Fanta's questions

Since I configured two SATA SSDs as a RAID0 with lvm2, Disks (gnome-disk-utility) reports in its benchmark that their reading speed is around doubled, but their writing speed is halved. Screenshots attached. Is it as expected? Or how can I troubleshoot/fix that?

The two SSDs are a Samsung 840 EVO and a Samsung 850 EVO. Running Ubuntu 22.04.1

-> sudo pvscan
  PV /dev/sda   VG sata_ssds       lvm2 [232,88 GiB / 0    free]
  PV /dev/sdb   VG sata_ssds       lvm2 [232,88 GiB / 0    free]
  Total: 2 [<465,77 GiB] / in use: 2 [<465,77 GiB] / in no VG: 0 [0   ]
-> sudo lvs --segments
  LV    VG        Attr       #Str Type    SSize   
  raid0 sata_ssds -wi-a-----    2 striped <465,77g
-> sudo lvs -a -o name,copy_percent,devices sata_ssds
  LV    Cpy%Sync Devices                
  raid0          /dev/sda(0),/dev/sdb(0)
-> udisksctl  status
MODEL                     REVISION  SERIAL               DEVICE
--------------------------------------------------------------------------
Samsung SSD 980 PRO 500GB 5B2QGXA7  S5GYNX0T708561R      nvme0n1 
Samsung SSD 980 PRO 500GB 5B2QGXA7  S5GYNX0T708613K      nvme1n1 
Samsung SSD 840 EVO 250GB EXT0BB6Q  S1DBNSBF835020A      sda     
Samsung SSD 850 EVO 250GB EMT02B6Q  S21PNXAG665086W      sdb     
TOSHIBA HDWD120           MX4OACF0  58QZRRGCS            sdc     
JMicron Tech              0209      DD564198838AA        sdd     
Generic MassStorageClass  1536      000000001536         sde     
Generic MassStorageClass  1536      000000001536         sdf     

Before RAID0

With RAID0

I have installed Focal (dual boot, Windows 10 was already installed), and the GRUB menu lists only Ubuntu, no Windows, which was customary on my PC also with previous Ubuntu releases. With previous releases, however, running boot-repair would fix the issue, but not this time.

Oddly enough, when I see the GRUB menu if I:

• hit [Esc] to enter the GRUB CLI
• type exit to leave the GRUB CLI

then the system boots straight into Windows 10.

I have also run sudo grub-update but no change.

Under Windows 10, I have run bcdedit /set {bootmgr} path \EFI\ubuntu\shimx64.efi but no change. I noticed that under C:\Windows\Boot\EFI there is no ubuntu directory, and can't find a shimx64.efi in there.

In the motherboard UEFI I can choose two other entries to boot from, but one behaves the same, and the other boots straight into Windows 10, with no GRUB menu.

This is a pastebin with the report from boot-repair https://paste.ubuntu.com/p/6ZHvQqSfMN/

Here below the /etc/default/grub

Any other information I can collect to troubleshoot the issue?

# If you change this file, run 'update-grub' afterwards to update
# /boot/grub/grub.cfg.
# For full documentation of the options in this file, see:
#   info -f grub -n 'Simple configuration'

GRUB_DEFAULT=0
GRUB_TIMEOUT_STYLE=menu
GRUB_TIMEOUT=10
GRUB_DISTRIBUTOR=`lsb_release -i -s 2> /dev/null || echo Debian`
GRUB_CMDLINE_LINUX_DEFAULT="quiet splash"
GRUB_CMDLINE_LINUX=""

# Uncomment to enable BadRAM filtering, modify to suit your needs
# This works with Linux (no patch required) and with any kernel that obtains
# the memory map information from GRUB (GNU Mach, kernel of FreeBSD ...)
#GRUB_BADRAM="0x01234567,0xfefefefe,0x89abcdef,0xefefefef"

# Uncomment to disable graphical terminal (grub-pc only)
#GRUB_TERMINAL=console

# The resolution used on graphical terminal
# note that you can use only modes which your graphic card supports via VBE
# you can see them in real GRUB with the command `vbeinfo'
#GRUB_GFXMODE=640x480

