filesystem, you can choose between two cache modes: read cache and write cache. Each mode offers distinct advantages depending on your use case. For detailed descriptions of these modes, refer to the following links:

Mount a filesystem using the stateless mount mode

The stateless mount mode simplifies client management by deferring the joining of the cluster until the mount operation is performed. This approach is particularly beneficial in environments like AWS, where clients frequently join and leave the cluster.

Key benefits

  • Simplified client management: Eliminates the need for tedious client management procedures.

  • Unified security: Consolidates all security aspects within the mount command, removing the need to manage separate credentials for cluster join and mount.

Prerequisites

Mount a filesystem

Once the WEKA agent is installed, you can create and configure mounts using the mount command. To mount a filesystem:

  • Create and configure mounts: Use the mount command to create and configure the mounts. See Mount command options.

  • Unmounting: Remove existing mounts from the cluster using the unmount command.

Authentication

To restrict mounting to only WEKA authenticated users, set the --auth-required flag to yes for the filesystem. For more information, refer to Mount authentication for organization filesystems.

Set a stateless client with restricted operations on an Isolated port

To restrict a stateless client's operations to only the essential APIs for mounting and unmounting, connect to WEKA clusters through TCP base port + 3 (for example, 14003). This configuration enables operational segregation between client and backend control plane requests.

Mount with restricted options

When mounting with the restricted option, the logged-in user's privileges are set to regular user privileges, regardless of the user's role.

Install the WEKA agent

To install a WEKA agent on a client, run one of the following commands as root on the client:

  • For a non-restricted client:

curl -k https://hostname:14000/dist/v1/install | sh

  • For a restricted client:

curl -k https://hostname:14003/dist/v1/install | sh

The -k flag instructs the curl command to bypass SSL certificate verification.

After running the appropriate command, the agent is installed on the client.

Run the mount command

Command: mount -t wekafs

Command syntax

Use one of the following command lines to invoke the mount command. The delimiter between the server and filesystem can be either :/ or /:

mount -t wekafs -o <options> <backend0>[,<backend1>,...,<backendN>]/<fs> <mount-point>

mount -t wekafs -o <options> <backend0>[,<backend1>,...,<backendN>]:/<fs> <mount-point>

Example: Mount for a restricted stateless client on an isolated port

mount -t wekafs -o restricted -o <options> <backend0>[,<backend1>,...,<backendN>]/<fs> <mount-point>

This setup ensures that the stateless client operates with restricted privileges, maintaining a secure and controlled environment for mounting and unmounting operations on an isolated port.

Parameters

Name
Value

options

See Additional Mount Options below.

backend

IP/hostname of a backend container. Mandatory.

fs

Filesystem name. Mandatory.

mount-point

Path to mount on the local server. Mandatory.

Mount command options

Each mount option can be passed by an individual -o flag to mount.

For all clients types

Option
Description
Default
Remount Supported

readcache

Set the mount mode to read from the cache. This action automatically turns off the writecache.

Note: The SMB share mount mode is always readcache. Set this option to Yes.

No

Yes

writecache

Set the mount mode to write to the cache.

Yes

Yes

forcedirect

Set the mount mode to directly read from and write to storage, avoiding the cache. This action automatically turns off both the writecache and readcache.

No

Yes

dentry_max_age_positive

The time in milliseconds after which the system refreshes the metadata cached entry. This refresh informs the WEKA client about metadata changes performed by other clients.

1000

Yes

dentry_max_age_negative

Each time a file or directory lookup fails, the local entry cache creates an entry specifying that the file or directory does not exist. This entry is refreshed after the specified time (number in milliseconds), allowing the WEKA client to use files or directories created by other clients.

0

Yes

ro

Mount filesystem as read-only.

No

Yes

rw

Mount filesystem as read-write.

Yes

Yes

inode_bits

The inode size in bits may be required for 32-bit applications. Possible values: 32, 64, or auto

Auto

No

verbose

Write debug logs to the console.

