installing ubuntu from bootable usb, using lvm

Robert Heller heller at deepsoft.com
Fri Jul 18 18:11:27 UTC 2025 

At Fri, 18 Jul 2025 11:26:45 -0400 "Ubuntu user technical support,? not for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:

> 
> got it.
> 
> problem with that, I don't want to have all apps/os on the 128 internal.

128G should be more than enough for everything needed for the system to boot 
up.  Application *binaries* are not going to be terribly large.


> 
> with databases, test apps, etc..  it could fill up.  which is why I've been
> looking at the ability to symlink/lvm.

Since "Test Apps" are not going to be part of the operating system it should 
be fine for them to be on the external drive.

> 
> why are you suggesting not doing this?  aside from the facility.  as I've
> mentioned other sites have suggested symlinking as a workable method.  but
> again, I have 0 insight into the authors backgrounds.

You don't want to make the *laptop* unbootable (effectiely "bricked") without 
the *external* hard drive connected.  If (really *when*) you find yourself 
with the laptop without the external hard drive, you would be "up shit's 
creek".  I suspect that the sites you are looking at involve desktop machines, 
probably with more than one *internal* disk.  Or else a *permanently connected 
"external" hard drive or a NAS or something like that.  Desktops and fixed 
servers are in a somewhat different situation from a *laptop*.  A laptop is 
meant to be carried around and therefore, depending on any sort of *external* 
hardware is going to bite you sooner or later.
> 
> thanks!
> 
> 
> On Fri, Jul 18, 2025, 11:20 AM Robert Heller <heller at deepsoft.com> wrote:
> 
> > At Fri, 18 Jul 2025 11:09:21 -0400 "Ubuntu user technical support,? not
> > for general discussions" <ubuntu-users at lists.ubuntu.com> wrote:
> >
> > >
> > > 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?
> >
> > Yes, that is correct.
> >
> > Just use the external drive for data.
> >
> > >
> > >
> > >
> > > 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
> > > > > > http://www.deepsoft.com/  -- Linux Administration Services
> > > > > > heller at deepsoft.com       -- Webhosting Services
> > > > > >
> > > > > >
> > > > > > --
> > > > > > 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
> > > > http://www.deepsoft.com/  -- Linux Administration Services
> > > > heller at deepsoft.com       -- Webhosting Services
> > > >
> > > >
> > > > --
> > > > ubuntu-users mailing list
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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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> > ubuntu-users mailing list
> > ubuntu-users at lists.ubuntu.com
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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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