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Proxmox 2 With Software Raid

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Proxmox Virtual Environment is an easy to use Open Source virtualization platform for running Virtual Appliances and Virtual Machines. Proxmox does not officially support software raid but I have found software raid to be very stable and in some cases have had better luck with it than hardware raid. read more...
permapage | score:8642 | -falko, May 5, 2012

Add Software RAID1 to Ubuntu 11.10 LVM

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This guide explains how to set up software RAID1 on an already running LVM system (Ubuntu 11.10). The GRUB2 bootloader will be configured in such a way that the system will still be able to boot if one of the hard drives fails (no matter which one). read more...
permapage | score:8595 | -falko, March 31, 2012

Set up Network RAID1 with DRBD on Ubuntu 11.10

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This tutorial shows how to set up network RAID1 with the help of DRBD on two Ubuntu 11.10 systems. DRBD stands for Distributed Replicated Block Device and allows you to mirror block devices over a network. This is useful for high-availability setups (like a HA NFS server) because if one node fails, all data is still available from the other node. read more...
permapage | score:8516 | -falko, November 1, 2011

Einarc v1.3: RAID configuration tool

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Most of hard-core Linux admins encountered hardware RAIDs and know what pain they could be to maintain and configure properly. Usually, you have to download some sort of proprietary CLI or GUI tool from vendor's website, learn it, try to understand its commands and, finally, use it to configure RAID or check its status.

Einarc is a solution for all this hassle: it's a universal storage RAID command line interface and an API that provides management for various hardware/software RAID devices. Einarc would autodetect hardware RAID on a server, would automatically downloaded required command-line tool and wrap it around in a convenient and easy to learn syntax. It works as a translator that makes it possible for an admin to control all these devices using simple terms like "physical disc", "logical disc", "adapter", etc., while transparently converting these requests to proprietary RAID paradigms.

For example, no matter what hardware RAID is used on a server, it's always easy to check state of its logical discs with Einarc. Just issue a "logical list" command and grep for "degraded" discs to see if there's a failure. Same thing goes for any event log reading/monitoring (log list), RAID array creation or modification (logical add), setting up various adapter options, etc.

Version 1.3 of Einarc came after massive half a year of work on it and sports the following features:

  • Support for 3ware / AMCC controllers.
  • Full read/write support of Linux software RAIDs.
  • Updated all proprietary utilities URLs, pumped up version numbers, fixed wrapper regular expressions to support new versions of CLIs.
  • Added new calculated fields in adapter_info: PCI product/subproduct and vendor/subvendor IDs. These allow precise identification of PCI devices related to adapters shown by Einarc.
  • Fuller BBU support for Adaptec adapters.
  • Multiple stability and build fixes.

As of version 1.3, the following RAIDs are supported:

  • Adaptec SCSI and SAS/SATA
  • AMCC/3ware
  • Areca
  • LSI MegaRAID SCSI/SAS/SATA
  • Fusion/MPT HBA
  • Linux software MD device (for sake of completeness)

Einarc v1.3 is a part of Inquisitor, a free Linux hardware stress testing and benchmarking platform, which uses Einarc extensively for HDD testing purposes.

read more...
mail this link | permapage | score:8512 | -GreyCat, December 16, 2008

Tutorial: Network RAID1 with DRBD (Debian 6)

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This tutorial shows how to set up network RAID1 with the help of DRBD on two Debian Squeeze systems. DRBD stands for Distributed Replicated Block Device and allows you to mirror block devices over a network. This is useful for high-availability setups (like a HA NFS server) because if one node fails, all data is still available from the other node. read more...
permapage | score:8473 | -falko, August 23, 2011

Tutorial: btrfs RAID1 with Ubuntu 12.10 on a Hetzner Server

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This tutorial shows how to install Ubuntu 12.10 on the btrfs filesystem (with RAID1) on a Hetzner server with two hard drives. While Hetzner's installimage tool doesn't list btrfs as a supported filesystem and only supports software RAID with /dev/md devices, it is still possible to achieve this setup and use the built-in RAID support in btrfs instead of using /dev/md devices. read more...
permapage | score:8427 | -falko, January 7, 2013

