Comet Backup installation

Windows

System Requirements

Specification	Minimum	Recommended
CPU	`x86` or `x86-64` processor (minimum 4 cores/threads)	`x86` or `x86-64` processor (8 cores/threads or more)
RAM ¹	`8 GB`	`16 GB`
OS	Windows 7 or newer	Windows 10 or newer
OS (Server)	Windows Server 2008 R2 or newer	Windows Server 2016 or newer
Hard Drive		SSD or NVME Drive
Network ²	`1 Mbps` or faster download/upload speed	`1 Gbps` or faster download/upload speed.

¹ Comet does not consume 8GB of RAM. Memory consumption varies depending on the job being run.

² Links with high latency or unstable WAN connections are not recommended, as these impact both upload and download performance.

Windows XP / Server 2003

At the time of writing, there is no version of Comet available for Windows XP / Server 2003. All versions of Comet rely heavily on features that were only introduced in Windows Vista / Server 2008.

Windows XP / Server 2003 no longer receives security patches from Microsoft. It is unsafe to connect such a machine to the internet. If you are attempting to supply backup services to a customer in this situation, you should arrange to first upgrade their operating system with urgency.

You can work around this issue by

installing Comet Backup on another machine, and then backup the XP machine over the network; or
virtualizing the XP machine, and backing up the VM guest from the VM host. This also allows you to remove internet access from the XP machine.

Windows Vista / Server 2008

Support for Windows Vista was removed in Comet Backup 22.9.1. The final version of Comet Backup that runs on Vista or Windows Server 2008 is Comet 22.8.x or 22.9.0.

The Comet Server has a mandatory minimum TLS version of TLS 1.2. Windows Server 2008 users may require KB4019276 to continue accessing Comet Server; this update is also required for ESU (Extended Security Updates) for Windows Server 2008.

Windows 7 / Server 2008 R2

Comet Backup continues to support Windows 7 and Server 2008 R2 and will install successfully on these operating systems. However, Microsoft ended Extended support for Windows 7, and Server 2008 R2 on January 14th 2020. Future versions of Comet may remove support for such older versions of Windows which are no longer under active security support from Microsoft.

Windows 8 / 8.1 / Server 2012 / Server 2012 R2

Comet Backup continues to support Windows 8, 8.1, Server 2012, and Server 2012 R2 and will install successfully on these operating systems. However, Microsoft ended Extended support for Windows 8, 8.1, Server 2012, and Server 2012 R2 on October 10th 2023. Future versions of Comet may remove support for such older versions of Windows which are no longer under active security support from Microsoft.

Installation

Run the CometBackup_install.exe file and follow the prompts.

Once installed, the client software prompts for account details to log in.

Silent installation (Windows advanced)

Remote registration requires Comet 23.9.0 or later.

With remote registration (lobby mode) you can remotely register/assign the devices to a User profile, right from the Comet Server admin web interface.

Command Prompt install.exe /S /LOBBY
PowerShell Start-Process -Wait .\install.exe -ArgumentList "/S /LOBBY"

If you wish to enable remote registration for previously installed clients, or rejoin the lobby after a client restart, you can run the following backup-tool command:

cd "C:\Program Files\Comet Backup"
backup-tool.exe login join-lobby [server-url]

The device will appear as "Unregistered" on the Devices page of the Comet Server admin web interface. From here you can register it to a User Profile using the Register button on the right.

With username and password Comet allows you to install and configure the software silently, by running the following example via your remote management software. Silent installations must be started by running from the installer directory. Incorrect quotations may result in errors.

Command Prompt install.exe /S /CONFIGURE=user:password
PowerShell Start-Process -Wait .\install.exe -ArgumentList "/S /CONFIGURE=user:password"

If you make a mistake with the username/password prompt, you can run the cd "C:\Program Files\Comet Backup"; echo "USER`nPASSWORD" | .\backup-tool.exe login prompt PowerShell command to re-enter login details. Please take care with the `n character separating the username and password.

With install token (passwordless) Comet also allows you to install the software and register the device silently, by running the following example via your remote management software. Silent installations must be started by running from the installer directory.

