Help answer threads with 0 replies.
Go Back > Forums > Linux Forums > Linux - Newbie
User Name
Linux - Newbie This Linux forum is for members that are new to Linux.
Just starting out and have a question? If it is not in the man pages or the how-to's this is the place!


  Search this Thread
Old 06-04-2009, 06:41 AM   #1
LQ Newbie
Registered: Jun 2009
Posts: 2

Rep: Reputation: 0
Mirroring a disk in Linux RHEL AS4


I'm very new to Linux hence this post. I have been asked to mirror the root disk on a Linux server running RHEL AS4 and I have no idea where to start. The layout of the root disk is as follows:-

/dev/sda6 2.0G 1.6G 352M 82% /
/dev/sda1 198M 12M 176M 7% /boot
none 505M 0 505M 0% /dev/shm
/dev/sda8 17G 576M 16G 4% /home
/dev/sda9 1012M 677M 284M 71% /opt
/dev/sda3 4.0G 41M 3.7G 2% /tmp
/dev/sda2 4.0G 2.5G 1.3G 67% /usr
/dev/sda5 4.0G 1.1G 2.8G 28% /var

Can someone advise me on how to perfrom this task please as I'm currently struggling with it?
Old 06-04-2009, 07:47 AM   #2
Registered: Apr 2009
Posts: 107

Rep: Reputation: 19
The root disk is in your case /dev/sda6 (the one marked as '/' which means root). To make a copy you can use the 'dd' tool, but please read the man page before doing something that you regret.

It is not clear what is truely asked of you:
- making a backup of the root partition only
- making a backup of the whole root file system (this would require to backup all the mounted partitions as well, like /usr, /var and the others)
- setting up a hard disk mirror with some other hard disks to continually mirror all data changes

Linux Archive

Last edited by soleilarw; 06-18-2009 at 04:24 AM.
Old 06-04-2009, 08:24 AM   #3
LQ Newbie
Registered: Jun 2009
Posts: 2

Original Poster
Rep: Reputation: 0
From what I understand they require all partitions to be mirrored to another disk ( this is yet to be installed into the server ). So if the primary root disk were to fail they could run off the root mirror.

So basically I would like it so that all changes are mirrored onto the second disk.
Old 06-04-2009, 08:39 AM   #4
Registered: Dec 2004
Location: Alabama
Distribution: Slackware, Solaris,Fedora, CentOS, Redhat, SGI
Posts: 65

Rep: Reputation: 18
Look into dd and mdadm This may help

You will need a partition the same size created first on different disk

fdisk /dev/sdb <Read the info from using the M command>

use disk type "fd" = Linux Raid

mdadm -c /dev/md0 -n 2 -l 1 /dev/sda6 /dev/<new disk part>
Old 06-05-2009, 01:00 AM   #5
LQ Guru
Registered: Aug 2004
Location: Sydney
Distribution: Centos 6.9, Centos 7.3
Posts: 17,357

Rep: Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367Reputation: 2367
Upper and lower case 'c' have different meanings:
In the above case, you want upper: C
Old 06-05-2009, 05:07 AM   #6
Registered: Apr 2009
Posts: 107

Rep: Reputation: 19
It seems that RAID mirroring is what they want from you. Not overly complicated, but you should get some complete tutorial on the topic - and also get some cheap old PC to test the procedure before playing with it on a production environment.


Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is Off
HTML code is Off

Similar Threads
Thread Thread Starter Forum Replies Last Post
Proxy server setup in Linux RHEL AS4.0 rahul.k_001 Linux - Networking 1 07-30-2007 03:47 AM
startx and rhel as4 Ammad Linux - General 2 04-14-2006 08:06 PM
Japanese input in RHEL AS4 scylla Linux - Software 0 07-29-2005 12:24 AM
RHEL AS4 download links! Verylinux Linux - Distributions 1 02-25-2005 06:05 PM
RHEL AS4 download links! Verylinux Linux - Software 1 02-25-2005 10:20 AM

All times are GMT -5. The time now is 06:32 PM.

Main Menu
Write for LQ is looking for people interested in writing Editorials, Articles, Reviews, and more. If you'd like to contribute content, let us know.
Main Menu
RSS1  Latest Threads
RSS1  LQ News
Twitter: @linuxquestions
Facebook: linuxquestions Google+: linuxquestions
Open Source Consulting | Domain Registration