wiped disk - no longer bootable

[Liam Proven]

On Sat, 13 Jul 2019 at 15:57, Volker Wysk <post at volker-wysk.de> wrote:

> "beyond the skills and/or imagination of those trying to help you."
> denotes my SSD-as-a-Cache, isn't it?

Not *just* that, no.

LVM + encryption + ssd-as-cache = fear

* I don't like LVM and don't use it. It makes life too complex. IMHO
it is only worth it on big servers with multiple hard disks.

(I speak as someone who has made a career out of understanding and
mastering difficult IT technology since the 1980s. I can judge when
something is elegant and when it's a nasty kludge. In my professional
opinion, LVM is a nasty kludge. It has too many layers: a partitioning
scheme, then LVM, then partitions on LVM, then a filesystem on the
partitions. That is nasty. This is why more modern filesystems such as
ZFS *exist*: they merge the volume management and partitioning and
filesystem into one layer. This removes a lot of duplication and makes
them easier to understand, to implement, and in theory, more robust.
Btrfs does some of this but IMHO not enough. Even Red Hat has
acknowledged this and as a result it is developing its own new volume
manager, Stratis, which merges LVM and XFS into one unit.)

* I don't like disk encryption and don't use it.

(E.g. at my previous job at a Linux vendor, I was issued a very nice-
then state-of-the-art Thinkpad X240 with a ½ TB SSD. But company rules
meant it had to have full disk encryption (FDE). It took me 3 days to
get this working -- that's after ½ century of Linux knowledge, and,
you know, _getting a job at a Linux vendor_ -- and when it worked the
machine became as slow as if it had a hard disk.)

FDE is arguably worth it if *both* [a] you work with confidential info
and [b] you use a notebook which could be lost or stolen. On a desktop
or on a home computer, forget it.

* SSD as cache: why?

The easy way is root on SSD, /home on HD. This gives great speed for
most jobs and can be tuned with tools such as compcache, tmpfs,
swapspace, zram and so on to ensure that temporary work files are held
on nice fast media while you have a dead simple, easy-to-troubleshoot
disk setup.


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