nexus-backup-restore

Version 20230424

Scripts to backup/restore home folder and to backup and compress the entire microSD card.

Backup and Compress Home Folder to a USB disk (nexus-backup-restore.sh)

This script will back up the contents of your home folder on your Nexus Pi to an external (USB attached) disk or flash drive.

This script is handy when you're moving to a new image. In that case, run it on your Pi to create a backup of your home folder, then insert the SD card with the new image, run this scrip again and insert the USB stick with your backup, click Restore and follow the prompts.

The script will also backup and restore the user's crontab.

Make a Compressed Image of the MicroSD Card and copy it to a USB Disk (sdbackup.py)

This script will backup and compress the entire microSD card to an external (USB attached) disk or flash drive. It can be run from the command line and do scheduled backups via a cron job, or be run interactively as a GUI.

You might ask: Doesn't Raspbian already have an SD clone utility? Yes, it does. that utility makes an exact copy of the SD card to another SD card. sdbackup.py makes a compressed backup of the microSD card to almost any external disk. That backup file can then be burned to a microSD card if desired. This allows you to make regular (automated, if desired) backups and have multiple date-stamped backup files to choose from.

The script creates a file in the destination disk that the user selects. The backup file name is of this format:

$HOSTNAME_xGB_YYYYMMDDTHHmmSS.gz

where $HOSTNAME is the hostname of the Raspberry Pi., x is the size of the microSD card that's being backed up (the script determines this), YYYY is the year, MM the month, DD day of the month, T separates the date from the time, HH the hour, mm the minute, and ss the second when the backup was started. gz is the file extension, indicating a 'gzipped' file.

The USB drive containing the backup file can then be moved to any Mac or Linux or Windows PC and the backup gz file can be burned to a microSD card using Balena Etcher. The gz file does not have to be decompressed first. Balena Etcher automatically decompresses it.

Note that when you burn the backup gz file to a microSD card, that card must be the same size as or larger than the microSD card from which the backup was made. That's why I embedded the original microSD card size into the file name.

On a Raspberry Pi 4B with a 16GB microSD card (about half full) with 4GB RAM and a USB3 HDD attached to a USB3 port, the backup takes just over an hour and results in a gz file of about 6GB.

Prerequisites

The USB attached external disk/flash drive must be formatted as exfat, which supports files larger than 4GB. exfat formatted disks can be read by Linux, Mac and Windows PCs. ext4 formatted disks are also supported, but those disks cannot be read by Macs or Windows PCs. The script will print an error message if the external drive uses a format that does not support files larger than 4GB.
The volume name of the USB external disk/flash drive must not contain spaces.
There must be adequate space on the external disk/flash drive. The script will make a guess at how much space will be needed on the external drive for the compressed image and will print an error if it determines that there is not enough space available.
The script must be run with root privileges (sudo).
The Raspbian OS must have the exfatprogs package installed. This is installed by default on the NexusDR-X image.
NOTE: The Raspbian OS by default automatically detects disks plugged in to USB and in most cases, a shortcut will automatically appear on the desktop for that disk. You'll also likely see a "Removable medium inserted" window pop up when the disk is attached to a USB port. Just click Cancel to close that window. USB attached drives appear as:

/media/$USER/name-of-drive

where $USER is usually pi.

Run from the command line

Run the script with the -h to see the available options. For example:

  pi@buildpi:~ $ sudo sdbackup.py -h
  usage: ddbackup.py [-h] [-v] [-d STRING]

  Backup & compress Raspberry Pi Image

  optional arguments:
    -h, --help            show this help message and exit
    -v, --version         show program's version number and exit
    -d STRING, --destination STRING
  			  Destination path/location for the backup

If sdbackup.py is run with the -d or --destination option followed by the destination location, the script will run entirely on the command line. No GUI will open.

For example, to backup my microSD card to my USB attached disk at /media/pi/500GB, I would run:
```
  sudo sdbackup.py -d /media/pi/500GB
```

Run as a `cron` job

You can set up your Pi to do automatic unattended backups of your microSD card via cron. In this example, I'll backup up my microSD card to a USB disk drive connected to my Pi. My external disk appears as 500GB on my desktop, so the path to that disk is: /media/pi/500GB.

I'll set up the script to run every Sunday at 2:13 AM. The script will also delete backups older than 14 days and verify that the external disk is attached before attempting to run the backup.

Run crontab -e to open the cron editor. You might be prompted to select an editor. nano is easiest to use.
Add the following line to the end of the file (IMPORTANT: change /media/pi/500GB to match your attached disk and adjust the time/frequency as desired):
```
  13 2 * * 0 mountpoint -q  /media/pi/500GB && (sudo find /media/pi/500GB/$(hostname)_*GB_*.gz -maxdepth 1 -type f -mtime +14 -delete; sudo sdbackup.py -d /media/pi/500GB >/dev/null 2>&1)
```
The line above breaks down as follows:
- 13 2 * * 0: Run this script at 13 minutes after 2AM any date of the month (the 1st *) any month (the 2nd *) every Sunday (the 0).
- [ -d /media/pi/500GB ] &&: Verify that /media/pi/500GB exists and is a directory, and if it is (&&), execute the remainder of the line. If /media/pi/500GB is not present or is not a directory, the job ends here.
- (sudo find /media/pi/500GB/$(hostname)_*GB_*.gz -maxdepth 1 -type f -mtime +14 -delete;: Look for files (-type f) matching this criteria: /media/pi/500GB/$(hostname)_*GB_*.gz. If any matching files are older than 14 days (-mtime +14) , delete (-delete) them. Don't look for any matching files in any subdirectories (-maxdepth 1), then once that's done (;)...
- sudo sdbackup.py -d /media/pi/500GB >/dev/null 2>&1): ...run the backup script and send any printed output from sdbackup.py to the bit bucket (>/dev/null 2>&1).
Save the file and exit the editor. The script will run automatically at 2:13AM every Sunday.

Run the GUI

If you don't provide any arguments, sdbackup.py will attempt to start the GUI. It can be run at Raspberry > Accessories > SD Compressed Backup.

A dialog will appear that will prompt you to select the destination for the backup. Navigate to the desired destination, making sure the full destination appears in the Selection: field. Click OK once you've selected the destination.
If the destination is valid and has enough available space, another dialog window appears. Click Start to begin the backup. You can monitor the backup progress via the progress bar and the % complete indicator.
When the backup has completed, you'll see a message with the destination backup file and the elapsed time to backup the microSD card. Click Quit to close the script. Clicking Quit while the backup is running will abort the backup and delete the backup file.

AG7GN/nexus-backup-restore