Hi,
To backup the internal sd card, is the only way to remove it and do a backup on another machine?
Conceptually, there are 2 methods of backing up an SD card:
- Copy the entire SD card (as a device, not partition(s)) to an SD card image file
- Copy specific (or all) files and directories, as files and directories
The first method is only appropriate when the SD card is not mounted. Therefore, to copy your internal micro-SD card in this way you should boot from an external device (e.g. USB stick, or USB / eSATA hard drive),
or remove the micro-SD card to copy it using another PC or device. Then use dd to copy. (dd can also be used to copy at the partition level, instead of device level, but that is a variation of this method).
The second method requires that the micro-SD card be mounted, and would allow you to specify only certain parts of your filesystem to be backed up - for instance
/home. It is not recommended that the files you are copying be open at the time of the copy, but if you have a clear idea of what files you are copying you can take steps to close them beforehand.
The dd method is popular and simple, and is practical so long as SD card sizes remain a fraction of the size of other storage devices. If the time comes that you have a 256G SD card, you'll probably be looking towards some sort of mirroring or variation of the second method.
I do got a separate external SD card but don't know if this can be used to boot from instead of the internal one.
There are threads here that discuss booting from alternate devices. This requires changes to environment variables, therefore you
must have a JTAG unit. See the
Dreamplug booting board or
here