No

Yes

quiet

Don't show any logs to console.

No

Yes

acl

Can be defined per mount.

Setting POSIX ACLs can change the effective group permissions (via the mask permissions). When ACLs are defined but the mount has no ACL, the effective group permissions are granted.

No

No

obs_direct

No

Yes

noatime

Do not update inode access times.

No

Yes

strictatime

Always update inode access times.

No

Yes

relatime

Update inode access times only on modification or change, or if inode has been accessed and relatime_threshold has passed.

Yes

Yes

relatime_threshold

The time (number in seconds) to wait since an inode has been accessed (not modified) before updating the access time.

0 means never update the access time on access only.

This option is relevant only if the relatime is on.

0 (infinite)

Yes

nosuid

Do not take suid/sgid bits into effect.

No

Yes

nodev

Do not interpret character or block special devices.

No

Yes

noexec

Do not allow direct execution of any binaries.

No

Yes

file_create_mask

File creation mask. A numeric (octal) notation of POSIX permissions. Newly created file permissions are masked with the creation mask. For example, if a user creates a file with permissions=777 but the file_create_mask is 770, the file is created with 770 permissions.

First, the umask is taken into account, followed by the file_create_mask and then the force_file_mode.

0777

Yes

directory_create_mask

Directory creation mask. A numeric (octal) notation of POSIX permissions. Newly created directory permissions are masked with the creation mask. For example, if a user creates a directory with permissions=777 but the directory_create_mask is 770, the directory will be created with 770 permissions.

First, the umask is taken into account, followed by the directory_create_mask and then the force_directory_mode.

0777

Yes

force_file_mode

Force file mode. A numeric (octal) notation of POSIX permissions. Newly created file permissions are logically OR'ed with the mode. For example, if a user creates a file with permissions 770 but the force_file_mode is 775, the resulting file is created with mode 775.

First, the umask is taken into account, followed by the file_create_mask and then the force_file_mode.

0

Yes

force_directory_mode

Force directory mode. A numeric (octal) notation of POSIX permissions. Newly created directory permissions are logically OR'ed with the mode. For example, if a user creates a directory with permissions 770 but the force_directory_mode is 775, the resulting directory will be created with mode 775.

First, the umask is taken into account, followed by the directory_create_mask and then the force_directory_mode.

0

Yes

sync_on_close

This option ensures that all data for a file is written to the server when the file is closed. This means that changes made to the file by the client are immediately written to the server's disk upon close, which can provide greater data consistency and reliability. It simulates the open-to-close semantics of NFS when working with writecache mount mode and directory quotas. Enabling this option is essential when applications expect returned write errors at syscall close if the quota is exceeded.

No

Yes

nosync_on_close

This option disables the sync_on_close behavior of file writes. When nosync_on_close is enabled, the client does not wait for the server to confirm that all file data has been written to disk before closing the file. This means that any changes made to the file by the client may not be immediately written to the server's disk when the file is closed. Instead, the changes are buffered in memory and written to disk asynchronously later.

No

Yes

Remount of general options

You can remount using the mount options marked as Remount Supported in the above table (mount -o remount).

When a mount option has been explicitly changed, you must set it again in the remount operation to ensure it retains its value. For example, if you mount with ro, a remount without it changes the mount option to the default rw. If you mount with rw, it is not required to re-specify the mount option because this is the default.

Additional mount options using the stateless clients feature

Option
Description
Default
Remount Supported

memory_mb=<memory_mb>

The memory size in MiB the client can use for hugepages.

1400

Yes

num_cores=<frontend-cores>

Specifies the number of processing cores allocated to handle client network operations.

Valid values:

  • 1 to N (where N is the maximum available cores)

  • 0 (only valid with UDP networking mode)

Notes:

  • Cannot be used with core parameter

  • When using NICs with Virtual Functions, num_cores must match the number of configured network devices (net=)

  • Higher core counts may improve performance for multi-connection workloads

Example: core_num=4 # Allocates 4 cores for client processing

1

No

core=<core-id>

Specifies which CPU cores to assign to the WekaFS client.

