# Backup boot USB key?



## cwhitmore (Apr 28, 2009)

I'm in the process of setting up an iSCSI SAN using OpenFiler. (Tried using FreeNAS, but it won't do clustering.)
Here is my question. I have OpenFiler booting from a 2GB USB key. I'd like to make a backup of the key onto another key (same size), but there doesn't seem to be an easy way to do this in Windows. I tried SelfImage, but the USB keys have slightly differently partition sizes (even though the model and size keys are exactly the same), so it won't work.

Is there a way to do this in FreeBSD? Maybe a port?


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## phoenix (Apr 28, 2009)

Boot into FreeBSD.

Connect second USB key.  Note which device node is created for it.  Check output of *dmesg*.  Should be something like da1.

Then, just do a bit-for-bit copy of the first USB key to the second, using dd (this assumes the first key is called da0 and the second key is called da1):

```
# dd if=/dev/da0 of=/dev/da1 bs=2048
```

Then try booting off it, to make sure the boot blocks transferred over correctly.


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