VirtualBox client CentOS can’t boot up with error message:

1. [FAILED] Failed to start Virtual Machine and Container Registration Service.
2. [FAILED] Failed to start Login Service.
   

Solution

Disable SELINUX config with the following steps during boot up sequence:

1. During Grub boot up stage, press 'e' to edit grub sequence;
2. Add systemd.unit=rescue.target to the end of line with linux16 and boot with rescue mode;
3. Press ctrl+x to continue boot sequence

Config

• CentOS 7 3.10
• VirtualBox 6.0.10

Tricks

• The cause of this boot up issue was difficult to found and the original setting of SELINUX was ‘permissive’ not ‘enabled’. However, this issue may also be owing to bugs in VirtualBox 6.
• During boot up process, by default the boot up is quiet, i.e. no system message will be displayed, only the boot up progress bar is seen. However, pressing Esc key will let you see the detail boot up messages.

The post CentOS VM Client Can’t Boot Up appeared first on LarryLai.

OpenSUSE suddenly could not boot to GUI mode, but being kicked out to recovery mode with the CLI mode with the warning of something like no space to write on device, and the hard disk activity light was unexpectedly always on.

Solution:

• At the recovery mode, login as root and delete some snapshots.
• Execute “snapper ls” to get the snapshot numbers
• Execute “snapper delete [start number] – [end number]”
• Reboot

Tricks:

1. This issue probably occurs only on linux system with btrfs partition in which snapshots are automatically generated. Thus, it should be paid extra care to decide whether to use traditional ext3 or ext4 instead of the default partition option: btrfs suggested by OpenSUSE during installation.
2. When typing “df -h”, the storage usage seems to be normal. No storage or any partition full could be noticed.
3. When hard disk activity light always on, it seems that something related to hardware is wrong but actually it doesn’t.
4. My partition config. fully agreed OpenSUSE suggestion that btrfs for / directory and xfs for /home directory. Yesterday, due to some video files transfer from desktop PC to iPhone using FTP, I setup FTP server on desktop using proftpd, the default directory on server side is /srv/ftp. Probably the new video files are so large that btrfs generated large snapshots under / directory.

Config:

• OpenSUSE 13.2
• KDE4 1.0

The post OpenSUSE Boot Up Issue appeared first on LarryLai.

Suddenly found that the Serif fonts appeared in Linux is uglier than those appeared on Mac OS X.

Solution:

Configure Desktop by enabling Use sub-pixel rendering, and choose Slight in Hinting style.

Config:

• OpenSuse 13.1
• KDE 4.11

Tricks:

Some suggestion was to install Microsoft fonts, actually this could be done but still ugly Serif fonts was shown.

The post Ugly Font Appearance in Linux appeared first on LarryLai.

Installed Linux driver for Brother DCP-L2540DW printer driver, then found out that printing for one page or double-sided page is fine, but it always shows error

“ERROR NAME; memoryfull” printed on a page then stop.

when starting to print multiple pages from a file. Not working even tune down the resolution from 600dpi to 300dpi as suggested by Brother’s official support site.

Solution:

Replace driver:

Brother DCP-L2540DW with driver Brother DCP-8045D BR-Script3

by:

Brother DCP-8045D – CUPS+Gutenprint v5.2.9

Tricks:

After installing the rpm package downloaded from Brother’s official support site, there is no driver with name specific for DCP-L2540DW, thus installing 8045D instead.

Config:

• Brother Monochrome Laser Printer DCP-L2540DW
• OpenSUSE 13.1-13.6.1
• CUPS ver. 1.5.4-12.13.1

The post Laser Printer for Linux appeared first on LarryLai.

OS unbootable and show the following message:

Kernel panic – not syncing: VFS: Unable to mount root fs on unknown-block(0,0)

Solution:

• At waiting to boot loader
• click any key to access the boot kernel menu
• Select previous kernel version other than the default latest installed one

Config:

• CentOS    6.4
• Kernel      2.6.32-431.1.2.0.1.el6.x86_64

Tricks:

Upon upgrading the kernel or installed the kernel-devel packages, the system was still running the current kernel until next system reboot. In case, the reboot schedule was long after this kernel-devel, it is not easy to remember kernel-devel was installed and as a side effect also upgraded the kernel.

The post CentOS Not Bootable after Install Kernel-devel rpm appeared first on LarryLai.

Using SCIM happily to input Chinese characters with my previous Linux distribution – Ubuntu, but using SCIM in my current OpenSuse is painful as the screen refeashing always crawls after selecting a chinese character, sometimes like system hangs.

Solution:

1. Uninstall SCIM
2. Install fcitx packages
3. Add Secondary Language from Yast to include Traditional Chinese such that appropriate fonts are to be installed.

Configuration:

• OpenSuse     12.3 (x86_64)
• fcitx               4.2.7

The post OpenSuse Chinese Input Issue with SCIM appeared first on LarryLai.

Worked with UNetbootin to make bootable USB to install new OS or rescue OS several times happily, but didn’t work anymore for OpenSuse. UNetbootin silently could not successfully Extracting and Copying Files (i.e. Step 2).

Solution:

Use MagicDisc to mount the OpenSuse ISO file

Copy the content of the ISO to a temp directory

Use All FreeISO Creator to create ISO

Config:

• Windows 7
• UNetbootin583
• MagicDisc 2.7 build 106
• All FreeISO Creator 3.1.9

Tricks:

Seems that funny to extract the ISO and wrap it again, but found no other way to make the bootable USB.

The post Bootable USB with UNetbootin appeared first on LarryLai.

System hang, then reboot but unable to boot up!

system suggested “e2fsck”. after fixing/ cleaning some files, “unable to set superblock flags” on /user/local

Solution:

• execute: e2fsck -b 32768 /dev/hda2
• reboot

Tricks:

• system suggested: e2fsck -b 8136 <device>
• can’t run this command as 8136 is not a good magic no.
• visit: http://ge.ubuntuforums.com/showthread.php?p=5060346

The post unable to set superblock flags appeared first on LarryLai.

Run:

Yum install postgreSQL

for SQL-Ledger, but appear:

unable to find pid

then the shell running yum as root quited unexpectedly

Solution:

Run:

rpm –rebuilddb; yum clean all

Tricks:

After the weird behaviour of yum being quited unexpectedly, there are 0 Highmem, 0 free page messages in /var/log/messages, but it finally seems that there is nothing wrong with the memory management. The reason why rpm db corrupt may be due to interruption of a running yum process.

Configuration:

• HW: Dell SC1425 w/ Xeon 2.8GHz x1, 512MB x2 memory
• OS: CentOS 3.4

The post yum quited unexpectedly appeared first on LarryLai.

install application for scanning images in Linux

Solution:

install sane-backends, xsane,

Tricks:

also install xsane-gimp if having xsane as a plugin of gimp (instead of ln -s /usr/bin/xsane ~/.gimp*/plug-ins this DOESN’T work!!!)
if connecting more than 1 scanner device, or having video card installed
run:

xsane [backendname:device]

to start xsane with corrent device without trouble of choosing device immediately after startup of xsane.

backendname:device can be obtained by:

scanimage -L

The post Using Scanner appeared first on LarryLai.