Multiple cores can be specified as a comma-separated list.

Core 0 is reserved for system use and cannot be specified.

Examples:

-o core=1   # Single core

-o core=1 -o core=3 -o core=5    # Multiple cores

Restrictions:

  • Core IDs must be unique and available on system

  • Cannot be used with num_cores parameter

  • Core 0 not allowed

No

net=<netdev>[/<ip>/<bits>[/<gateway>]]

Specifies network devices for WekaFS client connections. Required for on-premises installations.

Format:

  • Single device: -o net=eth1

  • Multiple devices: -o net=eth1 -o net=eth2 -o net=eth3

Important:

  • For NICs with Virtual Functions (VFs), the number of network devices must equal num_cores

  • Supports both physical NICs and virtual functions

  • Must specify at least one network device

No

remove_after_secs=<secs>

The time in seconds without connectivity, after which the client is removed from the cluster. Minimum value: 60 seconds. 3600 seconds = 1 hour.

3600

Yes

traces_capacity_mb=<size-in-mb>

Traces capacity limit in MB.

Minimum value: 512 MB.

No

reserve_1g_hugepages=<true or false>

Controls the page allocation algorithm to reserve hugepages. Possible values: true: reserves 1 GB false: reserves 2 MB

true

Yes

readahead_kb=<readahead>

The readahead size in KB per mount. A higher readahead is better for sequential reads of large files.

32768

Yes

auth_token_path

The path to the mount authentication token (per mount).

~/.weka/auth-token.json

No

dedicated_mode

full

No

qos_preferred_throughput_mbps

Preferred requests rate for QoS in megabytes per second.

0 (unlimited)

Yes

qos_max_throughput_mbps

0 (unlimited)

Yes

qos_max_ops

Maximum number of IO operations a client can perform per second. Set a limit to a client or clients to prevent starvation from the rest of the clients. (Do not set this option for mounting from a backend.)

0 (unlimited)

Yes

connect_timeout_secs

The timeout, in seconds, for establishing a connection to a single server.


10

Yes

response_timeout_secs

The timeout, in seconds, waiting for the response from a single server.

60

Yes

join_timeout_secs

The timeout, in seconds, for the client container to join the Weka cluster.

360

Yes

dpdk_base_memory_mb

The base memory in MB to allocate for DPDK. Set this option when mounting to a WEKA cluster on GCP. Example: -o dpdk_base_memory_mb=16

0

Yes

weka_version

The WEKA client version to run.

The cluster version

No

restricted

Restricts a stateless client’s operations to only the essential APIs for mounting and unmounting operations.

No

The additional mount options parameters above are only effective on the first mount command for each client, unless stated otherwise.

By default, the command selects the optimal core allocation for WEKA. If necessary, multiple core parameters can be used to allocate specific cores to the WekaFS client. For example, mount -t wekafs -o core=2 -o core=4 -o net=ib0 backend-server-0/my_fs /mnt/weka

Example: On-Premise Installations

mount -t wekafs -o num_cores=1 -o net=ib0 backend-server-0/my_fs /mnt/weka

Running this command on a server installed with the Weka agent downloads the appropriate WEKA version from the backend-server-0and creates a WEKA container that allocates a single core and a named network interface (ib0). Then it joins the cluster that backend-server-0 is part of and mounts the filesystem my_fs on /mnt/weka.

mount -t wekafs -o num_cores=0 -o net=udp backend-server-0/my_fs /mnt/weka

Running this command uses UDP mode (usually selected when the use of DPDK is not available).

Example: AWS Installations

mount -t wekafs -o num_cores=2 backend1,backend2,backend3/my_fs /mnt/weka

Running this command on an AWS EC2 instance allocates two cores (multiple-frontends), attaches and configures two ENIs on the new client. The client attempts to rejoin the cluster through all three backends specified in the command line.

