Tag Archive for linux

Linux Desktop experiences


A long-long years ago (til 2007) I used linux as desktop (Gentoo exactly).

After, the windows 7 and the 10 also will be a very-very good PC OSs.

BUT I tried the Ubuntu 20.04, and it seems work wine from 1 month at my 2in1 PC with WWAN card (DELL 7390).

I would like to collect some useful programs which I found very userful, fast and maintined (actually).

Program typeLinux programWindows alternative
(what I liked to use)
Screenshot maker and editorFlameshotGreenshot
Clipboard managerCopyQDitto
File managerDouble CommanderTotal Commander
SSH session managerRemminaKitty
VNC session managerRemminaUltraVNC
RDP session managerRemminaRDCman (discontinued)

mdadm raid 5 all disk became spare

After an irregular restart, the raid 5 array became unreachable. D’oh!

# cat /proc/mdstat

$ cat /proc/mdstat 
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] 
md3 : inactive sdd3[3](S) sde3[4](S) sdf3[6](S) sdg3[5](S)
      6546850144 blocks super 1.2

As you can see all sd[cdefg]2 partitions are (S)pare.

First, we had to stop the array:

# mdadm --stop /dev/md3

and after we have to reassamle the array:

# mdadm --assemble /dev/md3 /dev/sdc3 /dev/sdd3 /dev/sde3 /dev/sdf3 /dev/sdg3 --verbose

After, we have to see like this:

$ mdadm --assemble /dev/md3 /dev/sdc3 /dev/sdd3 /dev/sde3 /dev/sdf3 /dev/sdg3 --verbose
mdadm: looking for devices for /dev/md3
mdadm: Fail create md3 when using /sys/module/md_mod/parameters/new_array
mdadm: /dev/sdc3 is identified as a member of /dev/md3, slot 0.
mdadm: /dev/sdd3 is identified as a member of /dev/md3, slot 2.
mdadm: /dev/sde3 is identified as a member of /dev/md3, slot 3.
mdadm: /dev/sdf3 is identified as a member of /dev/md3, slot -1.
mdadm: /dev/sdg3 is identified as a member of /dev/md3, slot 1.
mdadm: added /dev/sdg3 to /dev/md3 as 1
mdadm: added /dev/sdd3 to /dev/md3 as 2
mdadm: added /dev/sde3 to /dev/md3 as 3
mdadm: added /dev/sdf3 to /dev/md3 as -1
mdadm: added /dev/sdc3 to /dev/md3 as 0
mdadm: /dev/md3 has been started with 4 drives and 1 spare.

cool part of it:

mdadm: /dev/md3 has been started with 4 drives and 1 spare.

let’s check the result:

$ cat /proc/mdstat 
Personalities : [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] 
md3 : active raid5 sdc3[0] sdf3[6](S) sde3[4] sdd3[3] sdg3[5]
      4910137344 blocks super 1.2 level 5, 512k chunk, algorithm 2 [4/4] [UUUU]
      bitmap: 0/13 pages [0KB], 65536KB chunk

And it done, huh 🙂

IDEA linux – import module hanging

I tried IDEA on linux. OF course, It started with gooling 😀

I tried to import the modules, but hanged… (on a freshly created project, with import maven modules)


The resolution was:

File -> invalidate caches and restart

src: https://stackoverflow.com/questions/47626478/intellij-idea-stucked-on-loading-project-screen

Transmission network problem

Recently started in debug mode on Transmission and I see:

[17:42:40.319] UDP Failed to set receive buffer: requested 4194304, got 262142 (tr-udp.c:75)
[17:42:40.319] UDP Please add the line "net.core.rmem_max = 4194304" to /etc/sysctl.conf (tr-udp.c:80)
[17:42:40.319] UDP Failed to set send buffer: requested 1048576, got 262142 (tr-udp.c:86)
[17:42:40.319] UDP Please add the line "net.core.wmem_max = 1048576" to /etc/sysctl.conf (tr-udp.c:91)

By tuning the two variables, higher throughput can be achieved more easily using uTP.

Here’s the relevant part from the changeset :

Since we are using a single UDP socket to implement multiple UTP sockets,
and since we are not always timely in servicing an incoming UDP packet,
it is important to use a large receive buffer. The send buffer is probably
less critical, we increase it nonetheless.

Four megabytes might seem huge for embedded clients, but running behind a dedicated connection, it might even become too small. I recommend using 16 megabytes for receive buffering and 4 for the send buffer. That is, because uTP implements a retransmission algorithm and by scaling up the buffers we can achieve fewer retransmits because of dropped datagrams. Let’s set it up that way.

Check actual settings:

sysctl -p

do the modifications:

echo 'net.core.rmem_max = 16777216' >> /etc/sysctl.conf
echo 'net.core.wmem_max = 4194304' >> /etc/sysctl.conf
sysctl -p

src: https://falkhusemann.de/blog/2012/07/transmission-utp-and-udp-buffer-optimizations/

Debian 8 Docker daemon default start params remove

Somebody at debian’s thought, it will be very usefull, if adds the

-H fd://

param to the docker daemon default

To remove it, and use the /etc/docker/daemon.json do this below:

vi /lib/systemd/system/docker.service

mod this line:

ExecStart=/usr/bin/dockerd -H fd://



than reload the daemon config

systemctl daemon-reload

and reload the service

/etc/init.d/docker restart



gigabit e1000e Detected Hardware Unit Hang

If we see it in

$ dmesg
[Tue Feb 13 20:53:07 2018] e1000e 0000:00:19.0 eno1: Detected Hardware Unit Hang:
                             TDH                  <1b>
                             TDT                  <76>
                             next_to_use          <76>
                             next_to_clean        <1b>
                             time_stamp           <361c0382c>
                             next_to_watch        <1e>
                             jiffies              <361c056ec>
                             next_to_watch.status <0>
                           MAC Status             <80083>
                           PHY Status             <796d>
                           PHY 1000BASE-T Status  <3800>
                           PHY Extended Status    <3000>
                           PCI Status             <10>
[Tue Feb 13 20:53:07 2018] e1000e 0000:00:19.0 eno1: Reset adapter unexpectedly

the resulution is:

$ ethtool -K eth0 gso off gro off tso off


for gentoo, add these lines into

$ vi /etc/conf.d/net

  /usr/sbin/ethtool -K eno1 gso off gro off tso off



src: https://serverfault.com/questions/616485/e1000e-reset-adapter-unexpectedly-detected-hardware-unit-hang

Adot napnál régebbi fájlok megkeresése

find . -maxdepth 1 -daystart -mtime +0 -ls


Cert lementése remote szerverről linuxon

echo -n | openssl s_client -connect HOST:PORTNUMBER | sed -ne '/-BEGIN CERTIFICATE-/,/-END CERTIFICATE-/p' > /tmp/$SERVERNAME.cert


Keresés tar archivumok fájljain belül

zgrep -a "keresett_string" 12*/audit.log.*.gz

vagy így is megeszi

zgrep -a keresett_string 12*/audit.log.*.gz


AVI fájlok merge

Csudi-mudi jó kis parancs, csak mindig elfelejtem 🙂

avimerge -o cd.avi -i cd1.avi cd2.avi