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Obsolete Releases => SME Server 7.x => Topic started by: kevinb on September 05, 2007, 05:19:11 AM

Title: How to set up a RAID 5 without a hot spare
Post by: kevinb on September 05, 2007, 05:19:11 AM

Hello everyone,

I have a setup with two 36Gb SCSI drives in RAID 1. I want to add two more 36GB drives. I understand SME will convert this to a three disk RAID 5 with a hot spare.

Well ... I do not want the hot spare (I am assuming that a four disk RAID 5 that looses one disk is still a complete array - no data is lost just no more redundancy).

Can anyone give me instructions on how to set this up as a four disk RAID 5?


Thank you in advance for your help.


Kevin

Title: Re: How to set up a RAID 5 without a hot spare
Post by: dmajwool on September 05, 2007, 10:43:00 AM

My understanding is that SME will not convert between different RAID types when you add drives.

I believe if you want to change RAID types you should do a full backup, do a fresh install with the new RAID type, then restore your backup.

In SME 7.2 there is a switch available during install to disable allocating a spare drive.  See
http://forums.contribs.org/index.php?topic=37872.0

HTH, David.

Title: Re: How to set up a RAID 5 without a hot spare
Post by: kevinb on September 05, 2007, 05:11:22 PM

Thank you for the response.

From your link:

Quote

Disk redundancy
---------------
- The default disk layout has changed. A hot spare drive is
  automatically created if the system has more than two drives.
  A new boot option "nospare" has been added if you are certain that
  you do not want to create the spare.

How do I impliment the boot option "nospare"?

Also, I was able to go from a single disk to a RAID 1 no problem. But you are saying that I can't go from a RAID 1 to a RAID 5 automatically? I have to do a reinstall?

Bummer


Kevin

Title: Re: How to set up a RAID 5 without a hot spare
Post by: Stefano on September 05, 2007, 05:29:08 PM

Quote from: kevinb on September 05, 2007, 05:11:22 PM

Thank you for the response.

From your link:

How do I impliment the boot option "nospare"?

Also, I was able to go from a single disk to a RAID 1 no problem. But you are saying that I can't go from a RAID 1 to a RAID 5 automatically? I have to do a reinstall?

Bummer


Kevin

"nospare" is not a boot option, is a install one..

so, yes, you have to re-install sme if you want a raid 5 without spare disks

HTH

Ciao

Stefano

Title: Re: How to set up a RAID 5 without a hot spare
Post by: dmajwool on September 05, 2007, 05:58:40 PM

Quote from: kevinb on September 05, 2007, 05:11:22 PM

I was able to go from a single disk to a RAID 1 no problem. ..

The reason you could do that is because SME7 does single disk installs as if it is a degraded RAID1 with one of the disks missing.  When you added the second disk you were "correcting" the original "fault"

HTH, David

Title: Re: How to set up a RAID 5 without a hot spare
Post by: kevinb on September 05, 2007, 06:22:22 PM

Thanks guys,

David I suspect you are correct.

Stefano, Is the install option obvious or do i need to type in some code?


Kevin

Title: Re: How to set up a RAID 5 without a hot spare
Post by: Stefano on September 05, 2007, 06:30:55 PM

Quote from: kevinb on September 05, 2007, 06:22:22 PM

Thanks guys,

David I suspect you are correct.

Stefano, Is the install option obvious or do i need to type in some code?


Kevin

at boot prompt, type press F2 and/or F3 to read boot options.. you'll find everything there :-)

my 2c: maybe you could make some test using vmware..

Ciao

Stefano

Title: [SOLVED] Re: How to set up a RAID 5 without a hot spare
Post by: kevinb on January 17, 2008, 12:04:23 AM

The "nospare" switch worked ... thanks.

I also discovered that I can type "sme partition" at the install prompt after booting off of the CD and set up the software RAID array(s) anyway I want. The only downside is the text base GUI does not support modifying or creating logical volumes.

Kevin