Concept for new installation

[nobbert]

It finally works with systemd-services!
I did, what was documented here: https://askubuntu.com/questions/1335...n-ubuntu-21-04


Edit:
Sometimes, it seems not to work... :-/

[Virginio Miranda]

Yes, it is possible by script and using systemd, but depending on the situation it may not work. For example: using mysql. The trick will not work because you will have to stop mysql first. Think about it. It may be better to do it manually on the command line.

[nobbert]

Ok, I've followed Virginio's link to Digital Ocean on how-to-RAID.
That solved the "problem" of /dev/md0 turning into /dev/md127 but the shutdown didn't work either.

But now, I've got a glimpse of a solution:
1.) sudo umount /dev/md0
2.) sudo mdadm --stop /dev/md0
After these two commands (and especially the second one!), the system shuts down or reboots just as expected.

But how to implement these two commands into a shutdown-routine? Mess around with systemd?

By the way, I'm still waiting for a CPU-fan which fits into my casing... but that should be delivered in 2-3 weeks, finally

[Virginio Miranda]

Gnah! I didn't expect problems like these. The CPU-fan which should hopefully fit inside the case won't be here until 25.02., so I have to wait some more weeks

Strange about the swap... it reads like you said, but parted tells me, I organized it correctly...

I created the RAID with mdadm and it is a RAID1 with 2 similar disks. No problem with mounting, no problem with unmounting, but with shutting down since I installed the RAID.
shutdown -v has no verbose output-effect (other than shutting down to an unresponsive system) and is not documented on the manpage.

This is not only a question of mounting and unmounting and shutdown, but raid1 array has to be in stopped state before shutdown the PC. It seems there is a problem on it. This is why i asked you to explain how you created the raid array.

i have the impression you did not do it correctly. That statement : " The HDD-RAID is mounted in /home/username/RAID, so my own files are secure on the RAID, while the system's userfiles are on the faster SSD " guide me to that.

Compare what you did with the instructions of Digital Ocean on the link bellow:

https://www.digitalocean.com/communi...a-raid-1-array

And yes, Try to mount on /mnt. Only by convention.

[jlittle]

It seems you create a Swap of 512 Megas on 500 GB SSD. This is the default for Kubuntu 24.04.

Indeed, for me calamares always creates a swap file of 512 MB (or maybe MiB), even if I've set up a swap partition.

[nobbert]

Gnah! I didn't expect problems like these. The CPU-fan which should hopefully fit inside the case won't be here until 25.02., so I have to wait some more weeks

Strange about the swap... it reads like you said, but parted tells me, I organized it correctly...

I created the RAID with mdadm and it is a RAID1 with 2 similar disks. No problem with mounting, no problem with unmounting, but with shutting down since I installed the RAID.
shutdown -v has no verbose output-effect (other than shutting down to an unresponsive system) and is not documented on the manpage.

[Virginio Miranda]

So, I built up the new machine, but the CPU-fan doesn't fit into the case - the case will be left open until a slimmer fan arrives...

I installed /boot/efi and / and /home on the SSD with 500 GB, swap is on the SSD with 256 GB.
The HDD-RAID is mounted in /home/username/RAID, so my own files are secure on the RAID, while the system's userfiles are on the faster SSD.

After installing the RAID, I have the problem that the system doesn't shutdown anymore.
I just get an unresponsive system where I can move the mouse, but nothing more...


"vmstat -s" for an absolutely Not note stressed machine:

vmstat -s
65037904 K total memory
1280992 K used memory
588648 K active storage
396944 Component inactive memory
63539788 K free storage
130828 K buffer memory
708504 K Outsourcing memory cache
524284 K Total retrieval memory
0 K used retrieval memory
524284 K free swap storage
349 non-nice user CPU ticks
1 nice user CPU ticks
939 System CPU Ticks
65472 id id cPU ticks
11921 I/O-Warten CPU Ticks
0 IRQ CPU ticks
15 softirq CPU ticks
0 Stolen CPU ticks
0 non-nice guest cpu ticks
0 nice guest cpu ticks
603816 K paged in
35016 K paged out
0 pages swapped in
0 pages swapped out
337126 Interrupts
316891 CPU context switches
1737706446 Start time
1955 Forks

Ok this is an absolutely " Not note stressed machine ", so this meaning nothing. You need to stress the system like i said. But before do that, look at the " 524284 K free swap storage " number. Are you sure you create a Swap on 256 GB SSD? It seems you create a Swap of 512 Megas on 500 GB SSD. This is the default for Kubuntu 24.04.

Check this. Type on Konsole:

swapon -s

About the Raid, i'm curious. May you explain how you create the raid setup and what kind of raid is it?

[nobbert]

The vmstat wasn't supposed to help troubleshooting the shutdown problem, Virginio Miranda asked for it (under stress).

[oshunluvr]

Your vmstats aren't useful in troubleshooting why your RAID won't unmount - at least that's what I assume is happening. You need to know why it's hanging before anything can be fixed.

Next time you shutdown, try hitting the ESC key and see what's hanging. Or better yet, hit CTRL-ALT-F1 (log out of your user first) and enter sudo shutdown -v -h now and watch what happens. Recording the scrolling text on your cellphone could be helpful, but likely, the text will stop streaming once the problem process is reached. Then post that here...

[nobbert]

So, I built up the new machine, but the CPU-fan doesn't fit into the case - the case will be left open until a slimmer fan arrives...