Command Prompt install.exe /S /TOKEN=installtoken
PowerShell Start-Process -Wait .\install.exe -ArgumentList "/S /TOKEN=installtoken"

You can generate the installation token by calling API AdminCreateInstallToken and the token is for a single use only. It can be used to hide the username and password from the command-line parameters.

Other optional arguments

Disable shortcuts Comet allows you to disable the software shortcuts for the silent installation, by adding command-line argument /SHORTCUT=disable. For example, if you want to install with token while no shortcuts are created, you can run the following command-line,

Command Prompt install.exe /S /TOKEN=installtoken /SHORTCUT=disable
PowerShell Start-Process -Wait .\install.exe -ArgumentList "/S /TOKEN=installtoken /SHORTCUT=disable"

Disable tray icon Comet allows you to disable the tray icon for the silent installation, by adding command-line argument /TRAYICON=disable.

Log on backup.delegate service as Local System account Comet allows you to explicitly set backup.delegate service to log on as Local System account for the silent installation, by adding command-line argument /ISLOCALSYSTEM=yes

Set target login server Comet allows you to set the target login URL for the Comet Server (Auth Role), by adding command-line argument /SERVER="https://example.com".

Command Prompt install.exe /S /CONFIGURE=user:password /SERVER="https://example.com"
PowerShell Start-Process -Wait .\install.exe -ArgumentList "/S /CONFIGURE=user:password /SERVER=`"https://example.com`"

RMM Deployment Example Scripts

Example scripts to deploy the client software in bulk with remote management software.

Windows/PowerShell

$dlPath = "C:\TEMP"
$serverURL = "https://example.com"

if (-not (Test-Path $dlPath)) {
    mkdir $dlPath
}
Set-Location $dlPath
Invoke-WebRequest -Uri "$($serverURL)/dl/2" -OutFile install.exe
Start-Process -Wait .\install.exe -ArgumentList "/S /LOBBY /SERVER='$($serverURL)/'"
Remove-Item -Path ".\install.exe"

MacOS/Bash

#!/bin/bash
SERVERURL=https://example.com
REBRANDEDNAME="Comet Backup"
INSTALLERNAME=CometBackup.pkg

curl -o /private/tmp/CometBackup.pkg "$SERVERURL/dl/8"
sudo /usr/sbin/installer -allowUntrusted -pkg "/private/tmp/$INSTALLERNAME" -target /
"/Applications/$REBRANDEDNAME.app/Contents/MacOS/backup-tool" login join-lobby "$SERVERURL/"
rm "/private/tmp/$INSTALLERNAME"

Service account

Comet automatically creates a Virtual Account (NT SERVICE\backup.delegate) with all necessary permissions to back up files on the PC.

Isolating Comet Backup under a Virtual Account is supported on Windows 7 or later, and Windows Server 2008 R2 or later when that server is not a Domain Controller. On other machines (e.g. Windows Server 2008 RTM, and domain controllers) the backup service will run as LOCAL SYSTEM by default.

On a Domain Controller running Windows Server 2008 R2 or later, we recommend configuring a Managed Service Account inside Active Directory for the backup service. This allows you to isolate the backup service permissions in a password-less service account. You should apply this to the backup.delegate service (but not the backup.elevator service, used for software updates).

Upgrading

The installer will safely remove and upgrade any prior version of Comet Backup, including those with a different software branding.

If the product name is changed as a result of the installation process, the newly-branded software may be installed into the old-branded directory name. You can avoid this issue by completely uninstalling and reinstalling the software.

Silent upgrade (advanced)

You can silently upgrade the software remotely via the Comet Server interface, or by running install.exe /S via your remote management software.

Service account

If you customize the backup.delegate service to use any other user account, your changes will be preserved in any future software upgrade.

Uninstall

The software can be uninstalled via the "Apps and Features" section in the Windows Control Panel.

During this process, you may be prompted whether you wish to preserve any username/password credentials saved on this computer.

In Comet 21.9.10 and later, you can also remove the saved credentials manually by running the backup-tool.exe login disconnect command.

