# Dual Boot w/ External HD



## jaymax (Mar 3, 2018)

I have an HP 17z platform w/ Windows 10 64 bit O/S. 
I would like to be able to boot, alternately via a USB port external HD to FreeBSD on the ext drive. 
Direction, suggestions and guidance sought.

Thanks!


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## k.jacker (Mar 3, 2018)

If there is an option in your BIOS to boot from USB first and internal second, without directly having a specify a disk, then set USB first and connect/disconnect the USB drive as needed.


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## jaymax (Mar 13, 2018)

Thanks K,
If I may continue along the same vein. There is such an option but I do have some obstacles in the path to success. As mentioned earlier I wish to boot FreeBSD from an external drive which involves installing FreeBSD there. Now the main disk runs Windows 10, [AMD CPU]. I have been able to boot the system to the Livefs of the vers. 11 Release which I used as a surrogate prior to installation. 

A `ls -aqxF /dev/ad*` shows the following
/dev/ada0p1 ; /dev/ada0p2 ;  /dev/ada0p3 ; /dev/ada0p4 ; /dev/ada0p5
[presumably the internal disk]

There is no other /dev/ada1p'n' etc.
There is a /dev/da0 and a /dev/da0s1
There is also a number of /dev/usb/ entries

I had formatted the ext, drive previously with windows file manager to a single partition, but as the disk, is not obvious to me I have no way of directing the installation, without overwriting the internal disk.

Please advice

Thanks!.


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## ShelLuser (Mar 13, 2018)

jaymax said:


> There is a /dev/da0 and a /dev/da0s1
> There is also a number of /dev/usb/ entries


That's most likely what you should be targeting. Look into `dmesg`, it'll mention what devices were found during boot and identify them.

But I don't quite understand the problem. Just boot with your live cd, log on as root, plug in the HD and it will announce itself, making it perfectly obvious which device it is.


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## jaymax (Mar 13, 2018)

I should add that `gpart show` does confirm my suspicion of the internal drive as the /dev/ada0 drive and /dev/da0 as the external disk with a ntfs single partition - OK I'll go ahead and try to format this.

THANKS again


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