I installed /boot/efi and / and /home on the SSD with 500 GB, swap is on the SSD with 256 GB.
The HDD-RAID is mounted in /home/username/RAID, so my own files are secure on the RAID, while the system's userfiles are on the faster SSD.

After installing the RAID, I have the problem that the system doesn't shutdown anymore.
I just get an unresponsive system where I can move the mouse, but nothing more...

"vmstat -s" for an absolutely not stressed machine:

$ vmstat -s
65037904 K Gesamtspeicher
1280992 K benutzter Speicher
588648 K aktiver Speicher
396944 K inaktiver Speicher
63539788 K freier Speicher
130828 K Pufferspeicher
708504 K Auslagerungsspeicher-Cache
524284 K Gesamt-Auslagerungsspeicher
0 K benutzter Auslagerungsspeicher
524284 K freier Auslagerungsspeicher
349 nicht-nice Benutzer-CPU-Ticks
1 nice-Benutzer-CPU-Ticks
939 System-CPU-Ticks
65472 Untätig-CPU-Ticks
11921 E/A-Warten-CPU-Ticks
0 IRQ-CPU-Ticks
15 softirq-CPU-Ticks
0 Gestohlene CPU-Ticks
0 non-nice guest cpu ticks
0 nice guest cpu ticks
603816 K paged in
35016 K paged out
0 pages swapped in
0 pages swapped out
337126 Interrupts
316891 CPU context switches
1737706446 Startzeit
1955 Forks

[Virginio Miranda]

I will build up the new system with 64 GB at first and post the vmstat-output from that system. This will take 1-3 weeks. I'll keep you updated.
The old one with 16 GB will replaced, no matter what.

No worries nobbert .

64 GB of ram memory will be more that enough for your usage. There will be a lot of memory left.

Good luck.

[nobbert]

I will build up the new system with 64 GB at first and post the vmstat-output from that system. This will take 1-3 weeks. I'll keep you updated.
The old one with 16 GB will replaced, no matter what.

[Virginio Miranda]

One problem with my old system is, that it makes screeching noises. So I definitely want to replace at least the power supply.
And I guess, today's hardware (MB, CPU, RAM) will have better performance. At that time, I didn't have too much money and just bought low/mid-price range, whereas now I can invest a bit more.

vmstat tells me, that (without pic/vid-software open) I use 4 of 16 GB RAM and have about 7 GB free memory - just for the system running with some browsertabs and an mp3 playing.

I guess, I will go for the 64 GB RAM now and swap to this separate 256 GB SSD.
When the RAM gets used up and is sold cheaper in the future, I will max it to 128/192 GB which the mainboard can handle.
And if the swap-SSD ever gets broken, I can simply replace it for 26 EUR and don't have to worry about anything.

Ok, but there are more important info on $ vmstat -s output.

Stress the system. Open 15 pages with your browser, play mp3, go to youtube and play 4k video 60 fps. Do anything else you use to do in your daily usage.

go to Konsole and type $ vmstat -s again.

Copy and paste the entire output here please.

[nobbert]

One problem with my old system is, that it makes screeching noises. So I definitely want to replace at least the power supply.
And I guess, today's hardware (MB, CPU, RAM) will have better performance. At that time, I didn't have too much money and just bought low/mid-price range, whereas now I can invest a bit more.

vmstat tells me, that (without pic/vid-software open) I use 4 of 16 GB RAM and have about 7 GB free memory - just for the system running with some browsertabs and an mp3 playing.

I guess, I will go for the 64 GB RAM now and swap to this separate 256 GB SSD.
When the RAM gets used up and is sold cheaper in the future, I will max it to 128/192 GB which the mainboard can handle.
And if the swap-SSD ever gets broken, I can simply replace it for 26 EUR and don't have to worry about anything.

[Virginio Miranda]

The question is not, if I need more RAM in the future - the question is, when will I need more RAM.
So, I'd rather pay a little extra now and avoid the problem of not getting some RAM with the same CL-values in the future.

What do you think about swapping on this cheap, little 256 GB SSD instead of the root-SSD? Brillant idea or not?

So, first you steal our words and then you misspell them!

Hmmm... I might as well start with 64 GB RAM and sell those modules later and get matching sets of bigger (and faster?) modules (which might be even cheaper in the future?). That would save me 200 EUR now.

I'm not even sure, how much RAM I really need. I just figured, my recent system is 10 years old with 16 GB, so maybe invest a little and get 4x or even 8x the RAM-size.

Well, you got the answer yourself. If you dont know how much ram do you really need, how can i tell you if the 256 GB SSD is a brillant idea for swap inside root-SSD or not? Do you like to listen about theory? Google for it.

In my situation i said it before: I dont use swap. I have 32 GB of memory ram, and is more than enough for my usage. My 512 MB of swap is on root-SSD, but i have to tell you, my swap is zero. My system dont use swap. It runs 24/7, dont power off, i do not make use of hibernate and i do not make a photo, video and music edition.

Your situation is different. You dont know how much ram do you need and what do you really need. I am not to be rude with you, Only try to help you.

I can see that your recent system is 10 years old with 16 GB and you said that is running kubuntu since 2007. So, you ask in your first post to some advices in order to avoid major mistakes. Following the sequences in this thread is more than clear for me that you are going to waste time and money.

What is your problem with your 10 years old system? The answer can be a good start to find out a new setup.

Lets try memory first. Type in Konqueror :

$ vmstat -s

What do you see there?