RECO? SATA RAID controller

[thedaver]

I'm curious on practical experience using linux (any distro) with any particular RAID controller supporting SATA drives in RAID 1, 10 or 5 config.

Concerns:
- driver support
- kernel issues
- is RAID Bootable?
- support, monitoring, management software (in Linux, to complement BIOS from controller card).

For context, I'm interested in building a box for my own use, not really Enterprise Data Center grade quality/availability. Feedback most appreciated!


D.E.R. Management - IT Project Management Consulting

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[QatQat]

If you were talking about SCSI RAID support my answer would be positive to all your questions, but I have no experience with SATA Raid.

My guess is that new kernels have all necessary modules for that but I would like somebody else to give us more info.

CHeers

QatQat

Life is what happens when you are making other plans.

 

[thedaver]

Found this site:

http://linux-ata.org/

D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/

 

[smah]

I've got a Dell server running RHES3 using a 6 port SATA controller. They brand it as a 'CERC' (Cost Effective Raid Controller), but I believe that it's actually made by Adaptec. It runs 3 drives in Raid 5 arry which are the boot drives. Dell includes software for monitoring & managment.

 

[msound]

Most raid controllers really only offer a software raid. It's not a bad thing, but i opted for a dupli-disk by arco.

http://www.arcoide.com.

It offers a true hardware raid that is OS independent.

 

[smah]

msound, could you provide some more information about your statement above? I'd like to know where you set the distinction: Hardware without some software (instructions) won't do anything. Software without some hardware (to do the work) won't do anything either. Every raid controller must have some of each.

 

[msound]

The raid controller I use controls everything through its firmware. When I first installed it i used boot media to configure the mirroring, and once that's done it's all set. The OS views the raid array as a single disk, without requiring any raid management software in the OS itself. Other onboard raid controllers I've tried didn't work with a standard installation of linux. I'd have to designate it as a raid isntallation, or the os would just install on one hdd. That's just been my experience.

 

[thedaver]

smah,

Yes, apparently there are 2 types of RAID cards out there. Those that are fully hardware driven (much like hardware modems) are capable of self-operating and do not expose their internal workings to the OS such that the OS MUST manage the disks. Just one big disk!

Software driven RAID cards apparently rely on the OS to do some of the heavy lifting using quasi-drivers. Given Linux' history around software modems and the stated distaste on the link I reference for Software RAID cards, I'm inclined to use hardware-only RAID.

And, all of this is apparently different from the SOFTWARE RAID supported by Linux itself by putting all the work on the OS to manage a very fake raid from plain IDE devices.



D.E.R. Management - IT Project Management Consulting

http://www.dermanagement.com/