[Bassetlug mailing] Setting up RAID

[philip jones]

To Martin
I have currently install fedora 10 which has the option to set up raid1+0 
(10) .once installed it was time to find out whether the drives were working 
as a raid array or separate so using our test
mdadm  /dev/sda
we get "sda is not an md array"
this where we went wrong
we should type
mdadm /dev/md0
we get "148.84gib raid10  4 devices 0 spares use mdadm --detail for more 
information.
the raid10 is now running
Now I have to set it up as a web server i wounder if apache has been 
installed ?
kind regards philip

----- Original Message ----- 
From: "Danny Roberts" <droberts23 at csc.com>
To: "LUG Mailing list for Bassetlaw and N. Notts" 
<bassetlug at mailman.lug.org.uk>
Sent: Thursday, March 19, 2009 3:55 PM
Subject: Re: [Bassetlug mailing] Setting up RAID


> We initially tried using the software RAID (via the Ubuntu
> Installer/Partitioner) but it seemed incapable of creating the RAID 10
> setup we wanted so Philip switched it over to hardware RAID.
>
> RAID 5 is great (we use a lot of it at work albeit on that "other OS") but
> that would lack the improved performance Philip wanted from the RAID 10
> configuration.
>
> I think playing around with RAID and finishing off Philip's web server
> could be great for the next LUG meeting, I know I'm certainly interested
> in learning more. And of course if no one else wants the Compaq servers
> etc I'd love to give them a new home ;-)
>
> Mark do you have any experience in setting up complex/esoteric RAID setups
> like RAID 50, RAID 60 or even RAID 100? That would probably be beyond the
> scope of one of our meetings but I've done a lot of reading up on RAID
> today and its whetted my appetite.
>
> Kind Regards
>
> DANNY ROBERTS
> EMEA Cross Platform Services - Evergreen
> CSC
>
> GOS   I    p : +(44) 1246 523181    I    droberts23 at csc.com    I
> www.csc.com
>
> CSC, Block A, Manor Offices, Old Road, Chesterfield, S40 3QT.
>
> CSC • This is a PRIVATE message. If you are not the intended recipient,
> please delete without copying and kindly advise us by e-mail of the
> mistake in delivery.  NOTE: Regardless of content, this e-mail shall not
> operate to bind CSC to any order or other contract unless pursuant to
> explicit written agreement or government initiative expressly permitting
> the use of e-mail for such purpose • CSC Computer Sciences Limited •
> Registered Office: Royal Pavilion, Wellesley Road, Aldershot, Hampshire,
> GU11 1PZ, UK • Registered in England No: 0963578
>
>
>
>
> Rev Mark Pengelly <minister at thecrossing.co.uk>
> Sent by: bassetlug-bounces at mailman.lug.org.uk
> 19/03/2009 15:44
> Please respond to
> "LUG Mailing list for Bassetlaw and N. Notts"
> <bassetlug at mailman.lug.org.uk>
>
>
> To
> "LUG Mailing list for Bassetlaw and N. Notts"
> <bassetlug at mailman.lug.org.uk>
> cc
>
> Subject
> Re: [Bassetlug mailing] Setting up RAID
>
>
>
>
>
>
> Was Philip's discussion all relating to mdadm? We use that on the
> crossings' server. it is of course 'software raid' not to be confused
> with a hardware raid controller.
>
> Occasionally we have had glitches with our raid 1 setup, ie a disk drops
> out of the raid and then md commands are used to add it back in. So far
> it has always done so, although sometimes we have had to do a cold
> reboot of the machine.
>
> Hardware raid is preferable if available. Most compaq servers raid
> hardware is supported in linux and can usually see a partition as a boot
> device when installing, once the array is setup using the proprietary
> software (SmartStart in the case of compaq).
>
> I have a pci hardware raid card on my main ubuntu machine, but never
> really got it working properly.
>
> Many modern motherboards with sata raid are actually only using
> (windows) software to create the raid, it's not full proper hardware
> raid (I think).
>
> if anyone wants to play with raid I have 2 x compaq 1500 servers, one
> with 5 drives, one with 3 drives in it. I had redhat 6 running merrily
> on it about 5 years ago, I also have a scsi attached array case with
> another 7 drives in (only 2.1gb per drive). I've been meaning to clear
> this out for months, free to a good home! only catch - you need to have
> ear defenders on when all the drives start up! i ran mine in the
> garage!! Perhaps I'll bring it to bassetLUG show how to set it up and
> then someone else could take it home!?
>
> Sounds good Philip, sorry I missed it! Raid is definately cool, what
> about raid 5?! my favourite!
>
> Mark
>
>
>
> On Thu, 2009-03-19 at 13:55 +0000, MJ.Wells wrote:
>
>> Good to see 'old' and 'new' members at the meeting last evening where
> Philip
>> gave us a very informative demonstration of setting up RAID in Ubuntu.
>>
>> Philip told us that he had occasionally seen problems when he set up
> some
>> systems which he felt were due to not having identical drives in the
> array
>> as is recommended.
>>
>> Philip then showed us that  setting up the RAID in the BIOS causes Linux
> to
>> be unable to find the boot loader so that the most expensive of
> equipment
>> just loops at boot as it could save me much time in the future. It seems
>> that the boot partition has to be excluded from RAID.
>>
>> Philip went on to explain the difference between RAID 0 (striped) and
> RAID 1
>> (mirrored) along with the more complex RAID 10 (1+0) which combines
> both.
>> After a detailed setup of the partitions using the hardware RAID which
> led
>> to the failure to boot, Philip showed us the process of setting up the
>> drives in the Ubuntu Server install. Finally we looked at leaving the
> setup
>> of the RAID until Ubuntu had been fully loaded on some of the disks.
>>
>> Unfortunately, even though we extended our evening until well past 10pm
> as
>> we were enjoying the demonstration so much, we had to leave the full use
> of
>> mdadm until another time.
>>
>> I have not encountered this technology before and have learned a lot.
> Thanks
>> Philip for a very informative and useful demonstration. Now ... I wonder
>> where can I lay my hands on four unwanted 500Gb-ish drives so that I can
> try
>> it all for myself?
>>
>> Martin
>>
>>
>>
>>
>> _______________________________________________
>> Bassetlug mailing list
>> Bassetlug at mailman.lug.org.uk
>> https://mailman.lug.org.uk/mailman/listinfo/bassetlug
>>
> _______________________________________________
> Bassetlug mailing list
> Bassetlug at mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bassetlug
>
>
> _______________________________________________
> Bassetlug mailing list
> Bassetlug at mailman.lug.org.uk
> https://mailman.lug.org.uk/mailman/listinfo/bassetlug