LinuxQuestions.org
Download your favorite Linux distribution at LQ ISO.
Go Back   LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware
User Name
Password
Linux - Hardware This forum is for Hardware issues.
Having trouble installing a piece of hardware? Want to know if that peripheral is compatible with Linux?

Notices


Reply
  Search this Thread
Old 01-21-2005, 03:32 PM   #1
ray_h
LQ Newbie
 
Registered: Jan 2005
Posts: 1

Rep: Reputation: 0
Hardware Raid 5 device files


I have added a 7 disk Raid 5 array. This is a powervault 220s from Dell which provides the hardware raid.

How do I partition this array? I can see the individual disk device files.
But if I were to partition one of those the data would be all on one disk instead of striped which would negate the hardware Raid 5.

Is there a device file that references the whole raid? When I am in Red Hat it shows the Raid as being a system device with device file /dev/sg2.

An fdisk on /dev/sg2 just hangs.

Thanks for any help.
 
Old 04-16-2005, 05:31 PM   #2
t3gah
Member
 
Registered: Dec 2004
Distribution: SuSE, RedHat, ubuntu, Debian
Posts: 734

Rep: Reputation: 30
Re: Hardware Raid 5 device files

Quote:
Originally posted by ray_h
I have added a 7 disk Raid 5 array. This is a powervault 220s from Dell which provides the hardware raid.

How do I partition this array? I can see the individual disk device files.
But if I were to partition one of those the data would be all on one disk instead of striped which would negate the hardware Raid 5.

Is there a device file that references the whole raid? When I am in Red Hat it shows the Raid as being a system device with device file /dev/sg2.

An fdisk on /dev/sg2 just hangs.

Thanks for any help.
When using a Dell PERC and a RAID 5 the logical drive comprises of all the drives and the striping is in the BIOS and away from the operating system. So the O/S should see one big disk minus one complete hard disk space which is what supplies the redundancy. You can't negate the stripe from a hardware BIOS controlled RAID 5. If it's a true hardware RAID which PERC's do then the operating system has no idea how many physical hard disks there are that make up the RAID array when it's a level 5 RAID.

The utilities you speak of or are asking about are available on your PowerVault CD if it's a later revision that includes Linux utilities. Other than that there's also the Dell OpenManage Server Assistant which also has drivers, utilities and documentation for Linux usage which again must be a later rev of that CD. I'd suggest looking at http://support.dell.com for the RAID utils if RAIDTOOLS2 won't work for you.

As for fdisk hanging, make sure you have the Linux driver from Dell.com and not the one that come with your Operating System. Before you install the driver also check the Dell.com Support website for any notices and/or firmware updates that the controller might require to install the Linux driver and the utility if it's a Dell PERC.

And as a note... if you see more than one disk or the new disk you haven't added into the current array or you didn't initialize or scrub the RAID 5 array. When adding a drive you select or tag it from the CTRL-A or CTRL-M the process of which is too detailed for me to go into here. The complete howto is at http://support.Dell.com.
 
Old 04-16-2005, 05:31 PM   #3
t3gah
Member
 
Registered: Dec 2004
Distribution: SuSE, RedHat, ubuntu, Debian
Posts: 734

Rep: Reputation: 30
Lightbulb Re: Raid Wiki

There's a complete explanation of RAID types here at LinuxQuestions.org in the Linux Wiki section.

Last edited by t3gah; 04-16-2005 at 05:35 PM.
 
  


Reply


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
Dell "CERC" Raid-5 w/CENT OS. Is this true hardware RAID or just an expensive card? fireman949 Linux - Hardware 2 06-24-2005 06:44 PM
RAID Hardware majicrobot Linux - Software 2 09-23-2004 07:10 PM
help with hardware RAID MeanJoshGreen Debian 4 03-03-2004 09:08 PM
Hardware RAID PCI Card (Hardware?) MasterC Linux - Hardware 1 03-01-2003 02:19 AM
Software RAID vs Hardware RAID system Linux - General 3 12-25-2001 09:11 PM

LinuxQuestions.org > Forums > Linux Forums > Linux - Hardware

All times are GMT -5. The time now is 04:10 AM.

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