Benchmarks: SSD vs. SATA RAID

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Performance differences between SATA RAID and Solid State Drives are measured and discussed...
Solid state drives (SSD) have many advantages over traditional spinning-platter hard drives including no noise, low power and heat generation, good resistance to shock, and most importantly, extremely low seek times. To see just how much an SSD might improve performance, I used Bonnie++ to benchmark a contemporary SSD as it might be used in a laptop computer.
(take a look at these contemporary prints) read more...
mail this link | permapage | score:8413 | -Ray, July 30, 2008 (Updated: April 24, 2012)

Install RAID5 and LVM on Debian

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Do it the easy way with the Debian Etch installer...
Our team at LinuxForce recently put together a Debian server with LVM on a software RAID5 volume. This has been possible through complex installation procedures in the past, but today the Debian Etch installer is capable of handling such an installation if you follow the proper steps, which I outline in this article.

Among other things, we needed the flexibility to write partition tables for Xen on the fly, dependability that would allow a generous replacement window when harddrives failed, and as little possibility of data loss and downtime through harddrive failure as possible.
read more...
mail this link | permapage | score:8214 | -Ray, April 1, 2007

Resize LVM RAID Partitions

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This article describes how you can shrink and grow existing software RAID1 partitions with LVM on top. I have tested this with logical volumes that use ext3 as the file system. I will describe this procedure for an intact RAID array and also a degraded RAID array. read more...
permapage | score:8155 | -falko, January 9, 2009

Tutorial: Set up RAID1 on a remote Linux system vis SSH

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RAID-1 allows to create an exact copy of the original drive. Thus, it results into the increased fault tolerance and easy data recovery option for single server. It is true that the best and easy way to setup a RAID 1 is during installation. But if you forget to setup RAID 1 during installation or if you have added new hard disk after installation, then this how-to covers setting up a RAID-1 mirroring on a running remote Linux system over ssh session. read more...
permapage | score:8151 | -nixcraft, June 21, 2006

Set up RAID1 on running Ubuntu 10.04

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This guide explains how to set up software RAID1 on an already running Ubuntu 10.04 system. The GRUB2 bootloader will be configured in such a way that the system will still be able to boot if one of the hard drives fails (no matter which one). read more...
permapage | score:8130 | -falko, July 6, 2010

Linux Tutorial: Rename a RAID Array

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I am moving a raid array called /dev/md0 from serverA to serverB. On serverB /dev/md0 is already in use. How do I rename a RAID array from /dev/md0 to /dev/md2?

You can move a RAID array (software based RAID array) to another system. However, if /dev/md0 is already is use on serverB, you can rename /dev/md0 as /dev/m2. read more...
permapage | score:8073 | -nixcraft, November 27, 2012

Tutorial: Managing Linux Software RAID

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Setup, monitor and manage software RAID under Linux...
Software RAID is an emulation of what hardware RAID devices do. There are some disadvantages of software RAID compared to hardware RAID: some disk device write performance is lost; there is additional processing burden on the server; and the hot-swappability of disk units is not available. However, the cost of standard disk controllers and devices is much less than those that support RAID modes in hardware. Often a combination of hardware RAID devices and software RAID will provide a flexible and maintainable solution that fits within the availability and budget constraints of the application.
read more...
mail this link | permapage | score:8071 | -Ray, March 15, 2004

Install RAID 10 on Ubuntu

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The Ubuntu Live CD installer does not support software RAID, and the server and alternate CDs only allow you to do RAID levels 0, 1, and 5. Raid 10 is the fastest RAID level that also has good redundancy too. So I was disappointed that Ubuntu did not have it as a option for my new file server. I did not want shell out lots of money for a RAID controller, especially since benchmarks show little performance benefit using a Hardware controller configured for RAID 10 in a file server. read more...
permapage | score:8061 | -falko, August 20, 2008

Installing Ubuntu on a RAID System

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This guide describes how to install Ubuntu (Ubuntu+GNOME) or Kubuntu (Ubuntu+KDE) 6.06.1 LTS (Dapper Drake) on a single or a multi-boot RAID system. It is meant as a variation of Ubuntu Wiki FakeRAID HowTo document, but digested and with minimum commentary. Its goal is to allow new Ubuntu users to complete an entire installation within 30 minutes, almost entirely by copy and paste. read more...
permapage | score:7943 | -falko, February 9, 2007

