[ale] to lvm or not lvm is my dillema

[Phil Turmel]

I use LVM on all of my physical machines, including my daily driver, for 
all the reasons JD lists.  Plus:

With two NVMe sticks in my laptop, I can selective apply RAID1 to only 
the volumes I need to survive a storage failure.  Other stuff, like VMs 
that can be reconstructed, I leave as non-raid.

I also use LVM snapshots for certain backup tasks (postgres DBs in 
particular).

On 1/2/26 08:49, DJPfulio--- via Ale wrote:
> It depends on you, your needs and whether you want lots of control.  
> With control comes complexity and flexibility.  Only you can decide.
> 
> Think of it this way.
> LVM is like a transmission in an 18-wheel truck.  When you need it, you 
> really need it, but you'll have to learn how to use it.
> 
> If you just want to get into a little sedan, perhaps an automatic 
> transmission is more desirable, but you lose flexibility that you may 
> never need and you certainly avoid the added complexity.
> 
> If you were trying to become a full-time server admin for a new career, 
> I'd say learn LVM and ZFS. They are good skills to have.  LVM on Linux 
> is modeled after the UNIX LVM version which are mostly stolen from 
> Veritas. If you already know Veritas Volume management, then the 
> transition will be easy.
> 
> But if you don't know Veritas and have little interest in being a Linux 
> Server admin, then LVM may just bring more complexity that you don't 
> care to have.
> 
> If you are still curious, why not setup a virtual machine and choose LVM 
> during the install?  Try it out, don't just accept the defaults.  
> Actually use it for common things like expanding and reducing file 
> systems and a mock migration to another system.  Migrations are one 
> thing that LVM makes really easy - it is almost laughable how much 
> easier migrations can be from a 256G HDD to a HDD that is larger - all 
> with very little downtime.  The system can be running full speed during 
> the migration and if you don't change the boot partition, you don't need 
> to reboot at all.   In a business, this can be extremely useful.  Most 
> home users don't care much about having to reboot 5 times in a day.
> 
> Always remember, just because LVM will let you do something, that 
> doesn't mean it is a good idea.  People do dumb things with LVM all the 
> time.  I have.  And I have the data loss history to prove it.  But I've 
> learned from those mistakes and can't imagine setting up a new physical 
> storage system without LVM.
> 
> Here's an LVM layout on 1 of my systems (not showing the other 16TB of 
> storage), just the core stuff:
> NAME                              TYPE FSTYPE       SIZE FSAVAIL FSUSE% 
> LABEL       MOUNTPOINT
> nvme0n1                           disk            931.5G
> ├─nvme0n1p1                       part ext2           1M
> ├─nvme0n1p2                       part vfat          50M   43.8M    
> 12%             /boot/efi
> ├─nvme0n1p3                       part ext4         700M  304.2M    
> 47%             /boot
> └─nvme0n1p4                       part LVM2_membe 930.8G
>    ├─vg01-swap01                   lvm  swap         
> 4.1G                            [SWAP]
>    ├─vg01-root01                   lvm  ext4          35G   24.5G    
> 23%             /
>    ├─vg01-var01                    lvm  ext4          20G    8.6G    
> 51%             /var
>    ├─vg01-tmp01                    lvm  ext4           4G    3.6G     2% 
> tmp01       /tmp
>    ├─vg01-home01                   lvm  ext4          40G   23.8G    35% 
> home01      /home
>    ├─vg01-libvirt--01              lvm  ext4         137G    2.8G    98% 
> libvirt--01 /var/lib/libvir
>    ├─vg01-lxd--containers--01      lvm                30G
>    ├─vg01-usrv2404                 lvm                15G
>    └─vg01-TinyCore                 lvm                 1G
> 
> Note how I don't have the all the available storage assigned?  That's an 
> important aspect for LVM's flexibility.  Also, I use LVM LVs to directly 
> provide block storage to virtual machines. That storage isn't mounted on 
> the host computer.  That's why the last 3 rows don't have full 
> information. The host computer doesn't know what is happening inside 
> those LVs.
> 
> LVs, as shown above, can be thought of as really smart partitions. LVs 
> can be modified while the file system inside them is active and busy.
> 
> If that layout seems overly complex, that isn't wrong.  But the specific 
> things I've split off into their own LVs generally use specific, 
> different, mount options, to provide a slightly more secure base-OS.
> 
> In the end, it is your choice.