Mobo raid vs LSI/3Ware

[jose]

Hi everyone,

I'm familiar w/ hardware controllers. LSI/3Ware

My friend is building a sata server to record video feeds.

Because of insurance claims are up.. ie. ppl. faking injuries.


Anyway I'm trying to convince him that he should stick to a hardware controller.. He's going to use 4 - WD 500g drives in raid 5.

I've never used onboard raid so I'm not aware of any potential problems. ie. rebuilds, recovering from failures.


Can you guys list any problems w/ mobo raid ?

He's planning on using the Asus P5W64 WS Professional mobo..

http://usa.asus.com/products.aspx?l1=3&l2=11&l3=248&model=1341&modelmenu=1

Thanks for the info.

Regards,
Jose

 

[SuperNaruto]

software vs hardware and you can add areca to the hardware list ...

hardware = less demanding on the cpu, rebuilds automatically

 

[Matthias99]

Originally posted by: SuperNaruto
software vs hardware and you can add areca to the hardware list ...

hardware = less demanding on the cpu, rebuilds automatically

"Software" RAID can rebuild automatically too; it just depends on the controller and drivers.

One (potential) problem with onboard RAID is that if your motherboard dies and you can't get an exact replacement (think "motherboard dies five years from now and the company that made it has gone out of business"), or you want to move the array to another system, you might have issues. With an add-in controller, you just move the controller along with the array.

You can't generally take a RAID array from one kind of chipset and put it on a different one, even if they're made by the same company. Sometimes you can; e.g. LSI supports this across most of their recent RAID controllers, as long as both controllers support the kind of array you have. But don't count on it.

CPU usage for software RAID controllers (or even 'pure' software RAID, through the OS) is not usually an issue unless you are writing lots of data and using RAID5/RAID6 (the XOR calculations can eat up a lot of memory bandwidth and CPU time). The overhead for RAID0/RAID1 is very small.

 

[Seekermeister]

Do controller cards have a longer lifespan, so that you might find an exact replacement of it some years later?

 

[Matthias99]

Originally posted by: Seekermeister
Do controller cards have a longer lifespan, so that you might find an exact replacement of it some years later?

Potentially, that can also be a problem. I would say that they do tend to be produced for longer amounts of time than motherboards (and usually in larger numbers than most enthusiast motherboards). They're also simpler, and so probably less likely to fail electrically. If this is a concern, you might want to look at products that can migrate arrays forward onto newer products -- or a higher-end enterprise solution that will guarantee support for a long time.

Worst-case (for either onboard or add-on controllers), either the manufacturer of the controller or a data recovery company can usually (for a fee) pull data off of 'obsolete' RAID arrays.

 

[jose]

If your mobo fails, then you get an exact replacement.

What happens to the array ? Do you just create it again and the original data is intact ? or worse does it re-init the array loosing the data ?


Thanks for the info.

Regards,
Jose