For stateless clients, the first mount command serves a dual purpose:

  1. It installs the WEKA client software.

  2. It joins the WEKA cluster.

Subsequent mount commands can be simplified, requiring only the persistent or per-mount parameters as defined in the Mount command options. The full cluster configuration is not needed for these additional mounts.

WEKA filesystems can be accessed directly through the mount point. You can navigate to the filesystem using standard directory commands, such as cd /mnt/weka/.

When the final WEKA filesystem is unmounted using the umount command, two key actions occur:

  • The client is automatically disconnected from the cluster.

  • The WEKA client software is uninstalled by the agent.

As a result, initiating a new mount operation requires re-specifying the complete cluster configuration, including cluster details, cores, and networking parameters.

When running in AWS, the instance IAM role must provide permissions to several AWS APIs (see the IAM role created in template section).

Memory allocation for a client is predefined. To change the memory allocation, contact the Customer Success Team.

Remount options for stateless clients

Mount options explicitly marked as Remount Supported can be modified using the mount -o remount command. During a remount operation:

  • Unspecified mount options retain their current configuration.

  • To reset a specific option to its default value, use the default modifier.

Example of resetting an option to its default:

  • memory_mb=default restores the default memory configuration.

This approach allows for flexible, granular adjustments to mount parameters without requiring a complete filesystem unmount and remount.

Set mount option default values

Default throughput settings:

  • qos_max_throughput_mbps and qos_preferred_throughput_mbps are initially set with no limit.

Cluster administrator capabilities:

  • Set custom default values aligned with organizational requirements.

  • Reset to initial unlimited configuration.

  • View current default settings.

Key characteristics:

  • Default value modifications only affect new mounts.

  • Existing mount configurations remain unchanged.

Available commands:

  • Set defaults: weka cluster mount-defaults set

  • Reset to initial values: weka cluster mount-defaults reset

  • Display current defaults: weka cluster mount-defaults show

Command syntax:

weka cluster mount-defaults set [--qos-max-throughput qos-max-throughput] [--qos-preferred-throughput qos-preferred-throughput]

Parameters

Option
Description

qos_max_throughput

Specifies maximum requests rate for Quality of Service (QoS) in megabytes per second

qos_preferred_throughput

Specifies preferred requests rate for Quality of Service (QoS) in megabytes per second

Advanced network configuration for stateless clients

Stateless clients allow for customizable network configurations to enhance performance and connectivity. The following parameters can be adjusted:

  • Virtual Functions (VFs)

  • IP addresses

  • Gateway configuration (required if the client is on a different subnet)

  • Physical network devices (for improved performance and high availability)

  • UDP mode

To configure networking, use the -o net=<netdev> mount option with the appropriate modifiers.

Identify <netdev>

<netdev> can be specified using:

  • Network interface name

  • MAC address

  • PCI address of the physical network device

  • Bonded device for redundancy and load balancing

Networking technology compatibility

When using WEKA mounts (wekafs), ensure that clients and backends use the same network type. Supported options include InfiniBand (IB) or Ethernet.

Key considerations

  • The -o net=<netdev> option provides detailed control over network interfaces.

  • Selecting the appropriate configuration helps optimize performance and connectivity.

  • Consistent networking technology is essential for system reliability.

Configure IP, subnet, gateway, and Virtual Functions (VFs)

For improved performance, multiple frontend processes may be required. When using a Network Interface Card (NIC) other than Mellanox or Intel E810, or when deploying a DPDK client on a virtual machine (VM), Single Root I/O Virtualization (SR-IOV) must be used to expose a Virtual Function (VF) of the physical device to the client. Once exposed, the VF can be configured using the mount command.

Assign VF IP addresses and routing

To assign an IP address to a VF or to enable routing when the client is in a different subnet, use the following format:

net=<netdev>/[ip]/[bits]/[gateway]

  • ip, bits, and gateway are optional parameters.

  • If these parameters are not provided, the WEKA system assigns values based on the environment:

    • Cloud environment: The system automatically deduces the IP address, subnet mask, and gateway.

