5 Tips To Speed Up Linux Software Raid Rebuilding And Re-syncing

Posted on in Categories Data recovery, Hardware, Linux, Storage last updated May 1, 2017

It is no secret that I am a pretty big fan of excellent Linux Software RAID. Creating, assembling and rebuilding small array is fine. But, things started to get nasty when you try to rebuild or re-sync large size array. You may get frustrated when you see it is going to take 22 hours to rebuild the array. You can always increase the speed of Linux Software RAID 0/1/5/6 reconstruction using the following five tips.

Vmware Linux Guest Add a New Hard Disk Without Rebooting Guest

Posted on in Categories CentOS, fedora linux, Hardware, Howto, Linux, Linux desktop, Linux distribution, Linux Virtualization, RedHat/Fedora Linux, Storage, Sys admin, Tips, vmware last updated July 18, 2009

As a system admin, I need to use additional hard drives for to provide more storage space or to separate system data from user data. This procedure, adding physical block devices to virtualized guests, describes how to add a hard drive on the host to a virtualized guest using VMWare software running Linux as guest.

It is possible to add or remove a SCSI device explicitly, or to re-scan an entire SCSI bus without rebooting a running Linux VM guest. This how to is tested under Vmware Server and Vmware Workstation v6.0 (but should work with older version too). All instructions are tested on RHEL, Fedora, CentOS and Ubuntu Linux guest / hosts operating systems.

Software Vs Hardware RAID

Posted on in Categories Hardware, Linux, Storage, Tips, UNIX, Windows server last updated July 7, 2009

A redundant array of inexpensive disks (RAID) allows high levels of storage reliability. RAID is not a backup solution. It is used to improve disk I/O (performance) and reliability of your server or workstation. A RAID can be deployed using both software and hardware. But the real question is whether you should use a hardware RAID solution or a software RAID solution.

Increase Your VMware Virtual Hard Disk Size ( vmdk file )

Posted on in Categories Backup, Hardware, Howto, Linux desktop, Linux Virtualization, Storage, Sys admin, Tips, Ubuntu Linux, vmware, windows vista last updated June 9, 2009

I’ve Windows Vista installed as a guest under Ubuntu Linux using VMWARE Workstation 6.0. This is done for testing purpose and browsing a few site that only works with Internet Explorer. Since I only use it for testing I made 16GB for Vista and 5GB for CentOS and 5GB in size for FreeBSD guest operating systems. However, after some time I realized I’m running out of disk space under both CentOS and Vista. Adding a second hard drive under CentOS solved my problem as LVM was already in use. Unfortunately, I needed to double 32GB space without creating a new D: drive under Windows Vista. Here is a simple procedure to increase your Virtual machine’s disk capacity by resizing vmware vmdk file.

Poll: Common Causes Of Downtime In Your Data Center

Posted on in Categories Business, data center, Hardware, High performance computing, Linux, Poll, Storage, UNIX last updated May 27, 2009

Unplanned downtime may be the result of a software bug, human error, equipment failure, power failure, and much more. Last week was a bad one. We faced three different downtime:

  • First, there was a fiber cut for one of our data center resulting into routing anomalies due BGP reroute. Traffic was rerouted but updating those BGP tables took some time to update.
  • Someone from networking team failed to follow proper maintenance procedures for network device resulted into 55 minutes downtime.
  • One of our SAN hardware failure – Many internal UNIX / Linux web applications use SAN to store data including file server, tracking apps, R&D apps, IT help desk, LAN and WAN servers failed. This one lasted for 12 hrs. It was stared around midnight. The vendor replaced entire SAN hardware. Now we have dual stacked SAN as a backup device for internal usage.

Note: There is a poll embedded within this post, please visit the site to participate in this post’s poll.

Linux Convert ext3 to ext4 File system

Posted on in Categories CentOS, Data recovery, Linux, Linux desktop, Linux distribution, RedHat/Fedora Linux, Storage, Suse Linux, Sys admin, Tips, Troubleshooting, Tuning, Ubuntu Linux last updated January 23, 2009

Some time ago ext4 was released and available for Linux kernel. ext4 provides some additional benefits and perforce over ext3 file system. You can easily convert ext3 to ext4 file system. The next release of Fedora, 11, will default to the ext4 file system unless serious regressions are seen. In this quick tutorial you will learn about converting ext3 to ext4 file system.

Top 10 Linux Virtualization Software

Posted on in Categories Linux, Linux desktop, Linux distribution, Linux Scalability, Linux Virtualization, Networking, RedHat/Fedora Linux, Security, Solaris, Storage, Ubuntu Linux, UNIX, vmware, Windows server, xen last updated December 31, 2008

Virtualization is the latest buzz word. You may wonder computers are getting cheaper every day, why should I care and why should I use virtualization? Virtualization is a broad term that refers to the abstraction of computer resources such as:

  1. Platform Virtualization
  2. Resource Virtualization
  3. Storage Virtualization
  4. Network Virtualization
  5. Desktop Virtualization

This article describes why you need virtualization and list commonly used FOSS and proprietary Linux virtualization software.

Linux: Boot a 2TB+ partition or Larger Array Using Grub

Posted on in Categories CentOS, data center, fedora linux, File system, Gentoo Linux, Hardware, High performance computing, Howto, kernel, Linux, Linux Scalability, Linux Virtualization, RedHat/Fedora Linux, Storage, Tips, vmware, xen last updated December 4, 2008

I’ve already written about creating a partition size larger than 2TB under Linux using GNU parted command with GPT. In this tutorial, I will provide instructions for booting to a flat 2TB or larger RAID array under Linux using the GRUB boot loader.