# Uncomment if you don't want GRUB to pass "root=UUID=xxx" parameter to Linux
#GRUB_DISABLE_LINUX_UUID=true

# Uncomment to disable generation of recovery mode menu entries
#GRUB_DISABLE_RECOVERY="true"

# Uncomment to get a beep at grub start
#GRUB_INIT_TUNE="480 440 1"

[Additional info] I have two SSDs configured as RAID 0 with Intel RST. On that RAID, I have both Windows 10 and Ubuntu 20.04. See pic below. In the UEFI BIOS, Sata mode selection is set to RAID, no AHCI.

After removing the boot entry as per oldfred recommendation (with efibootmgr), the PC booted directly into Windows 10, without showing the GRUB menu anymore. From there, I modified the boot entries again to regain access to Ubuntu; I also tried running boot-repair one more time, this is the current status:

$ sudo efibootmgr -v
BootCurrent: 000E
Timeout: 1 seconds
BootOrder: 000E,0000,0007,0004,0009,0001
Boot0000* Windows Boot Manager  HD(2,GPT,baeb537c-b470-48ab-ae4c-4663a62e8d2a,0x109000,0x32000)/File(\EFI\ubuntu\shimx64.efi)WINDOWS.........x...B.C.D.O.B.J.E.C.T.=.{.9.d.e.a.8.6.2.c.-.5.c.d.d.-.4.e.7.0.-.a.c.c.1.-.f.3.2.b.3.4.4.d.4.7.9.5.}...,................
Boot0001* CD/DVD Drive  BBS(CDROM,,0x0)AMGOAMNO........o.H.L.-.D.T.-.S.T. .D.V.D.R.A.M. .G.H.2.2.N.S.7.0....................A...........................>..Gd-.;.A..MQ..L.2.K.B.Z.9.8.5.8.2.5. .9. . . . . . . . ......AMBO
Boot0004* ST31000524AS  BBS(HD,,0x0)AMGOAMNO........m.A.0.S.0. .T.O.S.H.I.B.A. .H.D.W.D.1.2.0.........................rN.D+..,.\...........>..Gd-.;.A..MQ..L.A.0.S.0. .T.O.S.H.I.B.A. .H.D.W.D.1.2.0......AMBOAMNO........g.A.0.S.1. .S.T.3.1.0.0.0.5.2.4.A.S.........................rN.D+..,.\...........8..Gd-.;.A..MQ..L.A.0.S.1. .S.T.3.1.0.0.0.5.2.4.A.S......AMBOAMNO........_.I.n.t.e.l. .V.o.l.u.m.e.0.........................rN.D+..,.\...........0..Gd-.;.A..MQ..L.I.n.t.e.l. .V.o.l.u.m.e.0......AMBO
Boot0007* Windows Boot Manager  HD(2,GPT,baeb537c-b470-48ab-ae4c-4663a62e8d2a,0x109000,0x32000)/File(\EFI\Microsoft\Boot\bootmgfw.efi)
Boot0009* Removable Drive   BBS(Floppy,,0x0)AMGOAMNO..........G.e.n.e.r.i.c. .M.a.s.s.S.t.o.r.a.g.e.C.l.a.s.s.1.5.3.6....................A.....................................N..Gd-.;.A..MQ..L.G.e.n.e.r.i.c. .M.a.s.s.S.t.o.r.a.g.e.C.l.a.s.s.1.5.3.6......AMBOAMNO..........G.e.n.e.r.i.c. .M.a.s.s.S.t.o.r.a.g.e.C.l.a.s.s.1.5.3.6....................A.............................N..Gd-.;.A..MQ..L.G.e.n.e.r.i.c. .M.a.s.s.S.t.o.r.a.g.e.C.l.a.s.s.1.5.3.6......AMBO
Boot000E* ubuntu    HD(2,GPT,baeb537c-b470-48ab-ae4c-4663a62e8d2a,0x109000,0x32000)/File(EFI\Ubuntu\grubx64.efi)

I have installed the Dolphin file manager under Ubuntu 18.04/Gnome (with apt install). It doesn't show thumbnails for any file, neither in the folder nor in the information panel (to the right). See screenshot. How can I fix it?

