DELL R900 Server RAID Array configuration details _ server other

The disk array can be generated before or after the system is installed, which is considered a (large) hard drive with fault tolerance and redundancy. The disk array can not only join a ready-made system, it can support capacity expansion, the method is very simple, only need to join a new hard drive and execute some simple instructions, the system can take advantage of this new capacity in real time.

· types and Applications of RAID

The IDE and SCSI are two different interfaces for computers, which are commonly used in PCs, which are typically used for servers. Based on these two interfaces, raid is divided into two types: RAID applications based on IDE interfaces, called IDE raid, and SCSI-based RAID applications called SCSI raid.

Depending on the architecture, RAID can be divided into:
Software RAID (software RAID)
Hardware RAID (Hardware RAID)
External raid (External RAID)

• Software RAID is already included in the system in many cases and becomes one of the features, such as Windows, NetWare, and Linux. All operations in software RAID are handled by the central processing Unit, so the utilization of system resources can be very high, thus reducing the performance of systems. Software RAID is not required to add any additional hardware devices, because it relies on your system-primarily the CPU's functionality-to provide all available resources.

• Hardware RAID is usually a PCI card, and you will see the processor and memory on the card. Because the processor on this card can already provide all the necessary resources for raid, it will not consume system resources, so that the performance of the system can be greatly improved. Hardware RAID can be connected to a built-in hard drive, a hot-swappable backplane, or an external storage device. Regardless of which hard drive is connected, control is on the raid card, which is controlled by the system. In the system, hardware RAID PCI cards usually require an Android driver or the system will refuse support.

• External raid is also a part of hardware RAID, except that the RAID card is not installed in the system, but is installed on the external storage device. This external storage device is connected to the SCSI card of the system. The system does not have any RAID capabilities because it has only one SCSI card; All RAID features will be moved to this external storage. The advantage is that external storage can often connect to more hard disks and will not be affected by the size of the system chassis. Some advanced technologies, such as dual-computer fault tolerance, require multiple servers to be connected to an external storage to provide fault-tolerant capabilities.

· Configuring a RAID disk array

Why do you want to create a logical disk?
When the hard drive is connected to the array card (RAID), the operating system will not see the physical hard drive directly, so you need to create a logical disk (also called a container) that is set to raid0,1 and 5 so that the system can recognize it correctly.
Logical disks (Logic Drive), Containers (Container), or virtual disks (fictitious Drive) all mean one thing, they are just different names for different array card producers.
Second, how to create a logical disk
Use the configuration tool of the array card itself, the BIOS of the array card. (generally used to reload the system or do not install the operating system to create a container (Adaptec array card)/logical drive (Ami/lsi array card).
Use the Configuration tool software provided by the third party to implement the management of the card. such as Dell Array Manager. (These software is used on the server already has the operating system installed)
Third, correctly identify the model of your array card (in this case, Dell, in fact, are similar)
Identify your disk array controller (disk array controller is optional and can be omitted if no disk array controller is purchased)

If you have a Adaptec disk array controller (PERC 2,perc2/si,perc3/si,perc3/di), you will see the following information when the system posts:
Dell PowerEdge Expandable RAID Controller 3/di, BIOS v2.7-x [build xxxx] (c) 1998-2002 Adaptec, Inc. All Rights Reserved. <<< Press CTRL + A for Configuration utility! >>>

If you have a AMI/LSI disk array controller (PERC2/SC,PERC2/DC,PERC3/SC,PERC3/DC, Perc4/di, PERC4/DC), you will see the following information when the system posts:
Dell PowerEdge Expandable RAID Controller BIOS x.xx June 26.2001 Copyright (C) American Megatrends Inc.
Press Ctrl+m to Run Configuration Utility or press ctrl+h for Webbios

Or:

The PowerEdge expandable RAID Controller BIOS x.xx Feb 03,2003 Copyright (C) LSI Logic Corp.
Press Ctrl+m to Run Configuration Utility or press ctrl+h for Webbios

Name Explanation:
Disk Group: A set of disks, which is equivalent to an array, such as configuring a RAID5, which is a disk group
VD: Virtual disk, Virtual disk can not use the full capacity of the array, which means that a disk group can be divided into multiple VD
PD (Physical Disk): physical disks
Hs:hot Spare Hot Standby
MGMT: Management

"One", creating logical Disks
1, according to the virtual Disk Manager at the bottom of the screen prompts, in the VD Mgmt menu (you can switch menus through ctrl+p/ctrl+n), press F2 to expand the Virtual Disk creation menu

2, in the virtual disk to create a window, press ENTER to select "Create New VD" creation of virtual disk

3, in the RAID level option to press ENTER, you can support the RAID levels, the RAID card can support the level of raid0/1/5/10/50, depending on the number of specific configuration of the hard disk, this location may appear the options will be different.
Choose a different level, and the options will vary. Select the RAID level you want to configure (we take RAID5 here for example) and press ENTER to confirm.

