Linux Kernel 4.19.70 Release

Posted on

This post summarizes new features, bugfixes and changes in Linux kernel release 4.19.70. Linux 4.19.70 Release contains 95 changes, patches or new features. In total, there are 101,521 lines of Linux source code changed/added in Linux 4.19.70 release compared to Linux 4.19 release. To view the source code of Linux 4.19.70 kernel release online, please
Read more

How to detect whether Linux runs in UEFI or BIOS mode inside the Linux?

Posted on

How to detect whether Linux runs in UEFI or BIOS mode inside the Linux itself without needed to boot the the management console of the mother board? You can detect whether Linux runs in EFI mode by checking whether /sys/firmware/efi exist. In bash, you can test by [ -d /sys/firmware/efi/ ] This technique is used
Read more

How to force a USB 3.0 port to work in USB 2.0 mode in Linux?

Posted on

We know that we can disable USB 3.0 in the BIOS. But is there a way to force a USB 3.0 port to work in USB 2.0 mode inside of a running Linux? On Linux on some platforms booted in BIOS modes, you can use the following command to force USB 2.0 modes for your
Read more

Manage Linux console screen by commands?

Posted on

How to manage Linux console screen by commands? When the screen will be blanked? Put the screen into powerdown mode or power off the screen? 2 tools are useful for managing the console screen on Linux: setterm – set terminal attributes.vbetool – run real-mode video BIOS code to alter hardware state. When the screen will
Read more

How to turn a BIOS-based Linux Mint 17 installation to UEFI booting?

Posted on

I installed Linux Mint 17 in the traditional BIOS mode. However, Windows 8.1 on my computer can only boot in the UEFI mode. I do not want to reinstall the Windows or erase it. How to turn a BIOS-based Linux Mint 17 installation to UEFI booting? You may refer https://help.ubuntu.com/community/UEFIBooting for some information.

How sched_min_granularity_ns, sched_latency_ns and sched_wakeup_granularity_ns in CFS affect the timeslice of processes

Posted on

Abstract Currently, the most famous process scheduling algorithm in Linux Kernel is Completely Fair Scheduling (CFS) algorithm. The core idea of CFS is to let each process share the same proportional CPU resources to run so that it is fair to each process. In this article, I will introduce how sched_min_granularity_ns and sched_latency_ns work internal
Read more

How to Clean RAID Signatures on Linux

Posted on

RAID systems such as MegaRAID add signatures to disks to maintain the infomration on these didks. When we simply remove these disks and install them to another server, Linux on the new server may detect these RAID signature infomration and refuses to continue write to the disk. Here is one example that mkfs reports "apparently
Read more

How to Regenerate Grub2 Config Files on Linux

Posted on

Grub2 config file may need to be re-generated after changing Grub2 configurations such as configuration changes and setting default boot entries. The Grub2’s config file may be at different locations depending on your Linux distro and whether your Linux is booted in BIOS or UEFI mode. This makes regenerating Grub2 config file not easy for
Read more

How to Configure Linux Kernel Video Mode for 32-bit and 16-bit Boot Protocols

Posted on

The Linux kernel has a generic driver for a graphic framebuffer named vesafb on intel boxes. It provides a nice large console for most of modern displays. Setting VESA modes for Linux kernel with 32-bit and 16-bit boot protocol are different. We introduce both methods here. Linux kernel with 32-bit boot protocol For machine with
Read more

How to Set Up RAID0 in MegaRAID BIOS with New Disks

Posted on

The LSI MegaRAID is widely used like in IBM x3620M3 servers. This post introduces the process with screenshots of how to configure the new disks and set up RAID0 in the MegaRAID BIOS for reference by other and myself. It is illustrated with one example by adding a new 2TB hard disk and creating a
Read more

HP Compaq BIOS Crisis Recovery from a Failed BIOS Flashing Using a USB Flash Disk

Posted on

I tried to flash my HP Compaq CQ35-240TX’s BIOS to F.15 but unfortunately failed. The computer turned to white screen. When I restarted (powered off then boot again), this is no response any more: the hard disk and caps lock’s LED keep blinding. I thought "Oh my God! I must send it to HP to
Read more

How to Set Default Entry in Grub2 and Grub

Posted on

Linux booting is usually controlled by Grub or the new Grub2. Setting the default booting entry is a frequent operations. Here, we introduce how to set the default entry in Grub2 and Grub. Setting the default booting entry in grub2 Note1: With some version of grub2, the grub2-set-default method and the script below may not
Read more

How to Find Out the Firmware Version in Linux

Posted on

The firmware version can be easily checked out in Linux by dmidecode, a tool to locate the computer’s Desktop Management Interface (DMI) table and dump the content to human-readable content. The dmidecode can find out more information, but we only used to find out the firmware version here. One command simply: # dmidecode -s bios-version
Read more

Problems during Installing Xen Dom0 in Fedora

Posted on

Here is a list of problem that may occur during installing and configuring Xen Dom0 in Fedora. It is found originally in Fedora systems, but the tips in this post should also be helpful for installing Xen Dom0 on other platforms. BIOS configuration If xen stops at: “I/O virtualization disabled.” We may need to enable
Read more

Creating and Running Virtual Machine Using VMware Player and qemu-img

Posted on

基于VMware Player, qemu-img创建和运行虚拟机 Linux系统上的免费个人虚拟机方案. 1. 创建虚拟硬盘映象文件: qemu-img create -f vmdk WindowsXPPro.vmdk 10G 2. 创建.vmx虚拟机配置文件: 这是一文本文件. WindowsXPPro.vmx内容: config.version = “8” virtualHW.version = “3” ide0:0.present = “TRUE” ide0:0.filename = “WindowsXPPro.vmdk” memsize = “256” MemAllowAutoScaleDown = “FALSE” ide1:0.present = “TRUE” ide1:0.fileName = “auto detect” ide1:0.deviceType = “cdrom-raw” ide1:0.autodetect = “TRUE” floppy0.present = “FALSE” ethernet0.present = “TRUE” usb.present =
Read more