Silent uninstallation

You can silently uninstall Comet Backup for Windows by passing the /S command-line argument (e.g. "C:\Program Files\Comet Backup\Uninstall.exe" /S).

If you also want to remove the saved username/password credentials, add this command-line "C:\Program Files\Comet Backup\Uninstall.exe" /S /ISDELETECREDENTIAL=yes

macOS

System Requirements

Specification	Minimum	Recommended
CPU	`x86-64` or `Apple Silicon` processor (minimum 4 cores/threads)	`Apple Silicon` processor (8 cores/threads or more)
RAM ¹	`8 GB`	`16 GB`
OS	macOS 10.13 "High Sierra"	macOS 14 "Sonoma"
Hard Drive		SSD or NVME Drive
Network ²	`1 Mbps` or faster download/upload speed	`1 Gbps` or faster download/upload speed.

¹ Comet does not consume 8GB of RAM. Memory consumption varies depending on the job being run.

² Links with high latency or unstable WAN connections are not recommended, as these impact both upload and download performance.

macOS 10.13 "High Sierra" or later is supported on the latest versions of Comet. For older macOS versions the latest supported releases are:

macOS Version	Last Supported Voyager Release	Last Supported Quarterly Release
OS X 10.9 "Mavericks"	Comet 19.12.1	Comet 19.11.x series
OS X 10.10 "Yosemite"	Comet 22.9.0	Comet 22.8.x series
OS X 10.11 "El Capitan"	Comet 23.6.2	Comet 23.5.x series
macOS 10.12 "Sierra"	Comet 23.6.2	Comet 23.5.x series

macOS 10.12.1 is required for Let's Encrypt's ISRG Root X1
macOS 11.0 is required for Apple silicon

Installation

The macOS operating system requires codesigning to be enabled in order to launch a downloaded .pkg file. If you have not configured codesigning for macOS, you will be unable to launch the installer. However, you can bypass this by right-clicking the .pkg file and choosing Open.

Run the Comet Backup.pkg file and follow the prompts.

Once installed, the client software prompts for account details to log in.

If you are running the .pkg file from the Downloads directory, macOS will offer to move the .pkg file to the Trash after a successful installation.

Silent Installation (macOS Advanced)

Remote registration requires Comet 23.9.0 or later.

With remote registration (lobby mode)

By running the following script via your remote management software, you can remotely register/assign the devices to a User Profile, right from the Comet Server admin web interface.

# Silently install the client software -
sudo /usr/sbin/installer -allowUntrusted -pkg "Comet Backup.pkg"  -target /

# Join the remote registration lobby -
# This is not a persistent connection and will NOT auto reconnect after a client restart
"/Applications/Comet Backup.app/Contents/MacOS/backup-tool" login join-lobby "https://<my-comet-server>.com/"

The device will appear as "Unregistered" on the Devices page of the Comet Server admin web interface. From here you can register it to a User Profile using the Register button on the right.

With username and password

By running the following script via your remote management software, you can silently register a macOS deivce to static User Profile.

NOTE: This does require the user (not admin) password to be plaintext on the client. We recommend using remote registration (lobby mode) to avoid this

PKG_NAME="Comet Backup"
COMET_HOST="https://<my-comet-server>.com/"
COMET_USERNAME="test_comet"
COMET_PASSWORD="<password>"

INSTALLER_PATH="$PKG_NAME.pkg"
BACKUP_TOOL_PATH="/Applications/$PKG_NAME.app/Contents/MacOS/backup-tool"

sudo /usr/sbin/installer -allowUntrusted -pkg "$INSTALLER_PATH"  -target /

(
    echo "$COMET_USERNAME";
    echo "$COMET_PASSWORD";
) | OVERRIDE_INSTALL_SERVER="$COMET_HOST" "$BACKUP_TOOL_PATH" login prompt

Silently granting Full Disk Access permission

macOS 10.14 Mojave and later have added a requirement to grant the "Full Disk Access" permission. macOS does not allow programs to set this permission automatically and it cannot be set as part of the silent install with the above instructions.