    • On-premises environment: The system assigns values based on the cluster’s default network configuration.

      • If the default network is not set, the WEKA cluster may fail to allocate an IP address for the client.

Example: Configuring VFs on a single physical network device

The following command configures VFs for a specified network device and assigns each VF to a frontend process.

  • The first frontend process is assigned 192.168.1.100.

  • The second frontend process is assigned 192.168.1.101.

  • Both IPs are configured with a 24-bit subnet mask and a default gateway of 192.168.1.254.

mount -t wekafs -o num_cores=2 -o net=intel0/192.168.1.100+192.168.1.101/24/192.168.1.254 backend1/my_fs /mnt/weka

Set maximum VFs on stateless mounts for Intel E810 and Broadcom P2100/2200 NICs

For Intel E810 and Broadcom P2100/2200 NICs, WEKA requires one VF per dedicated core. By default, the system creates 32 VFs. If your WEKA system uses fewer dedicated cores, specify the desired maximum number of VFs using the -o net mount option. For example, if the system uses 8 dedicated cores, add the following to the mount command: -o net=bcm0/vfs@8.

Multiple physical network devices for performance and high availability

For performance or high availability, it is possible to use more than one physical network device.

Multiple physical network devices for better performance

It's easy to saturate the bandwidth of a single network interface when using WekaFS. For higher throughput, it is possible to leverage multiple network interface cards (NICs). The -o net notation shown in the examples above can be used to pass the names of specific NICs to the WekaFS server driver.

For example, the following command will allocate two cores and two physical network devices for increased throughput:

mount -t wekafs -o num_cores=2 -o net=mlnx0 -o net=mlnx1 backend1/my_fs /mnt/weka

Multiple physical network devices for high availability configuration

Multiple NICs can also be configured to achieve redundancy and higher throughput for a complete, highly available solution. For that, use more than one physical device as previously described, and also, specify the client management IPs using -o mgmt_ip=<ip>+<ip2> command-line option.

For example, the following command uses two network devices for high availability and allocate both devices to four Frontend processes on the client. The modifier ha is used here, which stands for using the device on all processes.

mount -t wekafs -o num_cores=4 -o net:ha=mlnx0,net:ha=mlnx1 backend1/my_fs -o mgmt_ip=10.0.0.1+10.0.0.2 /mnt/weka

Advanced mounting options for multiple physical network devices

With multiple Frontend processes (as expressed by -o num_cores), it is possible to control what processes use what NICs. This can be accomplished through the use of special command line modifiers called slots. In WekaFS, slot is synonymous with a process number. Typically, the first WekaFS Frontend process will occupy slot 1, then the second - slot 2 and so on.

Examples of slot notation include s1, s2, s2+1, s1-2, slots1+3, slot1, slots1-4 , where - specifies a range of devices, while + specifies a list. For example, s1-4 implies slots 1, 2, 3, and 4, while s1+4 specifies slots 1 and 4.

For example, in the following command, mlnx0 is bound to the second Frontend process whilemlnx1 to the first one for improved performance.

mount -t wekafs -o num_cores=2 -o net:s2=mlnx0,net:s1=mlnx1 backend1/my_fs /mnt/weka

For example, in the following mounting command, two cores (two Frontend processes) and two physical network devices (mlnx0, mlnx1) are allocated. By explicitly specifying s2+1, s1-2 modifiers for network devices, both devices will be used by both Frontend processes. Notation s2+1 stands for the first and second processes, while s1-2 stands for the range of 1 to 2, and are effectively the same.

mount -t wekafs -o num_cores=2 -o net:s2+1=mlnx0,net:s1-2=mlnx1 backend1/my_fs -o mgmt_ip=10.0.0.1+10.0.0.2 /mnt/weka

Related topic

UDP mode

If DPDK cannot be used, you can use the WEKA filesystem UDP networking mode through the kernel. Use net=udp in the mount command to set the UDP networking mode, for example:

mount -t wekafs -o net=udp backend-server-0/my_fs /mnt/weka

A client in UDP mode cannot be configured in high availability mode (ha). However, the client can still work with a highly available cluster.

