jensmander

Backup system partition(s)?

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Howdy!

 

Is it possible to backup the system partition of DSM? AFAIK this 2.4GB partition is created on every HDD/SSD when DSM is installed. So if I would have 8 HDDs how would it be done?

 

I recently saw that QuickNick plans to implement a backup function in his loader. But it would be nice to know how it could be done manually.

 

Thx & Cheers!

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Afaik the system partition is identical on all disks, so you would only need to 'backup' one system partition that could be restored to 'n' disks. In the past I have 'cloned' DSM installed disks using Macrium Reflect (free) with a boot disk so maybe you could use that (or any disk imaging software) to image just the system partition to be restored later.

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as it is a mdadm raid1 over all disks i would not take it for granted that they are the same up to the same sector/byte

maybe if you copy just the files from one disk it will work as a backup but when restoring you will need to assemble the mdadm raid1 again an overwrite it as one device

 

i would suggest to assemble the raid as a device and then make a sector copy of all the sectors in that device with dd (read sectors, write into a file), as it's only 2,4GB it will easyly fit to a usb stick, that way you recreate even partitions and boot code, pretty much the same as you can have a copy of /dev/sda, you just make a copy of /dev/md0

with that copy you will akso be able to delete the whole /dev/md0, recreate it with mdadm and then wite your copy back, the recreated /dev/md0 must have at least the same sector count (or more) to write it back

there is not much you will haveto know or to write down, the size of your image file tells you exactly how many sectors/blocks your dive had, thats all you need to know for restoring

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thats a good point, I was using the same brand/size of disks so maybe I was just lucky :smile:

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Tried it with a PE version of Macrium Reflect and it worked flawless. But - as sbv3000 mentioned - all HDDs were of the same size and modell.

 

Cheers

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If you want to back up and/or restore:

 

- Use a Linux live disk. For me, GParted recognized the MDADM arrays and mounted them.

- DO NOT make a disk image via dd or any similar block-reading tool

- DO use a tool made for backing up files, or simply moving them (rsync or even better, tar it all up)

 

To restore, just erase all files on the initial mdadm array, and extract the TAR file to it. It should restore everything stored on the system partition.

 

 

However this whole thing is unnecessary since Synology stores little to no "new" things on the system partition - it is instead kept on the volumes you create (hence why you can't install apps without a volume).

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