However, if you are intending to use the silent install feature via an RMM software that acts as the device's MDM (e.g. Jamf / Addigy / Meraki Systems Manager / ...) then you can set a Privacy Preferences Policy Control (PPPC) that remotely enables the "Full Disk Access" option for Comet Backup's application ID. The application ID for Comet Backup can be customized via your Comet Server as part of the macOS client branding settings.

Upgrading

The installer will safely remove and upgrade any prior versions of Comet Backup, including those with a different software branding.

Silent upgrade (advanced)

You can silently upgrade the software remotely via the Comet Server interface, or by running /usr/sbin/installer -allowUntrusted -pkg "Comet Backup.pkg" -target / via your remote management software.

Uninstallation

macOS does not have a standard system for uninstalling programs. However, you can still uninstall Comet by running the following command from a terminal window:

sudo -u root "/Applications/Comet Backup.app/Contents/Resources/uninstall"

This will automatically stop all running Comet processes, unregister Comet's launchd services, and remove all application files from the disk.

Uninstalling the software preserves any username/password credentials saved on this computer. If you also want to remove the saved username/password credentials, add this command-line:

sudo -u root "/Applications/Comet Backup.app/Contents/Resources/uninstall" --also-remove-saved-passwords

In Comet 21.9.10 and later, you can also remove the saved credentials manually prior to uninstallation by running the /Applications/Comet Backup.app/Contents/MacOS/backup-tool login disconnect command.

Linux (Debian, Ubuntu)

This feature requires Comet 23.12.5 or later.

Install Comet Backup using the Debian client package. The Debian package installs the Comet client binaries and a systemd unit script to start and stop the service. The installed service is named backup-tool.

See System Requirements below.

Installation

Install the package using apt install in the directory where the .deb file was downloaded. E.g.:

sudo apt install ./Comet_Backup-23.12.5.deb

The installer will

Install the software into a branded /opt/BRANDNAME/ subdirectory
Prompt you for an initial username and password (if previous configuration was not found)
Prompt you for the URL of the comet server to attach to
Register the current Linux device using the provided Comet user account details
Start running Comet Backup in the background.

Managing the Service

The Comet service is installed with the name backup-tool. It can be managed using the standard systemctl commands. See this Red Hat article for reference.

Silent install (Debian package)

The deb package installer prompts for your login details using Debconf. For a silent install experience, you can pre-seed answers to the install questions by using debconf-set-selections.

Package compatibility

You can install the .deb package over the top of an existing Comet Backup installation that used the "Other distribution" (.run) package. The .deb installer will detect the existing installation and convert the settings appropriately.

If you install the "Other distribution" (.run) package over the top of an existing .deb install, Comet 23.12.5 or later will understand the previous .deb package and perform a safe conversion. Installing an earlier version of the .run package will result in a mixed installation. To avoid this, ensure to safely uninstall the .deb package first.

Uninstall

You can uninstall the package by running apt remove backup-tool.

By default, removing the package will preserve your saved credentials for future reinstall. To forget any saved configuration, run apt purge backup-tool. This command will also uninstall the package if it is still installed.

Linux (Red Hat Enterprise Linux (RHEL), CentOS)

Install Comet Backup using the "Other distribution" package.

Linux NAS (Synology)

Since Comet 21.12.6, branded Synology SPKs can be generated and downloaded from the Comet Server web interface. The web interface offers two downloads for Synology: one for DSM 6 and one for DSM 7. Due to Synology packaging rules, these SPKs are not interchangeable.

SPKs are available for Synology NAS' which meet the following requirements:

CPU: x86_64, i686, ARMv7, or ARMv8
DSM version: 6 or 7

The Synology SPK does not include a graphical client. Instead, creating Protected Items and running backups and restores can be done from your Comet Server.

Installation

DSM 6 only: Installation of packages published by any publisher must be allowed before Comet can be installed. This setting can be enabled from the Package Center; in Settings > General > Trust Level, select the "Any publisher" radio button and accept the settings.

