Posts tagged performance

Making Emacs Startup Faster

By Eric Z Ma,
I use Emacs in terminals and start/close Emacs frequently as needed like in a file checking-editing-closing loop. However, Emacs seems take some time to start up especially some heavy modes are used. How to make Emacs start up faster? (If you just want the solution/script first, find the command in the summary section.) My solution is to make use of the server/client feature of Emacs ∞ This is how it works. » Read more

Xen DomU’s I/O Performance of LVM and loopback Backed VBDs

By Eric Z Ma,
This posts list benchmark (using bonnie++) result of I/O performance of Xen LVM and loopback backed VBDs. The configuration of machines Dom0 VCPU: 2 (Intel(R) Xeon(R) CPU E5520  @ 2.27GHz) Memory: 2GB Xen and Linux kernel: Xen 3.4.3 with Xenified 2.6.32.13 kernel DomU VCPU: 2 Memory: 2GB Linux kernel: Fedora (2.6.32.19-163.fc12.x86_64) DomU’s profile: name=”10.0.1.200″ vcps=2 memory=2048 disk = [‘phy:vg_xen/vm-10.0.1.150/vmdisk0,xvda,w’] #disk = [‘tap:aio:/lhome/xen/vm0-f12/vmdisk0,xvda,w’] #disk = [‘file:/lhome/xen/vm0-f12/vmdisk0,xvda,w’] vif=[‘bridge=eth0′] bootloader=”/usr/bin/pygrub” #extra=”single” on_reboot=’restart’ on_crash=’restart’ The “disk” lines is changed depending on the driver used. » Read more

Xen Solutions

By Eric Z Ma,
The Xen solutions including installing and configuring Dom0 and DomU are summarized here. This post will be updated when our solution changes. Only the latest tested stable solutions are listed here. 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. » Read more

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

By Eric Z Ma,
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

A Simple CPU and Memory Performance Test of Xen Dom0 and DomU

By Eric Z Ma,
Please refer to Setting Up Xen Dom0 on Fedora : Xen 3.4.1 with Linux Kernel 2.6.29 on Fedora 12 for the platform of this test (this test runs on Fedora 11, however). I have done some simple performance test on DomU and Dom0 and compare with the performance on physical machines. These test are simple, but it can provides some performance factor of xen. » Read more