installing ubuntu from bootable usb, using lvm

bruce badouglas at gmail.com
Fri Jul 18 15:09:21 UTC 2025 

Hi Robert.

Ok, so you're basically saying, I should only install apps on the
internal drive where the OS will reside. Is that correct?



On Fri, Jul 18, 2025 at 10:42 AM Robert Heller <heller at deepsoft.com> wrote:
>
> At Fri, 18 Jul 2025 10:28:26 -0400 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
>
> >
> > Hi.
> >
> > Thanks for all the replies.
> >
> > Since my goal, is to install the OS onto the internal drive, but at
> > the same time, have the additional apps, and work done on the external
> > drive.
> >
> > Would it perhaps make more sense (easier) to setup/partition both
> > drives during the install process.
> >
> > The 2nd drive would more or less be setup to mimic areas of the
> > internal drive where apps are installed:
> >  /usr/bin
> >  /var/www
> >  etc..
>
> Don't do this!!!!!
>
> >
> > The areas/partitions on the 2nd drive would be setup in the install,
> > and then after install, would be symlinked to the internal drive
> > locations.
> >
>
> Don't do this either!!!
>
> > This would preserve the installed location for all the process/apps
> > installed on the laptop. At the same time, the internal drive would
> > have the OS, while all the apps/processes would be on the external
> > drive.
> >
> > The fstab would still have to be set to mount everything at reboot,
> > and of course, this is still fragile.
>
> Use fstab to mount only the internal disk's volumes
>
> Use automount for the external disk's volumes.
>
> >
> > Of course, the optimal solution would be a larger internal drive, with
> > an external backup.
>
> Yes, but that is NOT always going to be posible or practical.
>
> >
> >
> > On Fri, Jul 18, 2025 at 8:39 AM Robert Heller <heller at deepsoft.com> wrote:
> > >
> > > At Fri, 18 Jul 2025 08:18:15 -0400 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
> > >
> > > >
> > > > Hi Sam.
> > > >
> > > > In all honesty, I'm not sure I do (which is why talking directly with
> > > > someone would be seriously helpful).
> > > >
> > > > I "think" I need LVM in order to be able to "tie" the
> > > > internal/external drives together in a manner that allows the OS to
> > > > reside on the internal ssd, while having the data on the external
> > > > drive. The connection/coupling of the external drive/dirs would be via
> > > > the LVM/symlink process.
> > >
> > > No you don't need to "tie" the internal/external drives together. Yes, LVM
> > > *can* be used as a "simple" RAID0-like hack to join two (or more) disks into a
> > > single volume group. But I don't think you really want to do that. Using LVM
> > > that way makes more sense if you have multiple "small" internal disks (or
> > > maybe an external enclosure with multiple "small" disks). Binding an internal
> > > *laptop* disk and with an external disk is just asking for trouble.
> > >
> > > You *can* create multiple LVM volume groups. In your case one for the internal
> > > disk and another one for the external disk.  You can then carve out logical
> > > volumes for different uses.  Put the core system file systems (/boot, swap, /,
> > > /var/www, /home, etc. on the internal drive).  This will allow the laptop to
> > > boot up and be usable without needing the external drive connected.  The
> > > external drive can be carved up into various data file systems.  You can use
> > > automount (sudo apt install automount) to mount them on demand.
> > >
> > > >
> > > > And to your point about needed to always then carry the external
> > > > "working" drive or you have a brick, yep!  As I mentioned, fragile.
> > > >
> > > > If you are in the US/North/South America, let's talk for a min!
> > > >
> > > > thanks
> > > > -bruce
> > > >
> > > >
> > > > On Fri, Jul 18, 2025 at 7:28 AM Sam Varshavchik <mrsam at courier-mta.com> wrote:
> > > > >
> > > > > bruce writes:
> > > > >
> > > > > > So far, haven't found any tutorial with screen shots showing the
> > > > > > Install process invoking the LVM process (volGroup, LogicalVol, etc)
> > > > >
> > > > > Let's take a step back. Why do you believe you need an LVM?
> > > > >
> > > > > > Does anyone have any pointers/sites to illustrate this process?
> > > > >
> > > > > LVM is one of those things which are only needed if there's specific
> > > > > requirement, knowledge, and understanding what an LVM is, what it does, and
> > > > > how it works.
> > > > >
> > > > > Especially on a laptop.
> > > > >
> > > > > > I've seen a few sites that illustrate the partition setup:
> > > > > > example partition
> > > > > >
> > > > > > /dev/sda --- internal 128G ssd
> > > > > >  /dev/sda1  ext4  /boot     1G
> > > > > >  /dev/sda2  ext4  /root     1G
> > > > > >  /dev/sda3  swap           10G
> > > > > >  /dev/sda4  ext4  /       110G
> > > > > >
> > > > > > /dev/sdb --- exetrnal 1TB hdd
> > > > > >  /dev/sdb1  ext4  /etc     1G
> > > > > >  /dev/sdb2  ext4           10G
> > > > > >  /dev/sdb3  ext4  /       110G
> > > > > >
> > > > > > But then the examples, drop into "go ahead and then install"
> > > > >
> > > > > Right, and marry the laptop to the hard drive, forever. Any time you want to
> > > > > take your laptop somewhere you must lug this hard drive with it. Without it,
> > > > > your laptop becomes an unbootable brick. Because it contains the friggin' /
> > > > > filesystem.
> > > > >
> > > > > Because that's how LVM works.
> > > > >
> > > > > So, again, why do you think you need to use LVM?
> > > > >
> > > > > --
> > > > > ubuntu-users mailing list
> > > > > ubuntu-users at lists.ubuntu.com
> > > > > Modify settings or unsubscribe at: https://lists.ubuntu.com/mailman/listinfo/ubuntu-users
> > > >
> > >
> > > --
> > > Robert Heller             -- Cell: 413-658-7953 GV: 978-633-5364
> > > Deepwoods Software        -- Custom Software Services
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> > >
> > >
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> >
>
> --
> Robert Heller             -- Cell: 413-658-7953 GV: 978-633-5364
> Deepwoods Software        -- Custom Software Services
> http://www.deepsoft.com/  -- Linux Administration Services
> heller at deepsoft.com       -- Webhosting Services
>
>
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