Installation of Comet on a Synology NAS follows the same process as installing any other SPK:

Open the Package Center
- If on DSM 6, ensure the settings noted above have been applied.
Click "Manual Install" in the top right
Upload the .spk file downloaded from Comet Server
- If on DSM 7, accept the prompt to allow the installation of a third-party package.
Accept the license agreement
Enter credentials the appropriate Comet Server and user
- If a previous version of Comet has been installed on the NAS and its settings were not removed when it was uninstalled, the installer will automatically detect the credentials. Leaving all fields blank will reuse the existing credentials; new credentials can also be entered as usual and will take precedence.
Click "Apply" to complete the installation

Permissions

On DSM 7, Comet runs a special package-specific user named backuptool. In order to perform backups and restores, this user must be granted permissions to access the appropriate Shared Folders. This does not apply to DSM 6.

Log in to the Synology NAS
Open the Control Panel and go to Shared Folders
Select the Shared Folder containing the data to be backed up and click Edit
In the Permissions tab, select "System internal user" from the dropdown menu on the left
For the user backuptool, click the checkbox in the Custom column
In the dialog that appears, ensure the following:
1. "Apply to:" is set to "All"
2. All permissions are checked

Limitations

Due to restrictions placed on packages by Synology for DSM 7, Comet runs as a special package-specific user, which results in some limitations:

Remote upgrade/uninstall is not supported. This is because third-party SPKs are no longer allowed to run as root, which means Comet cannot initiate a package upgrade/uninstall from within a package itself. To upgrade, install the new version manually in place of the old version.
When performing a restore to a Synology NAS, permissions/ownership may not be restored correctly. This is because a package user is not allowed to chown to a user other than themselves.

After installation

The Synology SPK does not provide a graphical client for Comet. Creating Protected Items and manually running backups or restores is done from the Comet Server web interface.

Creating a Protected Item can be done from the Protected Items tab on the user's page:

Backups and restores can be run by selecting the connection to the online Synology device from the Devices tab on the user's page:

Video

Here is a video tutorial showing the steps to download the Comet Synology installer, and walks you through installation and how to configure a backup and restore from the Comet Server interface.

Linux (Other NAS)

Install Comet Backup using the "Other distribution" package.

Linux (Other Distribution)

This is a distribution-agnostic package that can be used if Comet does not have a more specific package available for your Linux distribution.

Please note that in order to avoid distribution-specific differences, the package does not automatically start on boot. You should configure your system to run the launch script in /opt/ on boot (e.g. via a systemd unit, upstart script, /etc/init.d/ script, or a line in init.rc).

System Requirements

Specification	Minimum	Recommended
CPU	`x86` with `SSE2`, `x86-64` or `ARM` processor (minimum 4 cores/threads)	`x86-64` or `ARM` processor (8 cores/threads or more)
RAM ¹	`8 GB`	`16 GB`
OS	Kernel 2.6.23 or later	Kernel 5.0 or later
Hard Drive		SSD or NVME Drive
Network ²	`1 Mbps` or faster download/upload speed	`1 Gbps` or faster download/upload speed.

¹ Comet does not consume 8GB of RAM. Memory consumption varies depending on the job being run.

² Links with high latency or unstable WAN connections are not recommended, as these impact both upload and download performance.

Additional Requirements

Support for ISRG root X1 certificates for Let's Encrypt requirements
Unique SSH host keys (This can be an issue with cloned VMs)
Dependencies
- bash, xz, GNU awk, and standard GNU/Linux system utilities
- ca-certificates and tzdata (see below)

ARM CPU support

Comet Backup is available for multiple ARM platform variants. The Comet Backup installer will select the best available binary for your hardware at install-time.

