Raid Ready Hard Drive vs Standard Hard drives

Question

What is the difference between normal data hard drives and Raid Ready Hard Drives?

I am planning to build a server with 6x2TB hard drives and i have been quoted raid ready Hard drives nearly at 250$ per 2 TB hdd, what is the advantage of going for these over lets say 70$ 2TB Hard drives.

I am planning a file server for a small office round about 20-> 30 people Maximum no big files mainly documents and then overnight backup of some VMware images.

I am looking for the most cost effective way to do this. should i really invest in "raid ready" hard drives or is it just a marketing act.

My Provider of the parts told me if i go for standard hard drives " you will risk compromising data integrity" is this true?

thanks in advance.

Solution

RAID drives typically are of a higher quality but also have different error handling characteristics.

There is a good article at http://en.wikipedia.org/wiki/Time-Limited_Error_Recovery which describes the Western Digital feature although similar features apply to the major disk manufacturers

From the WD web site...

When an error is found on a desktop edition hard drive, the drive will enter into a deep recovery cycle to attempt to repair the error, recover the data from the problematic area, and then reallocate a dedicated area to replace the problematic area. This process can take up to 2 minutes depending on the severity of the issue. Most RAID controllers allow a very short amount of time for a hard drive to recover from an error. If a hard drive takes too long to complete this process, the drive will be dropped from the RAID array. Most RAID controllers allow from 7 to 15 seconds for error recovery before dropping a hard drive from an array. Western Digital does not recommend installing desktop edition hard drives in an enterprise environment (on a RAID controller).

Comments

[the-wabbit]

Another important point would be that "desktop drives" typically do not have a 24x7 certification - the manufacturer did neither design nor test the drives to run continuously over the period of several years. This has led to problems in the past, the IBM / Hitachi Deskstar case being probably one of the most famous ones.

[steve.lippert]

We have been running desktop drives in a RAID setup for a few years and just had our first failure. We aren't using a RAID controller and instead are just doing it in software (mdraid). This however requires that we have a strong backup/recovery setup.