Want to protect your cyber security and still get fast solutions? Ask a secure question today.Go Premium


Raid 5 Configuration Clarification

Posted on 2006-05-15
Medium Priority
Last Modified: 2010-04-03
My HP ACU is showing this RAID 5 configuration (which I inherited):

Physical Drives:

#1 - 18.2 gb
#2 - 18.2 gb
#3 - 18.2 gb
#4 - 18.2 gb
#5 - 18.2 gb  (spare)
#6 - 18.2 gb

Logical Drives:

Disks 1-4 (50.2 gb total space)  << partitioned as drive C:
Disk   6    (16.9 gb total space)  << partitioned as drive E:


One array with the above two logical drives.

So my question is this.  Is Disk #6 (partitioned as drive E:) part of the RAID 5 configuration?  I'm sure the answer is yes.  I don't want it to be a simple volume (stand alone drive) without redundancy.
Question by:mcnuttlaw
  • 2

Accepted Solution

jdietrich earned 800 total points
ID: 16684164
Raid 5 spreads the information accross all drives.  You have 5 drives in the array, the total usable space is 72.8 Gigs.  Looks like it is partitioned ini 2, one of 50.2 and the other 16.9.  I think it is all the same array.  If the 1-4 were in their own Raid 5 array the usable disk would be 54.59.  Plus most raid adapters will not allow a stand alone drive not designated as a spare to be used.  You should be able to verify in the disk manager in administrative tools, or the raid software that HP provides.

Author Comment

ID: 16684236
My raid software shows one array, 5 physical drives, two logical drives (50.2 and 16.9).

So thanks for helping me verify that my sixth drive is in fact part of the array.
LVL 70

Assisted Solution

by:Gary Case
Gary Case earned 200 total points
ID: 16684501
Just to be sure you understand the disparity in the numbers ...

Your array is, as noted, comprised of 5 18.2gb drives, which yields a total available space of 4 x 18.2 = 72.8gb   But those are "disk manufacter's" gigabytes (= 1,000,000,000 bytes/gigabyte), NOT "computerese" gigabytes (= 1024x1024x1024 = 1,073,741,824 bytes/gigabyte).   Note that 72.8gb in "disk drive-ese" is 67.8gb in "computerese."

Your RAID software is reporting the sizes of your partitions in "computerese,"  so that's why you only see 50.2gb and 16.9gb ==> a total of 67.1gb.   The difference between this and 67.8 is easily accounted for in rounding errors (look at more digits than just 50.2 and 16.9) and the fact that the drives most likely don't have "exactly" 18.2gb -- and the actual array size will be 4 x the SMALLEST drive's capacity.

Author Comment

ID: 16684589
Thanks garycase.

Featured Post

Technology Partners: We Want Your Opinion!

We value your feedback.

Take our survey and automatically be enter to win anyone of the following:
Yeti Cooler, Amazon eGift Card, and Movie eGift Card!

Question has a verified solution.

If you are experiencing a similar issue, please ask a related question

Finding original email is quite difficult due to their duplicates. From this article, you will come to know why multiple duplicates of same emails appear and how to delete duplicate emails from Outlook securely and instantly while vital emails remai…
Compliance and data security require steps be taken to prevent unauthorized users from copying data.  Here's one method to prevent data theft via USB drives (and writable optical media).
This video teaches viewers how to encrypt an external drive that requires a password to read and edit the drive. All tasks are done in Disk Utility. Plug in the external drive you wish to encrypt: Make sure all previous data on the drive has been …
This Micro Tutorial will teach you how to reformat your flash drive. Sometimes your flash drive may have issues carrying files so this will completely restore it to manufacturing settings. Make sure to backup all files before reformatting. This w…
Suggested Courses
Course of the Month15 days, 8 hours left to enroll

576 members asked questions and received personalized solutions in the past 7 days.

Join the community of 500,000 technology professionals and ask your questions.

Join & Ask a Question