Also, in the Dolphin Preferences I noticed that under General > Previews > Show previews for: there is a blank list, which I am not allowed to edit. I believe I should have a list of file types there. See screenshot.

I have tried deleting the content of ~/.cache/icon-cache.kcache and ~/.cache/thumbnails.tar, then logging out and in again, but no change.

I also tried the fix that should address video clip thumbnails, but got an error in the process:

-> sudo apt install ffmpegthumbs mplayerthumbs kffmpegthumbnailer
[sudo] password for fanta: 
Reading package lists... Done
Building dependency tree       
Reading state information... Done
Package mplayerthumbs is not available, but is referred to by another package.
This may mean that the package is missing, has been obsoleted, or
is only available from another source

E: Package 'mplayerthumbs' has no installation candidate

Note the issue is not limited to thumbnails of video clips, it applies to all files, including images (Jpeg, PNG, etc.).

Update: I have tried adding the KDE Plasma repository

deb http://archive.neon.kde.org/user bionic main

then run a sudo apt upgrade and re-booted. I didn't actually install KDE Plasma. Now the thumbnails are working, but I am getting other malfunctions, including the Software & Updates app that doesn't start (software-properties-gtk issues "aptsources.distro.NoDistroTemplateException: Error: could not find a distribution template for neon/bionic"). Therefore I am undoing the changes.

After a dual-boot Windows 10/Ubuntu 18.04 installation, it looked like the PC was booting straight to Ubuntu, without showing the GRUB menu, after a short pause. I had already run Boot Repair under Ubuntu and checked bcdedit under Windows.

It turned out, during boot I had to hit the Esc key when the screen turned Ubuntu-purple, in order to display the GRUB menu and be allowed to choose the OS to boot. Not pressing Esc, after a time-out, the PC would boot to the default (Ubuntu).

I don't want to have to hit Esc every time during boot: how can I have the boot process show the GRUB menu right away, with no need for me to hit Esc?

When I pin a certain application (CLion) to the task manager, and click on the icon, the application fails to start because the icon refers to an incorrect path.

How do I edit that path, such that clicking on the icon starts the application?

I have looked into plasma-org.kde.plasma.desktop-appletsrc, but cannot find the path in there. With gnome that information is under /home/fanta/.local/share/applications, but KDE seems to ignore that directory.

Also note that unpinning the application, and then pinning it again, doesn't help.

I am using KDE Plasma V 5.12.7, KDE Frameworks V 5.44.0, Ubuntu 18.04.

After I start an application from the task bar, the corresponding icon remains highlighted, with a dim, gray, vertical bar, which is barely visible. How can I change the color of that bar?

In System Settings > Colors I found how to customize it when it is selected or hovered (under "Common Colors", "Focus Decoration" and "Hover Decoration"). But how about when the icon is neither selected nor hovered? I would like to customize the color of the highlight (vertical bar) indicated in the screenshot below.

I am using KDE Plasma V 5.12.7, KDE Frameworks V 5.44.0, with the Breeze desktop theme.

Where can I read the hex or RGB codes for colors used by the gnome-terminal?

Under the terminal Preferences, I see it is using colors from the system theme, but I don't know where to read those. The system theme should be what as installed by default with Ubuntu 18.04.

I understand themes are under /usr/share/themes; but I can't figure out which is the CSS file and the code within it I should be looking at.

After installing the Evolution and Geary e-mail clients, Ubuntu desktop and application GUIs are messed up. See screenshot below for an example; as you can see, tabs are not separated anymore, and buttons (Revert, Close) are not drawn.

How can I restore the previous desktop/GUI appearance, without re-installing Ubuntu?

Things I have tried:

• purge Evolution and Geary
• purge and reinstall ubuntu-desktop (from console, CTRL+ALT+F1)
• purge and reinstall unity (from console, CTRL+ALT+F1)
• rm -rf ~/.compiz-1 ~/.config/compiz-1

Running Ubuntu 16.04 with its default desktop.