The following platform variants are supported:

Platform	Description
`ARMv8l`	ARM 64-bit (`Aarch64`), no `glibc` required
`ARMv7l`	ARM 32-bit with `vfp`, and a `glibc`-based OS with the "hard-float" ABI (`gnueabihf`)
`ARMv6kl`	ARM 32-bit with `vfp`, no `glibc` required

Timezone database dependency

Comet Backup on Linux requires the OS to provide an up-to-date timezone database, to perform timezone calculations

On many Linux distributions, installing the tzdata or timezone package should be sufficient
Otherwise, Comet will look for a timezone database in all of the following locations;
- /usr/share/zoneinfo
- /usr/share/lib/zoneinfo
- /usr/lib/locale/TZ

CA certificate database dependency

Comet Backup on Linux requires the OS to provide an up-to-date set of root certificate authorities, to validate HTTPS / SSL connections.

On many Linux distributions, installing the ca-certificates package should be sufficient
Otherwise, Comet will look for a certificate bundle in all of the following locations;
- /etc/ssl/certs/ca-certificates.crt (used by Debian/Ubuntu/Gentoo etc.)
- /etc/pki/tls/certs/ca-bundle.crt (used by Fedora/RHEL 6)
- /etc/ssl/ca-bundle.pem (used by OpenSUSE)
- /etc/pki/tls/cacert.pem (used by OpenELEC)
- /etc/pki/ca-trust/extracted/pem/tls-ca-bundle.pem (used by CentOS/RHEL 7)

Installation

Run the .run file. This is a self-extracting archive, and will need to be executed in an elevated environment.

The installer will

install the software into a branded /opt/BRANDNAME/ subdirectory
prompt you for an initial username and password
register the current Linux device into that Comet account
start running Comet Backup in the background.

If you make a mistake with the username/password prompt, you can run the /opt/BRANDNAME/backup-tool login prompt command to re-enter login details.

Prior to Comet 21.9.10, if you make a mistake with the username/password prompt should follow the instructions below to completely remove the software, and then start the installation again.

Linux Installation options

You can control the installer by setting environment variables in your shell before running the .run file.

The following options are available:

WRITE_INSTALL_LOG. Set this to a file path, to record details of the installation.
OVERRIDE_INSTALL_SERVER. Set this to a URL (including http/https and trailing slash) to override the Comet Server URL used by Comet Backup.

You can set an environment variable in bash either on the same line (e.g. WRITE_INSTALL_LOG=install.log ./Comet_Backup-xx.x.x.run) or as a separate export command (e.g. export WRITE_INSTALL_LOG=install.log followed by ./Comet_Backup-xx.x.x.run).

Silent installation (Linux advanced)

Remote registration required Comet 23.9.0 or later.

With remote registration (lobby mode)

By running the following script via your remote management software, you can remotely register/assign the devices to a User Profile, right from the Comet Server admin web interface.

./Comet_Backup-xx.x.x.run --lobby

You can also silently rejoin the lobby, or configure a different Comet Server, using the following command: /opt/BRANDNAME/backup-tool login join-lobby [server-url]

The device will appear as "Unregistered" on the Devices page of the Comet Server admin web interface. From here you can register it to a User Profile using the Register button on the right.

With username and password

Comet allows you to install and configure the software silently. This allows you to remotely push client installations remotely, using your preferred remote management software.

To run the installer silently, run:

export COMET_USERNAME=xxxx
export COMET_PASSWORD=xxxx
(echo $COMET_USERNAME; echo $COMET_PASSWORD;) | ./Comet_Backup-xx.x.x.run

NOTE: COMET_USERNAME and COMET_PASSWORD are for the user profile, not the Comet Server administrator.

You can also silently reconfigure the software using the same pipe syntax: (echo $COMET_USERNAME; echo $COMET_PASSWORD;) | /opt/BRANDNAME/backup-tool login prompt

Restarting at boot

The installer creates a backup-daemon-start.sh script that can start the service. The Comet Backup agent on "Other Distribution" Linux can be restarted by running the backup-daemon-start.sh script.

In order for Comet Backup to start after a system reboot, you must configure this script to be run on system boot. Different Linux distributions support different methods for running commands on system boot: choose the most appropriate method for your Linux distribution. Some common choices are documented below.

