Re: [gentoo-user] USB external hard drives

[Mick]

On Monday, 15 April 2019 17:03:43 BST Laurence Perkins wrote:
> On Sun, 2019-04-07 at 12:09 -0400, james wrote:
> > Hello,
> >
> > I have a windows pro 10, bargain HP laptop, with a 1 T mechanical
> > internal drive. New. I'd like to make the system dual boot off of
> > an external (USB3) SSD, that is exclusive for Gentoo. I have about
> > 500M of person and /usr/local files on other gentoo systems that I'd
> > like to DD over to the new drive.
> >
> > 1. I'm not sure what file system to use. I' like to use btrfs, but
> > I'd need some sort of guide to set that up.
> >
> > OR
> >
> > 2. If I used ext-4 what should the formatting and partition table
> > look
> > like?  Ideally, I'd like to put the 'gentoo on a partition to the
> > native
> > hard drive. and be able to put /usr/local and /projects only on the
> > the new SSD external only, so I can move those mount point partitions
> > to various gentoo systems.
> >
> >
> > Perhaps I'll get (2) external SSDs and put gentoo on one, just for
> > the
> > HP laptop and the second one set up just for /usr/local and
> > /projects.
> >
> >
> > I'm just thinking out loud and ideas or discussions are welcome. I'm
> > not
> > the sharpest tack, when in comes to windows pro 10..... or complex
> > file
> > system setups.
> >
> > All my systems are AMD64, the new laptop is Rizen 5 2500-U
> >
> >
> > James
>
> There are not really any differences to how you'd format an external
> disk compared to an internal one on modern systems.  If you want
> different sections of the system on different drives you just set that
> up in fstab so the system attaches everything to the proper places on
> boot.  Having your linux on a separate disk that you can disconnect
> when using Windows has the advantage of avoiding Windows' propensity to
> scribble all over things it really shouldn't be touching, like your
> boot setup.
>
> Btrfs/ZFS have some advantages compared to more traditional
> filesystems, but they are slower.  It is handy to be able to just plug
> in another drive and add it to the storage pool if you temporarily need
> more space for some project though, and depending on what kind of data
> you spend most of your time shuffling the built in compression option
> can improve performance quite a bit.  Ext4 on the other hand has a
> longer track record and supports built-in encrpytion.  So compare the
> features and see which fits your use case better.  Btrfs is pretty
> stable at this point, I use it almost exclusively and haven't had it
> eat any data in years, plus the data checksums have saved me from
> corruption a few times when drives went marginal but didn't fail
> outright, but you have to have it keeping multiple copies for that to
> work (Raid or dup.)
>
> LMP

Some additional comments to consider for your new Gentoo installation.

1TB left to MS Windows is probably a major waste of space, unless you use the 
OS on a regular basis and store a lot of data on its main partition.  
Therefore you may want to create a backup of the complete MSWindows drive and 
then shrink it down to create space for Gentoo:

a) Disable the Windows 10 page file to get rid of pagefile.sys.[1]
b) Disable hibernation by running 'powercfg -h off' in cmd.exe to get rid of 
hyberfil.sys.
c) Temporarily disable automatic Windows Updates and restart.
d) Defrag its main partition.[2]
d) Shrink its main partition to say 100GB or more[3], depending how much of it 
you want to use in the future - it always increases in size with updates over 
the years and additional applications.  Note, the built in partition manager 
won't shrink the partition by more than 50% of its original size, you may have 
to use a 3rd party MSWindows tool, or a LiveCD/USB like gparted to get a 
better result.
e) Restart to make sure all works as intended, then shutdown completely.[4]
f) Boot with Live gentoo or sysrescuecd to partition the rest of the drive and 
install your Gentoo OS.
e) Installing GRUB will take care of dual booting both OS' and is definitely 
simpler than chainloading Gentoo from MSWindows after you edit the latter's 
boot options with Bcdedit.
f) Re-enable Windows Updates and page file.

There's nothing wrong with running Gentoo off a USB drive if this is what you 
want to do, but the performance of a SATA III ought to be better than a USB 3 
in most cases.  Perhaps an e-SATA would be a better option for a separate 
external drive, as long as your various hardware have eSATA ports.


[1] https://www.howto-connect.com/tweak-paging-file-for-better-windows-10-performance/

[2] https://support.microsoft.com/en-us/help/4026701/windows-defragment-your-windows-10-pc

[3] https://win10faq.com/shrink-partition-windows-10/

[4] https://www.howtogeek.com/349114/shutting-down-doesnt-fully-shut-down-windows-10-but-restarting-it-does/

-- 
Regards,
Mick