?
Solved

Rebuilding RAID 5 disk array ?

Posted on 2005-04-08
6
Medium Priority
?
632 Views
Last Modified: 2010-04-03
I have a 4 x 200 GB SATA RAID 5 disk array  with only  20%  used space.  Today one disk  failed and I took it out.

Is it safe to continue running this disk system with only 3 disks? Is there enough data redundancy to allow for another disk failure? Should I rebuild the  3 disk array now? Obviously, the failed disk will be replaced, but that might take some time.

The array is part of  a Red Hat 9 Linux  data server.
 
0
Comment
Question by:eruskov
6 Comments
 
LVL 97

Accepted Solution

by:
Lee W, MVP earned 1200 total points
ID: 13733804
RAID 5 allows for a MAXIMUM of ONE disk to fail.  If you have a failed drive already, then another failure and you lose ALL YOUR DATA.  Of course, rebuild it NOW.  Go to CompUSA, MicroCenter, or whatever your local computer store is and get a new drive NOW.

RAID 5 spreads the data over all disks in the RAID so in a sense, each disk in your 4 disk RAID 5 is 7% used; with one disk worth of space (not one physical disk) used for parity.  

In addition, your RAID drive is now operating slower as the controller has to reconstruct the data that it would normally be reading from the missing drive.
0
 
LVL 7

Assisted Solution

by:philby11
philby11 earned 200 total points
ID: 13733909
what leew said times ten,
don't risk your data
0
 
LVL 88

Assisted Solution

by:rindi
rindi earned 600 total points
ID: 13734226
It depends on how your raid has been setup. often you have 3 disks raided and an online spare. When one of the raided disks breaks down, the online spare should automatically take over the funtions of your failed drive. Once the array has been rebuilt to that online spare, another drive can go to nirwana. If all your drives are an active part of your array you must replace the bad drive with a good one and wait for the array to have been rebuilt before you can shoot another drive.

I don't know your array, was it built with online spare or not?
0
Configuration Guide and Best Practices

Read the guide to learn how to orchestrate Data ONTAP, create application-consistent backups and enable fast recovery from NetApp storage snapshots. Version 9.5 also contains performance and scalability enhancements to meet the needs of the largest enterprise environments.

 

Author Comment

by:eruskov
ID: 13740930
Thanks for the quick replies and advice!

I have a Relion Xeon 2U Servers from Penguin Computers and it came with the 4 x 200 GB SATA RAID 5 disk array that I mentioned above.

Today I bought two 200Gb Maxtor SATA drives and one of them is currently being rebuilt as part of the RAID array. There is one disk slot left and I would like to use it as an online spare. How do I do that?  

Any comments about  mixing disk sizes in a RAID arrays?


.
0
 

Author Comment

by:eruskov
ID: 13741830
Ok, I guess my last comments merit a separate question. I am closing this question and  splitting the points.
0
 
LVL 88

Expert Comment

by:rindi
ID: 13742031
thanx
0

Featured Post

Industry Leaders: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Create your own, high-performance VM backup appliance by installing NAKIVO Backup & Replication directly onto a Synology NAS!
Compliance and data security require steps be taken to prevent unauthorized users from copying data.  Here's one method to prevent data theft via USB drives (and writable optical media).
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
This tutorial will walk an individual through the process of installing the necessary services and then configuring a Windows Server 2012 system as an iSCSI target. To install the necessary roles, go to Server Manager, and select Add Roles and Featu…
Suggested Courses
Course of the Month15 days, 2 hours left to enroll

840 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question