Preserve HOME environment variable

Comet uses the $HOME environment variable to find its saved credentials. When configuring Comet to start at system boot, ensure that the $HOME environment variable is set (i.e. to /root/), to ensure that Comet can find its saved credentials. If Comet is unable to log in, it's possible that your Linux distribution does not set $HOME at this early-boot stage. In that case, you should try running HOME=/root/ /opt/CometBackup/backup-daemon-start.sh & instead. Comet will automatically try to use /root/ as the $HOME directory if $HOME is not already set or if it is set to a blank path.

Note: If you execute the .run installation script as root, this may have different results than if you execute the .run script using an elevated terminal session with 'sudo'. The 'sudo' command preserves the $HOME variable on Ubuntu; whilst on Debian the $HOME variable is erased, and sudo then sets it to the home directory of the originating user.

Start in the background

If you are running commands over SSH, please be aware that the backup-daemon-start.sh script runs in the foreground and will die when the SSH session is closed. You can avoid this by running the script in the background.

You can run the script in the background (daemonize) by using the backup-daemon-start-background.sh file instead.

Startup via `rc.local`

You can make Comet Backup start at system boot by adding an entry to the rc.local file.

First, find the rc.local file on your system:

/etc/rc.local (Debian/Ubuntu)
/etc/rc.d/rc.local (CentOS/RHEL)

Add the following content to the rc.local file:

/opt/CometBackup/backup-daemon-start.sh &

If the rc.local file contains an exit 0 statement, the additional command should be added before such a statement.

As of CentOS 7, the rc.local file is not executable by default. You should run chmod +x on the rc.local file to enable using this method for startup scripts.

Startup via `rc.d`

You can make Comet Backup start at system boot by adding a file to the rc.d directory.

First, find the rc.d directory on your system:

/usr/local/etc/rc.d (Synology DSM 6.1+)

Add a new file to the rc.d directory with the following contents:

#!/bin/bash
/opt/CometBackup/backup-daemon-start-background.sh

Mark the file as executable: chmod +x /usr/local/etc/rc.d/my-comet-startup-script.sh

Startup via `cron`

You can make Comet Backup start at system boot by adding an entry to root's crontab.

Run crontab -e -u root to launch a crontab editor
Add the line @reboot /opt/CometBackup/backup-daemon-start-background.sh

Startup via `init.d`

No further documentation is currently available for this topic.

Startup via `systemd`

You can use the following unit as an basic example:

[Unit]
Description=Comet Backup Client
After=network-online.target

[Service]
Type=simple
RemainAfterExit=true
KillMode=process
User=root
ExecStart=/opt/CometBackup/backup-daemon-start.sh

[Install]
WantedBy=multi-user.target

This unit file correctly starts the Comet Backup service at system boot.

However, the process management in systemd is not fully compatible with the way Comet's multi-process model works. In particular, there are compatibility issues with the software updater. As a result, the above unit is (A) unable to take advantage of process group cleanup; (B) unable to auto-restart the Comet Backup agent service; and (C) after a software upgrade, Comet will keep running but the unit will remain in "exited" state.

Autostart for graphical desktop application

In the "Other Distribution" package, the graphical application is not automatically configured to start when the desktop logs in. You may add backup-interface --background as an autostart command to your desktop environment's settings.

Upgrading

The "Other Distribution" version of Comet supports upgrading the software, with some caveats:

The .run file will automatically upgrade the existing version
The software can be remotely upgraded via the Comet Server web interface.

However, the existing service will only be replaced with the upgraded version if the product brand name is unchanged.

Note: If you delete the branded Comet directory and all its contents in /opt/, this will trigger a full-reinstallation of the client software, requiring the username and password.

Uninstall

To uninstall "Other Distribution" versions of Comet, you should

Stop all Comet processes
Remove the relevant subdirectory under /opt/
Remove any custom startup scripts

Change password on Linux client

Use the 'Change Password' function in the client web interface, or change the password in the admin web interface.

Then fully uninstall and reinstall the client, using the new credential. Your device settings and Protected Items will be preserved.

Graphical desktop application for Linux

This feature is available in Comet 21.3.6 and later.

By default, the Comet Backup application for Linux runs on the command-line only. You can control and configure the application via the web interface.

