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…
BIOS: Basic Input Output Systems UEFI: Unified Extensible Firmware Interface UEFI is the advanced BIOS, which solves some limitations in BIOS such as 1, 16-bit processor mode; 2, 1 MB addressable space and PC AT hardware. References: https://en.wikipedia.org/wiki/Unified_Extensible_Firmware_Interface
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…
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…
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…
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.
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…
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…
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…
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…
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…
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…
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…
In Linux, it is often necessary to check the firmware version of your system. The firmware, also known as BIOS (Basic Input/Output System), is a software that is built into the hardware of your system and serves as an interface between the hardware and the operating system. In this post, we will explore how to…
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…
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 =…