Configuring Raid 1 in 2 computer

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pfsms
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Joined: 2018/02/08 20:54:46

Configuring Raid 1 in 2 computer

Post by pfsms » 2018/02/08 21:12:54

Hello all
i`m newbie in Centos Operation and i want to configure Raid 1 in 2 computer

i surf the internet and i found tutorial about configure Raid 1 in 1 computer system for example i used this tutorial from youtube

" How to configure RAID1 on CentOS 7 "
https://www.youtube.com/watch?v=7u4ml7P3iX4

i have 2 computer with centos operation and they are connected to each other and the ping test between them is OK

my question is that how can i configure RAID 1 on 2 separated computer

thanks in advance

hunter86_bg
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Re: Configuring Raid 1 in 2 computer

Post by hunter86_bg » 2018/02/09 05:17:16

Raids can be done only locally.
I think you are talking about DRBD.If you do need drbd , you can check some of the steps here
Have in mind that you can use one way (active - passive) or two way (active - active ) DRBD.

Note: The packages are not in CentOS repo, but external one !

pfsms
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Re: Configuring Raid 1 in 2 computer

Post by pfsms » 2018/02/09 12:23:03

hunter86_bg wrote:Raids can be done only locally.
I think you are talking about DRBD.If you do need drbd , you can check some of the steps here
Have in mind that you can use one way (active - passive) or two way (active - active ) DRBD.

Note: The packages are not in CentOS repo, but external one !

thanks for your reply no is not DRBD
somebody told me i could do raid 1 in 2 computer system by using ISCSI
do you know any thing about that ?

my scenario is this:
i have 2 computer system that have 100 GB hard disk
for example i copy a file about 1 GB to my first computer system and i want to access that file in my second computer system by using Raid and ISCSi

would you please help me ?

thanks in advance

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jlehtone
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Re: Configuring Raid 1 in 2 computer

Post by jlehtone » 2018/02/09 13:32:55

pfsms wrote:somebody told me i could do raid 1 in 2 computer system
Misunderstandings can occur in many ways.

First, RAID-1 is a "mirror". You have one logical filesystem and every file that you write is written to not only one physical drive, but to (at least) two.

You have two physical drives, separated by network. RAID-1 like write would be slowed down by "the other" disk being behind network. There are distributed storage implementations. See CEPH.

ISCSI does allow "attaching" a drive to remote computer over network. One of your computers could "give" its disk to the other. The second computer would have two disks to play with, but one over network.

LVM, Logical Volume Manager, does have clvm, clustered LVM mode so that all members of the cluster can see same volume group. LVM does support RAID-1 -like volumes too. The members of cluster. What to do when a member is down? How to know that a member is down? Does it know that it is down? How to recover? Who has the "good" copy?

Lets say that all members see same filesystem. What if both computers attempt to modify same file simultaneously? How are the writes synchronized to keep the filesystem coherent? There are clustered filesystems.

The DRBD is among ways to "cluster".


However
for example i copy a file about 1 GB to my first computer system and i want to access that file in my second computer
The traditional solution for this is file sharing. One machine acts as NFS server and shares (some) files to the other. The other machine is NFS client that mounts shared directories. Both machines can act as servers and clients.
... by using Raid and ISCSi
It seems that you have selected a solution and ask how to implement it, rather than asking what solutions would be appropriate for your actual need.
Are you sure that you don't have an XY problem? http://xyproblem.info/

hunter86_bg
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Re: Configuring Raid 1 in 2 computer

Post by hunter86_bg » 2018/02/09 15:53:35

It seems I'm missing something. Can you explain what is the end goal?

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