Providing multiple IPs in the <mgmt-ip> in UDP mode uses their network interfaces for more bandwidth, which can be useful in RDMA environments rather than using only one NIC.

Related topic

Mount a filesystem using fstab

Using the fstab (filesystem table) enables automatic remount after a reboot. This applies to stateless clients running on an OS that supports systemd, such as RHEL/CentOS 7.2 and up, Ubuntu 16.04 and up, and Amazon Linux 2 LTS.

Before you begin

  • If the mount point you want to set in the fstab is already mounted, unmount it before setting the fstab file.

Procedure

  1. Create a mount point: Run the following command to create a mount point:

mkdir -p /mnt/weka/my_fs

  1. Edit the /etc/fstab file: Add the entry for the WEKA filesystem.

fstab structure

<backend servers/my_fs> <mount point> <filesystem type> <mount options> <systemd mount options> 0 0

Example

backend-0,backend-1,backend-3/my_fs /mnt/weka/my_fs wekafs num_cores=1,net=eth1,x-systemd.requires=weka-agent.service,x-systemd.mount-timeout=infinity,_netdev 0 0

fstab configuration parameters

Parameter
Description

Backend servers/my_fs

Comma-separated list of backend servers with the filesystem name.

Mount point

If mounting multiple clusters, specify a unique name.

For two client containers, set container_name=client1 and container_name=client2.

Filesystem type

Must be wekafs.

Systemd mount options

  • x-systemd.after=weka-agent.service

  • x-systemd.mount-timeout=infinity

  • _netdev

Adjust the mount-timeout to your preference, for example, 180 seconds.

Mount options

  1. Mount the filesystem: Test the fstab setting by running:

mount /mnt/weka/my_fs

  1. Reboot the server: Reboot the server to test the fstab implementation. The filesystem is automatically mounted after the reboot.

Mount a filesystem using autofs

Autofs allows filesystems to be mounted dynamically when accessed and unmounted after a period of inactivity. This approach reduces system overhead and ensures efficient resource utilization. Follow these steps to configure autofs for mounting Weka filesystems.

Procedure

  1. Install autofs on the server: Install the autofs package based on your operating system:

    • For Red Hat or CentOS:

      yum install -y autofs

    • For Debian or Ubuntu:

      apt-get install -y autofs

  2. Configure autofs for WEKA filesystems: Set up the autofs configuration files according to the client type:

    • Stateless client: Run the following commands, replacing <backend-1>, <backend-2>, and <netdevice> with appropriate values:

      echo "/mnt/weka /etc/auto.wekafs -fstype=wekafs,num_cores=1,net=<netdevice>" > /etc/auto.master.d/wekafs.autofs
echo "* <backend-1>,<backend-2>/&" > /etc/auto.wekafs

    • Persistent client: Run the following commands:

      echo "/mnt/weka /etc/auto.wekafs -fstype=wekafs" > /etc/auto.master.d/wekafs.autofs
echo "* &" > /etc/auto.wekafs

  3. Restart the autofs service: Apply the changes by restarting the autofs service:

    service autofs restart

  4. Ensure autofs starts automatically on reboot: Verify that autofs is configured to start on reboot:

    systemctl is-enabled autofs

    • If the output is enabled, no further action is required.

    For Amazon Linux: Use chkconfig to confirm autofs is enabled for the current runlevel:

    chkconfig | grep autofs

    Ensure the output indicates on for the active runlevel. Example output:

    autofs 0:off 1:off 2:off 3:on 4:on 5:on 6:off

  5. Access the WEKA filesystem: Navigate to the mount point to access the WEKA filesystem. Replace <fs-name> with the desired filesystem name:

    cd /mnt/weka/<fs-name>

  • Adjust backend and network device configurations as needed for your deployment.

  • Review distribution-specific documentation for additional configuration options.

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