Booting Linux From a RAID 1 Device

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"...Now that we've got a running system, it's time to tackle that second drive we've put in (the primary drive in the machine). We'll configure it as a RAID device with two drives involved, declaring /dev/hdc to be a mirror of /dev/hda. Here's the really clever part -- we'll declare /dev/hdc as "failed" until we move the operating system off of it and onto the new RAID device. Then simply add /dev/hdc to the RAID as a replacement for the failed disk, and allow it to rebuild..." read more...
permapage | score:7793 | -Ray, January 20, 2001 (Updated: December 13, 2002)

Build your own (very) cheap RAID array

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For a grand total of under $250, a half-terabyte RAID-5 SCSI array...
What self-respecting geek doesn't get the warm fuzzies at the mere mention of the RAID. With the rising GB to Dollar ratio, we felt it was a good time to feature a project that takes Pure Geekieness(TM) and mixes in a good helping of do it your self. Where else are you going to store all those MP3s (legally obtained, of course)? On a single 200 GB Drive? Or a RAID 5 Array? Take you pick, I know where I will be storing mine.
read more...
mail this link | permapage | score:7771 | -Ray, June 27, 2005

Set up RAID1 on CentOS/RedHat 6.0 System

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This tutorial is for turning a single disk CentOS 6 system into a two disk RAID1 system. The GRUB bootloader will be configured in such a way that the system will still be able to boot if one of the hard drives fails (no matter which one). read more...
permapage | score:7623 | -falko, October 24, 2011

Benchmarks: Linux software RAID

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RAID 0 linear vs. RAID 0 striped vs. RAID 1 (mirrored)...
Although having this reputation, my question was ? Was a RAID 1 System too slow?. Was it slower than not having any RAID? In fact, there are people that say that it is the other way round -these people say that having Software RAID 1 is faster than having just one hard disk drive.. In any case, who is right?

For that reason I'm going to ask the following question: "Is Software RAID slower than a simple hard disk?". We will try to repeat that benchmark again when a RAID card is available. The only reference that we found is in Chapter 9 Perfomance inside RAID Howto, but it's not very complete.
read more...
mail this link | permapage | score:7477 | -Ray, December 8, 2005

Nested RAID

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An excellent explanation of nested RAID configurations and their trade-offs in two parts: RAID-01 and RAID-10, and a second article covering combinations of RAID-5 and RAID-6 with RAID-1 and RAID-0. (There is also a background introduction / refresher article on basic RAID levels here.)
In general, its fairly easy to recognize a Nested RAID configuration because it will have two or more numbers designating the combination of standard RAID levels. For example RAID-10 uses both RAID-1 and RAID-0 to create the Nested RAID configuration. RAID-51 uses RAID-5 and RAID-1 to create that Nested RAID configuration, and so on.

The order of the numbers in the Nested RAID designation is important. The first number to the left is the lowest standard RAID level used (just above the disks). The next highest RAID level is the next number to the right and so on.
read more...
mail this link | permapage | score:7274 | -Ray, January 14, 2011
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Scripting: A parallel Linux backup script

Hacker Haiku

Why Programmers are not Software Engineers

Apple DIY Repair

Space Tyrant: A multiplayer network game for Linux

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Librenix T-Shirts and Coffee Mugs!

Missing the point of the Mac Mini

The life cycle of a programmer

Space Tyrant: Multithreading lessons learned on SMP hardware

The Real Microsoft Monopoly

Microsoft to push unlicensed users to Linux

Closed Source Linux Distribution Launched

Linux vs. Windows: Why Linux will win

Space Tyrant: A threaded game server project in C

Tutorial: Introduction to Linux files

Programming Language Tradeoffs: 3GL vs 4GL

VPS: Xen vs. OpenVZ

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The Network Computer: An opportunity for Linux

The short life and hard times of a Linux virus

Mono-culture and the .NETwork effect

Shadow.sh: A simple directory shadowing script for Linux

Download: Linux 3D Client for Starship Traders

Space Tyrant: A threaded C game project: First Code

Why software sucks

MiniLesson: An introduction to Linux in ten commands

No, RMS, Linux is not GNU/Linux

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