If you have a graphical Linux desktop environment (e.g. GNOME / KDE / XFCE, using X11 / Wayland), it is optionally possible to run the Comet Backup desktop application. In addition to the general Linux system requirements, use of this feature has the following additional requirements:

x86_64 CPU architecture
Qt 5.7 or later
Glibc 2.24 or later

These Qt and Glibc versions are present on most Linux distributions from 2017 or later, such as Ubuntu 17.04 "Zesty Zapus", Debian 9 "Stretch", Fedora 25 Workstation, CentOS 8, and any more recent Linux distribution version.

On Debian 13 "Trixie" / Ubuntu 24.04 "Noble Numbat", you may need to install the following package dependencies:

apt-get install libqt5widgets5t64 libqt5svg5t64

On older versions of Debian / Ubuntu, you may need to install the following package dependencies:

apt-get install libqt5widgets5 libqt5svg5

On Fedora/CentOS, you may need to install the following package dependencies:

yum install qt5-qtbase.x86_64 qt5-qtsvg.x86_64

After installing Comet Backup for Linux for command-line usage, you can launch the /opt/CometBackup/backup-interface program. It is not necessary to launch this program as root; it will communicate with the installed Comet Backup background service regardless of what user account it runs as.

Windows​

System Requirements​

Windows XP / Server 2003​

Windows Vista / Server 2008​

Windows 7 / Server 2008 R2​

Windows 8 / 8.1 / Server 2012 / Server 2012 R2​

Installation​

Silent installation (Windows advanced)​

RMM Deployment Example Scripts​

Service account​

Upgrading​

Silent upgrade (advanced)​

Service account​

Uninstall​

Silent uninstallation​

macOS​

System Requirements​

Installation​

Silent Installation (macOS Advanced)​

Upgrading​

Silent upgrade (advanced)​

Uninstallation​

Linux (Debian, Ubuntu)​

Installation​

Managing the Service​

Silent install (Debian package)​

Package compatibility​

Uninstall​

Linux (Red Hat Enterprise Linux (RHEL), CentOS)​

Linux NAS (Synology)​

Installation​

Permissions​

Limitations​

After installation​

Video​

Linux (Other NAS)​

Linux (Other Distribution)​

System Requirements​

Additional Requirements​

ARM CPU support​

Timezone database dependency​

CA certificate database dependency​

Installation​

Linux Installation options​

Silent installation (Linux advanced)​

Restarting at boot​

Preserve HOME environment variable​

Start in the background​

Startup via rc.local​

Startup via rc.d​

Startup via cron​

Startup via init.d​

Startup via systemd​

Autostart for graphical desktop application​

Upgrading​

Uninstall​

Change password on Linux client​

Graphical desktop application for Linux​

Windows

System Requirements

Windows XP / Server 2003

Windows Vista / Server 2008

Windows 7 / Server 2008 R2

Windows 8 / 8.1 / Server 2012 / Server 2012 R2

Installation

Silent installation (Windows advanced)

RMM Deployment Example Scripts

Service account

Upgrading

Silent upgrade (advanced)

Service account

Uninstall

Silent uninstallation

macOS

System Requirements

Installation

Silent Installation (macOS Advanced)

Upgrading

Silent upgrade (advanced)

Uninstallation

Linux (Debian, Ubuntu)

Installation

Managing the Service

Silent install (Debian package)

Package compatibility

Uninstall

Linux (Red Hat Enterprise Linux (RHEL), CentOS)

Linux NAS (Synology)

Installation

Permissions

Limitations

After installation

Video

Linux (Other NAS)

Linux (Other Distribution)

System Requirements

Additional Requirements

ARM CPU support

Timezone database dependency

CA certificate database dependency

Installation

Linux Installation options

Silent installation (Linux advanced)

Restarting at boot

Preserve HOME environment variable

Start in the background

Startup via `rc.local`

Startup via `rc.d`

Startup via `cron`

Startup via `init.d`

Startup via `systemd`

Autostart for graphical desktop application

Upgrading

Uninstall

Change password on Linux client

Graphical desktop application for Linux