Virtual Server Appliance User manual (Version 3.0.0)  

6 Linux Runtime

The HELIOS Virtual Server Appliance Linux runtime is optimized for the exclusive use of HELIOS software server products. It includes only those Linux components that are required to run the HELIOS services. HELIOS provides full support for the Linux runtime, however non-HELIOS server products or additional Linux packages are not supported by HELIOS.

The Linux runtime is based on an 64 bit system (x86_64). Once Linux is started, a login as root will open HELIOS Configuration Assistant.

6.1 Single-user/recovery mode

When starting the virtual machine, a blue “GNU GRUB” menu appears. Selecting “(recovery mode)” via the cursor and pressing RETURN allows booting into a single-user Linux for maintenance purposes, without any additional services (neither HELIOS nor Linux). Entering the root password opens a shell. The root file system is mounted and the LVM (Logical Volume Manager) is active. Typing exit continues the regular boot process into multi-user mode.

6.2 SSH server

The only activated Linux network service after booting is the SSH server, to allow remote logins.

6.3 NFS services

HELIOS Virtual Server Appliance includes complete Linux NFS server and client services. These use RPC (Remote Procedure Call) services, which are always active by default. The NFS server will automatically be started when NFS shares are configured. The NFS server and client configuration is best done with Configuration Assistant (see 4.4 “Network setup (hostname, IP addresses, DHCP, NFS)”). Consult your Linux manuals for more NFS details.

6.3.1 Features

6.3.2 Enable/disable NFS services

Manually enabling/disabling NFS/RPC services is only needed if customers wish to stop these services for security reasons (stop RPC service daemons from listening on IP ports anymore), or if they have no use for them.


Before these services can be disabled, make sure that neither NFS shares are exported nor NFS mounts are connected. If required, use Configuration Assistant to remove the exported shares and NFS mounts.

Stop related NFS/RPC services

Issue the following commands:

# systemctl stop nfs-kernel-server.service
# systemctl stop nfs-common.service
# systemctl stop rpcbind.service
Disable them from getting started again after a reboot

Issue the following commands:

# systemctl disable nfs-kernel-server.service
# systemctl disable nfs-common.service
# systemctl disable rpcbind.service

In case you installed additional services that also require RPC or NFS services, you must disable these additional services before disabling NFS and RPC services.

You can check dependencies with the apt-cache rdepends command, e.g.:

#  apt-cache rdepends rpcbind
Enable NFS client/server functionality again

If required, NFS services can be re-enabled at a later point in time.


Issue the following commands:

# systemctl enable rpcbind.service
# systemctl enable nfs-common.service
# systemctl enable nfs-kernel-server.service

# systemctl start rpcbind.service
# systemctl start nfs-common.service
# systemctl start nfs-kernel-server.service

6.3.3 NFS usage scenarios

6.3.4 NFS client and server platform specifics

This section contains some information about platform specifics for NFS client or server for the currently supported HELIOS UB64 platforms Solaris (SPARC and x86), AIX, macOS, Linux. See also

  NFS client file NFS server file NFS server command(s)
Solaris 8-9 /etc/vfstab /etc/dfs/dfstab share
Solaris 10-11 /etc/vfstab /etc/dfs/dfstab share, zfs
AIX /etc/filesystems /etc/exports exportfs
macOS /etc/fstab /etc/exports
Linux /etc/fstab /etc/exports exportfs

On other UNIX platforms, use man -k nfs to find out about NFS related commands and files.

6.3.5 VSA Linux man pages related to RPC/​NFS

The following tables include NFS and NFS-related manual pages. Man pages can be accessed via the man command, e.g. man exports.

Man page configuration files Description
exports NFS server export table
idmapd.conf Configuration file for “libnfsidmap”
fstab Static information about the file systems
nfs “fstab” format and options for the NFS file systems
Man page commands/processes Description
exportfs Maintain table of exported NFS file systems
filesystems Linux file system types: btrfs, ext3, ext4, xfs, nfs, ...
rpc.idmapd NFSv4 ID to name mapper
rpc.mountd NFS mount daemon
mount Mount a file system
mount.nfs, mount.nfs4 Mount a Network File System
mountstats Displays NFS client per-mount statistics
nfsd Special file system for controlling Linux NFS server
nfsdcltrack NFSv4 client tracking callout program
nfsidmap The NFS “idmapper” upcall program
nfsiostat Emulate “iostat” for NFS mount points using “/proc/self/mountstats”
nfsstat List NFS statistics
rpcbind Universal addresses to RPC program number mapper
Man page commands/processes Description
rpcdebug Set and clear NFS and RPC kernel debug flags
rpc.gssd RPCSEC_GSS daemon
rpc.idmapd NFSv4 ID to name mapper
rpcinfo Report RPC information
rpc.mountd NFS mount daemon
rpc.nfsd NFS server process
rpc.statd NSM (Network Status Monitor) protocol service daemon
rpc.svcgssd Server-side “rpcsec_gss” daemon
showmount Show mount information for an NFS server
sm-notify Send reboot notifications to NFS peers
umount.nfs, umount.nfs4 Unmount a Network File System

6.4 Included Linux packages

The shell command dpkg -l lists a short description of all included packages, including version numbers.

6.4.1 Install additional Linux packages/​programs

The HELIOS Virtual Server Appliance is a turnkey solution based on the Debian operating system, and the Debian online repositories are enabled for installing updates and additional packages. Additional services and programs can be installed using the Debian “apt” utility.

However, HELIOS Virtual Server Appliance is only supported with the package configuration as released by HELIOS. Additional or updated packages bear the risk that changes may harm overall security and server performance. HELIOS does not support modified configurations nor any additional services or programs.


Do not install any services that may conflict with HELIOS services! That is services that provide AFP or SMB access, DHCP, MDNS or Remote LPR servers, and other services that may use the same TCP ports as the HELIOS services (see the “C.8 TCP ports used by HELIOS” chapter in the HELIOS Base manual).

6.5 Root file system

The HELIOS virtual server Linux runtime uses LVM2 for the root file system and for swapping. The system disk volume group is called “rootvg”. Advantages are a flexible storage management and snapshots. The “rootvg” volume group can be managed via HELIOS Configuration Assistant, in the Manage other volume groups (Advanced storage setup) menu.

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HELIOS Manuals November 19, 2020