Shrinking an Ext4 File System on LVM in Linux

In Extending a Mounted Ext4 File System on LVM in Linux, we introduced how to extend a mounted ext4 filesystem on LVM Logical volume by adding a new physical volume. It is also common to shrink an ext4 file system as to spare some disk space. In this post, I will discuss how to shrink an ext file system on a LVM logical volume (LV). » Read more

Configuring Linux Kernel Video Mode for 32-bit and 16-bit Boot Protocols

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 protocolFor machine with some new BIOS other than legacy BIOS, such as EFI, LinuxBIOS, etc, and kexec, the 16-bit real mode setup code in kernel based on legacy BIOS can not be used, so a 32-bit boot protocol needs to be defined. » Read more

Extending a Mounted Ext4 File System on LVM in Linux

LVM is a great tool to manage hard disks on Linux—you can abstract the hard drives away and manage logical volumes from volume groups, you can dynamically add or remove hard drives while the file systems on the logical volumes need not to backed up and recovered, and you may create many snapshots of the logical volumes as you like. In this post, I will introduce how to extend a mounted ext4 file system on a LVM logical volume on Linux. » Read more

Installing Fedora 17 PV Domain-U on Xen with PXE Booting

An introduction to the general method of installing Domain-U on Xen is introduced here: Setting Up Stable Xen DomU with Fedora: Unmodified Fedora 12 on top of Xenified Fedora 12 Dom0 with Xen (this is a general introduction, some details are changed, such as ‘xl’ replacing ‘xm’, LVM backing the disk for higher performance. But the general process is the same). » Read more

Extending a LVM Volume Group

We introduced how to create a LVM group with two hard disk partitions, which the LVM group can be used for installing LVM backed Xen DomUs. The LVM volume can have large capacity from several hard disks. However, we may use all the disk space after some time and we may need to extend the capacity. In this post, we introduce how to extend a LVM group with a new hard disk. » Read more

Xen with LVM

LVM volumes as backing for DomU’s file system is an appealing solution to Xen VBD. LVM volumes can dynamically grow/shrink and snapshot. These features make it simple and fast to duplicate DomU and adding storage to DomU. This post is a summary of tutorials related Xen DomU and LVM. Setting Up LVM Backed Xen DomU Duplicating LVM Backed Xen DomU Duplicating and Backing Up LVM Backed Xen DomU from a Remote Server » Read more

Setting Up LVM Backed Xen DomU

LVM volumes as backing for DomU’s file system is an appealing solution to Xen VBD. LVM volumes can dynamically grow/shrink and snapshot. These features make it simple and fast to duplicate DomU and adding storage to DomU. Creating LVM-backed Xen DomU is introduced in this post. Create LVM-backed VBD Suppose we have a LVM volume group for Xen now: vg_xen. » Read more

Duplicating LVM Backed Xen DomU

LVM’s snapshot feature enables us to duplicate an LVM backed Xen DomU in seconds rather than minutes. We no longer need to copy the entire file system image like backing up file backed Xen DomU. We just need to make a snapshot of the current Xen DomU in seconds. When there are changes to the file system of the new DomU, LVM will make a copy of the physical block of the logical volume write the the new volume. » Read more

Setting Up Xen DomU on Fedora Linux (Fedora 12)

Creating file-backed virtual block device (VBD) for Xen virtual machines and installing Fedora 12 in Xen DomU via internet will be introduced. Note that this tutorial is based on a pretty old OS (Fedora 12). But the method here is still valid while some minor details may need to be changed for latest Xen and Linux such as such as ‘xl’ replacing ‘xm’, LVM backing the disk for higher performance. » Read more

An I/O Performance Comparison Between loopback Backed and blktap Backed Xen File-backed VBD

I 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 bench comparison. Note: if your VM is I/O intensive, you may consider setting up LVM backed DomU. » Read more

Installing NVIDIA Driver in Fedora

Using rpmfusion’s rpm packages to install NVIDIA driver in Fedora is introduced in this post. First, check the proper drivers for the card on [1]. 1. Add rpmfusion. Enable RPM Fusion repositories 2. Install the driver # yum install kmod-nvidia xorg-x11-drv-nvidia The reboot system. 3. Edit /etc/X11/xorg.conf # nvidia-xconfig The nouveau module conflicts with the nvidia module. But rpmfusion’s packages has already add it to blacklist. » Read more