• Contact Us
  • Home
  • About Us
  • News
    • Entertainment
    • Trending
  • IT
    • Code
    • Cloud
    • Linux
    • Splunk
  • Login
  • Register
Upgrade
CloudiBee
  • Contact Us
  • Home
  • About Us
  • News
    • Entertainment
    • Trending
  • IT
    • Code
    • Cloud
    • Linux
    • Splunk
No Result
View All Result
  • Contact Us
  • Home
  • About Us
  • News
    • Entertainment
    • Trending
  • IT
    • Code
    • Cloud
    • Linux
    • Splunk
No Result
View All Result
CloudiBee
No Result
View All Result
Home Linux

mdadm : Software RAID management in Linux

cloudibee by cloudibee
November 17, 2008
in Linux
0
0
SHARES
32
VIEWS
Share on FacebookShare on Twitter

Table of Contents

  • You might also like
  • Linux Change Password Command: Change password expiry in Linux
  • Top Open Source Email Servers

You might also like

Linux Change Password Command: Change password expiry in Linux

April 7, 2021
Email Servers

Top Open Source Email Servers

September 7, 2021
This utility helps to manage software raid devices on Linux. RAID devices are virtual devices created from two or more real block devices. This allows multiple devices to be combined into a single device to hold a single filesystem.  Some RAID levels include redundancy and so can survive some degre of disk failure.

Creating Raid Group md0 with local disks:

This command creates a RAID5 device named /dev/md0, with 3 disks /dev/sdb /dev/sdc /dev/sdd.

[root@foo15 ~]# mdadm –create –verbose /dev/md0 –level=5 –raid-devices=3 /dev/sdb /dev/sdc /dev/sdd
mdadm: layout defaults to left-symmetric
mdadm: chunk size defaults to 64K
mdadm: array /dev/md0 started.

Details of device md0(/dev/md0) using fdisk

Once /dev/md0 is created, you should be able to see the details using fdisk.

[root@foo15 ~]# fdisk -l /dev/md0
Disk /dev/md0: 293.6 GB, 293631295488 bytes
2 heads, 4 sectors/track, 71687328 cylinders
Units = cylinders of 8 * 512 = 4096 bytes

Details of the md disk using mdadm command

[root@foo15 ~]# mdadm –detail /dev/md0
/dev/md0:
        Version : 00.90.03
  Creation Time : Thu Sep 02 06:24:10 2008
     Raid Level : raid5
     Array Size : 286749312 (273.47 GiB 293.63 GB)
  Used Dev Size : 143374656 (136.73 GiB 146.82 GB)
   Raid Devices : 3
  Total Devices : 3
Preferred Minor : 0
    Persistence : Superblock is persistent

    Update Time : Thu Sep 02 07:01:44 2008
          State : clean
 Active Devices : 3
Working Devices : 3
 Failed Devices : 0
  Spare Devices : 0

         Layout : left-symmetric
     Chunk Size : 64K

           UUID : 0366e343:0366e343:0366e343:0366e343
         Events : 0.2

    Number   Major   Minor   RaidDevice State
       0       8       16        0      active sync   /dev/sdb
       1       8       32        1      active sync   /dev/sdc
       2       8       48        2      active sync   /dev/sdd

How to keep /dev/md0 persistant across reboots?

Add the md device entry to /etc/mdadm.conf

[root@foo15 ~]# mdadm -Es |grep md0
ARRAY /dev/md0 level=raid5 num-devices=3 UUID=0366e343:0366e343:0366e343:0366e343
[root@foo15 ~]# mdadm -Es |grep md0 >> /etc/mdadm.conf

Adding a disk to /dev/md0

[root@foo15 ~]# mdadm /dev/md0 -a /dev/sde
mdadm: added /dev/sde

/proc file for madadm : /proc/mdstat

[root@foo15 proc]# cat /proc/mdstat
Personalities : [raid6] [raid5] [raid4]
md0 : active raid5 sdb[0] sdd[2] sdc[1]
      286749312 blocks level 5, 64k chunk, algorithm 2 [3/3] [UUU]

unused devices: <none>
[root@foo15 proc]#

Previous Post

AIX Filesystem tips

Next Post

Linux : Network tunable parameters

cloudibee

cloudibee

Related Posts

Linux

Linux Change Password Command: Change password expiry in Linux

by cloudibee
April 7, 2021
Email Servers
Linux

Top Open Source Email Servers

by cloudibee
September 7, 2021
Linux

How to Determine Redhat Versions Command

by cloudibee
May 27, 2022
Linux

How-to Linux List Processes in 3 Simple Commands

by cloudibee
May 27, 2022
Linux

What is Cron Job in Linux?

by cloudibee
May 27, 2022
Next Post

Linux : Network tunable parameters

Leave a Reply Cancel reply

Your email address will not be published. Required fields are marked *

Premium Content

Podcast with Joe Fitzgerald, CEO, ManageIQ at VMworld 2011

May 27, 2022

CloudController® from InContinuum Software

May 31, 2022

Xen management : virsh commands

September 20, 2008

Browse by Category

  • Business
  • Cloud
  • Code
  • Debt
  • Entertainment
  • finance
  • Game
  • Health
  • IT
  • Lifestyle
  • Linux
  • Marketing
  • Misc
  • News
  • SEO
  • Services
  • Splunk
  • Sports
  • Tech
  • Technology
  • Tipes
  • Tips
  • Uncategorized

Browse by Tags

algorithm Apache Apache2 AWS Bash bash history Bind Blacklists Buffer C C++ CentOS Cerner chage Cloud Cloud Computing Cloud jobs Cloud Storage Cloud Suite Commands Compliance Cron job Debian Directory DMS DNS Docker Dovecot drop cache Email servers Enteprise Cloud Enterprise External FAT32 Format kernel Linux linux kernel Nirvanix passwd Sendmail SSH SSL Terminal Ubuntu

About CloudiBee

cloudibee logo


CloudiBee is an open-source for people who love technology. Here we will be sharing lots of technical information over the web so that a lot of people visit us and gain some knowledge. We are a completely open to all platform. We assure you that you can easily get any info and updated news about the tech world from us. Let's begin with us!

Hot Topic

Debt Collection & Debt Collection Scams

by Swati
August 8, 2022
0
Debt Collection Scams

With inflation at record levels, many consumers are having trouble juggling all their bills. And some are even missing payments....

Read more

Recent News

Business

The main reasons for the startup fails. How to avoid failure?

July 21, 2022
Business

Hacks for packing wine glasses so they don’t break

July 21, 2022
Business

5 tips to ensure that your movers are always on time.

July 21, 2022

CloudiBee. © 2021. All Rights Reserved

No Result
View All Result
  • Contact Us
  • Home
  • About Us
  • News
    • Entertainment
    • Trending
  • IT
    • Code
    • Cloud
    • Linux
    • Splunk

CloudiBee. © 2021. All Rights Reserved

Welcome Back!

Login to your account below

Forgotten Password? Sign Up

Create New Account!

Fill the forms bellow to register

All fields are required. Log In

Retrieve your password

Please enter your username or email address to reset your password.

Log In