RAID – Redundant Array of Inexpensive / Independent Disks
Info collected from here: http://eshop.macsales.com/shop/hard-drives/sata/RAID_Guide/Learn_About_RAID_5
Great article on RAID: https://www.prepressure.com/library/technology/raid
and as well as wiki and other sites.
Note: RAID 10 (RAID 1+0) and RAID 01 (RAID 0+1) are different.
RAID 0 (Stripe)
Requires 2 or more drives. Hardware or software RAID can be used to implement.
High speed and we get full capacity
No data safety / parity
RAID 1 (Mirror)
RAID 5 (Stripe with parity)
RAID 5 – Data is striped like RAID O. Should have minimum of 3 drives. Parity information is spread on all available drives. Parity information will be as much as a whole single drive.
> Good read performance
> Data redundancy. Data can be recovered in case of a drive crash on a drive.
RAID 5 Parity
RAID 6 is similar to RAID 5 except it has dual parity.
Combination of RAID 0 and RAID 1. Which means both striping and mirroring. There are no parity in RAID 10.
If RAID 5 requires 3 HDDs then RAID 10 requires 4 HDDs.
RAID 0+1 vs RAID 10
There are also RAID 50, 60 and 100. Check Wikipedia.
Netapp (such as FAS3220) uses RAID called RAID-DP. It uses Netapp’s variant of RAID 6 with dual parity with hot spare HDDs. As a result, as soon as disk get fails, spare HDD is automatically replaced by the controller.
NetAPP FAS3220 controller and HDDs in RAID-DP
This one I downloaded from net
Configure RAID 0 (Striping) on Dell Power Edge R710
The server has 5 HDDs and we are going to configure them in RAID 0 striping.
- Reboot the server and press Ctrl + R
- Note: this is via iDRAC
Reboot the server -> Ctrl + R -> Clear the existing RAID configuration (if any) -> Create new RAID configuration (Here we set RAID level) -> Check / select the HDDs -> Give RAID name -> Initialize Disks -> Ctrl + N to goto next page.
3. Place cursor in Controller 0 and Press F2. F2 – Operations
4. Select clear config
5. Select yes and clear configuration
Now place cursor in Controller 0 and press F2
7. Again press F2 operations
8. Select Create New VD
9. Here we have 5 HDDs and we are going to configure in RAID 0 configuration. Here make sure the HDDs available in the server are listed here.
10. Press Tab to place cursor in the HDD and select space bar in the keyboard to select the drives. Make sure the HDDs are checked. Checked HDDs appear “X” as shown below.
11. Give a name to this configuration. VD0 and select Ok.
12. Now you will be taken back to the main screen
13. Now we need to initialize the disk
14. Fast initialization is selected
15. Now goto next page by pressing Ctrl + N
16. Again press Ctrl + N
17. Press Ctrl + N and you will be taken to the main screen
18. Press ESC
19. To reboot, in the Menu -> Marcos -> Select Ctrl + alt + delete
HP iLo configuration (iLO – Integrated Lights-out)
Restart HP server -> Press F8 to load iLO configuration
Configuring iLO is straight forward, just goto Network settings and uncheck DHCP and enter static IP address.