How to debug/check network-related driver information on Linux? Several commands/tools that you may find usefull: Messages: dmesg grep NetworkManager /var/log/messages lshw: list hardware lshw -c network lsusb: list USB devices lsusb rfkill: enabling and disabling wireless devices rfkill unblock all rfkill event iwconfig: configure a wireless network interface iwconfig ifconfig: configure a network interface ifconfig
Tag: Hardware
Windows 7 64-bit fails to install on VirtualBox / Linux with status code 0xc0000225
Posted onWindows 7 64-bit fails to install on VirtualBox on Linux with status code 0xc0000225: “Windows failed to start. A recent hardware or software change might be the cause. To fix the problem: 1. insert your Windows installation disc and restart your computer. 2. Choose your language settings, and click “Next.” 3. Click “Repair your Computer”.
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USB Standards and Supports in Linux
Posted onThe USB standards have evolved to 3.1 and the supported throughput have been increased too. On Linux, the support to USB standards are following the standards development. In this post, we will survey the standards that common hardware support and the support in Linux. USB standards USB 2.0: https://en.wikipedia.org/wiki/USB#USB_2.0 Speed: <= 60MB/s, or 480 Mbps
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How sched_min_granularity_ns, sched_latency_ns and sched_wakeup_granularity_ns in CFS affect the timeslice of processes
Posted onAbstract 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
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How migration thread works inside of Linux Kernel
Posted onAbstract In computer systems, resources have to be balanced so that the performance will be better based on the same hardware. In Linux Kernel system, we will see some migration kernel threads running as daemons to do this kind of jobs as follows. In this article, we will discuss how Linux Kernel balances its hardware/software
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Forcing Linux to Unmount a Filesystem Reporting “device is busy”
Posted onLinux may report “device is busy” when we try to umount a filesystem. This behavior is reasonable as it can help us avoid data loss by disallowing unmouting a filesystem when it is being used. But for situations when we are sure there is something wrong happened or we care not data lost such as
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How to Clean RAID Signatures on Linux
Posted onRAID 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
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How to Find Out Failed Disks’ SATA Ports in Linux
Posted onThe Linux disk names (e.g. sda1, hdb3, etc.) are not reliable—they may be changed if there are hardware changes, such an adding or removing a disk. Additionally, the order for the Linux device names is not always the same as the order of SATA poets. For example, the disk connected to SATA port 0 (first
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How to Bypass Bad fstab Failure When Booting Linux
Posted onIf /etc/fstab file is created with errors or the hardware configuration changes such as adding hard disks, Linux will boot into failure state. We can bypass the fstab failure by adding booting parameters to Linux. We can do this in two methods: Method 1: Boot to single user mode When booting into single user mode,
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Finding Out the Firmware Version in Linux
Posted onIn 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
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Setting up Stable Xen Dom0 with Fedora: Xen 3.4.3 with Xenified Linux Kernel 2.6.32.13 in Fedora 12
Posted onThis is the latest stable and recommended stable Xen Dom0 solution on Fedora 12. No serious bug found till now and we will fix the bugs by ourselves if some appears. It also works on Fedora 14 as well. It should not be hard to use this solution on other versions of Fedora or other
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Problems during Installing Xen Dom0 in Fedora
Posted onHere 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
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How to Set Date, Time and Timezone in Linux
Posted onHow to set date, time and timezone on Linux/Unix box will be introduced in this post. Unix time, or POSIX time which is a system for describing points in time is the number of seconds elapsed since midnight UTC on the morning of January 1, 1970, not counting leap seconds. The number of seconds elapsed
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Setting Up Xen Dom0 on Fedora : Xen 3.4.1 with Linux Kernel 2.6.29 on Fedora 12
Posted onPlease refer to for the latest stable Xen Dom0 solution. In this post, the detailed tutorial for setting up Xen 3.4.1 dom0 on top of Fedora 12 with kernel 2.6.29 will be introduced. Hardware: Dom0 hardware platform: Motherboard: INTEL S5500BC S5500 Quad Core Xeon Server Board CPU: 2 x Intel Quad Core Xeon E5520 2.26G
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An I/O Performance Comparison Between loopback Backed and blktap Backed Xen File-backed VBD
Posted onI have done some I/O performance benchmark test of Xen DomU. For easier management, some of our DomU VMs are using file-backed VBDs. Previously, our VMs are using Loopback-mounted file-backed VBDs. But blktap-based support are recommended by Xen community. Before considering changing from loopback based VBD to blktap based VBD, I have done this performance
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Mostly Used MPlayer Keyboard Control Shortcuts
Posted onMPlayer has a fully configurable, command-driven control layer which allows you to control MPlayer using keyboard. But which are these shortcuts are not immediately know to users of MPlayer. Below is a list of mostly used MPlayer keyboard control shortcuts. They come from the [[man:1|mplayer|mplayer manual]] where you can find a full list of all
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Conferences on Cloud Computing 2013
Posted onThis post lists important conferences related to Cloud Computing in year 2013. SOSP 2013 SOSP’13: The 24th ACM Symposium on Operating Systems Principles. November 3-6, 2013, Nemacolin Woodlands Resort, Pennsylvania. The biennial ACM Symposium on Operating Systems Principles is the world’s premier forum for researchers, developers, programmers, and teachers of computer systems technology. Academic and
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Conferences on Cloud Computing 2012
Posted onThis post lists important conferences on Cloud Computing in year 2012. OSDI 2012 10th USENIX Symposium on Operating Systems Design and Implementation (OSDI ’12) October 8–10, 2012, Hollywood, CA “The tenth OSDI seeks to present innovative, exciting research in computer systems. OSDI brings together professionals from academic and industrial backgrounds in what has become a
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