Determining Current RAID

[jw]

I just walked into a new job that has an Xraid and I am rather unfamiliar with Apple server products in general and would like to verify something with the crowd:

First some background:

In RAID Admin, it shows that there are 14 drives, each 698.63GB. Google shows that these hard drive models are 750GB. Question about this in a sec.

RAID Admin shows that these drives are in two Arrays of seven drives each, both RAID 0.

Finally, the Events tab of RAID Admin shows that a couple of months ago, there was an error:
Disk 9 Reported An Error. COMMAND:0x25 ERROR:0x49 STATUS:0x51 LBA:0x57464218.
A couple of days later, there is an event
Error Status Cleared Using Service ID Button
Currently, no non-green lights are showing on the front of the Xraid.

Questions:
I know my RAID, but not SANs in general (LUNs, etc) nor Xraid or its interfaces. I can see in this interface no indication that the two arrays are mirrored against each other, but I am not familiar enough with the interface to really know for certain. Am I missing either a different tool/interface or missing a basic assumption of Xraid here? Is this really saying that this Xraid is running entirely striped with no redundancy at all?!? Fast it would be, yes, but that sounds a bit crazy and just wanted to verify that I am not missing a key piece of data here.

If there is no mirroring or other redundant use, where is that last 50GB per drive going?

And the big one: Checking around online (including these forums), this drive error indicates that things are not critical but that the drive ought to be replaced reasonably soon. If this were a nice redundant array I could just hot swap out a drive and all would be well. However, if this has no redundancy, removing a drive from a RAID 0 array is a Bad Idea. What would you recommend?

Thanks in advance for any light you can shed on this for an experienced sysadmin but a newbie to this specific technology!

[singlemalt]

Hi jw,
RAID 0 is RAID 0. So yeah it pretty much sounds you like you've got 2
separate stripes with no redundancy going on there. Not unheard of in a SAN
if whats needed is speed or space and the data is backed up regularly or is so
transitory that backing up isn't really needed due to fast obsolescence.
With XserveRAID you could only mirror across the controllers with a Software Mirror
(i.e. Disk Utility RAID).

The missing 50GB isn't really missing. I suspect you're running into the old base 10 vs. base 2 counting discrepancy.
http://support.apple.com/kb/TS2419
...
Storage device manufacturers measure capacity using the decimal system (base 10), so 1 gigabyte (GB) is calculated as exactly 1,000,000,000 bytes. The capacity of the storage media in your Mac (Mac OS X v10.5 or earlier), iPad, iPod, iPhone and other Apple hardware is measured using this decimal system. We set this out on our product packaging and on our website through the statement "1 GB = 1 billion bytes."
...
When you view the storage capacity of your Mac (Mac OS X v10.5 or earlier), iPod, iPhone, iPad, or other electronic devices within its operating system, the capacity is reported using the the binary system (base 2) of measurement. In binary, 1 GB is calculated as 1,073,741,824 bytes. This difference in how the decimal and binary numeral systems measure a GB is what causes a 32 GB storage device to appear as about 28 GB when detailed by its operating system, even though the storage device still has 32 billion bytes, as reported.