4, confirm the raid level, press the DOWN ARROW keys, move the cursor to the physical disks list, move up and down to the desired hard disk location, press the space bar to select (remove) the hard disk in the list, when the number of selected hard disk to achieve this RAID level requirements, Basic The default capacity information for this raid can be displayed in the VD size of the settings. There is a hard drive with x marked as selected.
By pressing the TAB key after you have selected the hard drive, you can move the cursor to the VD size bar, and VD size can be set manually, that is, you can not configure all the capacity on a virtual disk. If this virtual disk does not use all of the capacity of the RAID5 array we have configured, the remaining space can be configured as another virtual disk, but the next virtual disk must be configured to return to VD Mgmt Creation (refer to step 13th for detailed instructions). The VD name is set as needed, or it can be empty.
Note: The minimum number of hard drives required for each RAID level, raid0=1 raid1=2 raid5=3 raid10=4 raid50=6

5, modify the Advanced settings, select the VD size, you can press the DOWN ARROW key, or the TAB key, move the cursor to the advanced settings, press the space bar to open (disabled) advanced settings. If it is turned on (the red box has an X mark turned on), you can modify the stripe Element size, and the read Policy and write policy,initialize of the array can choose whether to initialize at the same time as the array configuration.
Advanced settings are turned off by default (not modifiable) and it is recommended that you do not modify the settings here if there are no special requirements.

6, the above configuration confirmation is complete, press the TAB key, move the cursor to OK, press ENTER, the following prompts, if it is a new array, recommend initialization, if the purpose of configuring the array is to restore the previous data, do not initialize. Press ENTER to confirm and continue.

7, after the configuration is complete, will return to the VD Mgmt main interface, move the cursor to virtual Disk 0 in the figure, press ENTER.

8, you can see just configured the success of the virtual disk information, see the completion of the ESC key can return to the main interface

9. In this interface, move the cursor to Virtual Disk 0 in the diagram, press F2 to expand the menu for the operation of the dummy disks.
Note: The left has the + flag, move the cursor here, press the RIGHT ARROW key, you can expand the submenu, press LEFT ARROW key, you can close the submenu

10, as shown in the red box below, you can initialize the virtual disk that was successfully configured (initialization), consistency check (consistency check), delete, view properties, and so on.

11, if we want to initialize this virtual disk, you can move the cursor to initialization place, enter after the start Init. The prompt window pops up, initialization clears all data, and if you are sure you want to initialize, press ENTER at OK to continue.
Note: Initialization clears all information from the hard drive, the array, and cannot be recovered

12, after the confirmation can see the progress of initialization, the left red box as a percentage, the right red box to represent the current operation. Wait for initialization to be 100%, and the virtual disk configuration is complete.

13, if you just configure the virtual disk does not use the full capacity of the array, the remaining capacity can be divided here to use. Move the cursor to the space allocation, and press the right ARROW key to expand this menu

14. Move the cursor to the *free space*, press the F2 key to step 15th, or press ENTER directly to step 16th

15, in the pop-up add New VD Press ENTER.

16, again into the configuration of the virtual disk interface, at this time the left red box for just configured the virtual disk has been selected for the physical disk information, the right red box can choose this time to divide the capacity of space. Again, if you don't divide it all, you can return to step 13th again to create a virtual disk.
Note: Because the virtual disk was built based on the array you just created, the raid level is the same as the one you just created and cannot be changed.

17. Each time you create, you add a new virtual disk to the dummy disks. These virtual disks are all partitioned on the same disk group (the RAID5 we just configured).

"Two", Configuration hot-standby (hot spare)
There are two modes of configuring hot spare, one is global thermal standby, this means that the hot spare hard disk can be used as a hot standby for all the arrays on this channel, and the other is independent hot standby, which configures the hard drive to warm up all the virtual disks in a specified set of disks, that is, other arrays outside this disk group, even if the hard drive falls off, This hot standby is not going to automatically do rebuild.
Configure Global Hot Standby:
1, first to have the existence of the disk group (array), our example here is that two arrays have been configured, array 0 is RAID5 by 0, 1, 23 Physical disk configurations, and array 1 is RAID1 by 4, 52 physical disk configurations, as shown in the figure:

2, press CTRL + N switch to the PD mgmt interface, you can see the status of the 4th hard drive is ready.

3, move the cursor to the 4th hard drive, press F2, in the pop-up menu, select Make Global HS, configure the global hot spare

4, confirmed, the status of the hard drive 4th into Hotspare

5, after the configuration is complete, you can see that disk group 0 and disk Group 1 hot spares are the same.

6, remove hot spare, enter the PD Mgmt menu, move the cursor to the Heat reserve, press F2, select Remove Hot Spare, return to remove

To configure an independent hot standby:
1, in the configuration of the virtual Disk Management interface, the cursor to the need to configure independent hot standby on the disk group, press F2 Key, in the menu appears to select Manage Ded. Hs

2. Move the cursor to a hard disk that needs to be configured as hot spare, press the SPACEBAR and see the X logo, indicating that the hard drive is selected. Move the cursor to OK to enter, complete the configuration

3, you can see that disk group 0 already has a hot spare, and is dedicated. Disk Group 1 does not have a hot spare.

4, remove hot spare, with the 1th step, move the cursor to need to remove hot spare disk group, press F2 Key, in the menu that appears select Manage Ded. Hs

5. Move the cursor to the hot spare hard drive that needs to be removed, press the SPACEBAR, and remove the X logo, indicating that the hard drive has been removed. Move the cursor to OK to enter and complete the hot standby removal.

"Three" delete virtual disks:
1, move the cursor to the virtual disk to be deleted, press F2, select Delete VD press ENTER to continue

2, in the pop-up confirmation window, OK place press ENTER to confirm can delete.
Note: Deleting this virtual disk will remove all the data.

3. Delete the disk group, move the cursor to the disk group you want to delete, press F2, select Delete disc Group press ENTER to continue

4, in the pop-up confirmation window, OK place press ENTER to confirm, can delete
Note: The deletion will delete all the data for this disk group.