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Ubuntu - Disk - Ramdisk - Persisting Ramdisk Data

A Ramdisk will usually lose all data within it when turned off, or upon a reboot.

The approach is:

Save Ramdisk data to hard drive on system shutdown.
Load data from hard drive to Ramdisk on system boot.

NOTE: The directory where the Ramdisk is mounted and where the backup data will be saved must have the same file permissions.

Create backup directory

Create a directory where the Ramdisk data will be saved on system shutdown:

sudo mkdir /mnt/ramdisk_backup

Create a system service file

vi /lib/systemd/system/ramdisk-sync.service

and populate with:

/lib/systemd/system/ramdisk-sync.service

[Unit]
Before=umount.target
 
[Service]
Type=oneshot
User=root
ExecStartPre=/bin/chown -Rf peter /mnt/ramdisk/
ExecStart=/usr/bin/rsync -ar /mnt/ramdisk_backup/ /mnt/ramdisk/
ExecStop=/usr/bin/rsync -ar /mnt/ramdisk/ /mnt/ramdisk_backup/
ExecStopPost=/bin/chown -Rf peter /mnt/ramdisk_backup
RemainAfterExit=yes
 
[Install]
WantedBy=multi-user.target

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Table of Contents

Ubuntu - Disk - Ramdisk - Persisting Ramdisk Data

Create backup directory

Create a system service file