wiped disk - no longer bootable

[Volker Wysk]

Zitat von Liam Proven <lproven at gmail.com>:

> 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.)

Maybe it's because I don't know anything different, but I don't feel  
like it's that complicated. Especially if you don't dig into it, but  
just use the Ubuntu installer.  ;-)

> * 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.)

So you manually set up full disk encryption, because you had to. For  
me it's the same as above: Just use the Ubuntu installer. No stress.

> 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.

There are many possible circumstances which make you want encryption...

> * 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.

You just caught me on giving up on SSD-as-a-cache. I've tried to set  
it up again, but it doesn't work. It possibly comes from incompatible  
changes in the OS (Kubuntu 18.04 versus Ubuntu 19.04).

I spent a lot of time earlier, on setting it up. Time which I don't  
want to go to waste. But I don't want to go into the details again,  
either. And when I manage to get it working again, for how long will  
that be?

So I will do something as / on SSD and /home on HDD. But I have a lot  
of pictures. It's much faster when they reside an on SSD, or a HDD  
with SSD-as-a-cache. I will have to make a setup with user files  
partially on the SSD. Using a lot of symlinks.

Cheers,
Volker