RAID Tutorial Full graphics hands-on teaching you to do Raid_ server other

When it comes to disk arrays (raid,redundant array of independent disks), it is now almost one of the technologies that network administrators must master, especially small and medium-sized enterprises, because disk arrays are widely used and are one of the main scenarios for current data backup. However, many network administrators only in various media to see the relevant theoretical knowledge, but did not see some of the actual disk array configuration method, so still only a little knowledge, to their real configuration, but not the start. In this paper, a specific disk array configuration method for example to introduce some of the basic disk array configuration methods, give some key interface, so that you have a rational understanding of the configuration of the disk array. Of course, in order for you to have a more comprehensive introduction to the disk array, or to briefly review the theoretical knowledge of the disk array, so as to find a theoretical basis for the actual configuration.

One, the disk array realization Way

There are two ways that a disk array can be implemented, that is, "software arrays" and "hardware arrays."

A software array is the Disk management function provided by the network operating system itself to configure multiple hard disks on a connected common SCSI card into a logical disk to form an array. such as Microsoft Windows nt/2000 server/server 2003 and Netvoll of NetWare two operating systems can provide software array capabilities, where Windows nt/2000 server/server 2003 can provide raid 0, RAID 1, RAID 5;netware operating system can achieve RAID 1 features. The software array can provide data redundancy, but the performance of the disk subsystem will be reduced, some lower generation is still relatively large, up to 30%.

The hardware array is implemented using a dedicated disk array card, which is the object to be covered in this article. Today's non entry-level servers provide almost all of the disk array cards, either integrated on the motherboard or not integrated to easily achieve array capabilities. The hardware array can provide online capacity, dynamically modify array level, automatic data recovery, drive roaming, super high-speed buffering and other functions. It provides solutions for performance, data protection, reliability, availability, and manageability. The disk array card has a dedicated processor, such as Intel's I960 chip, hpt370a/372, Silicon Image sil3112a, and a dedicated memory for caching data. As a result, the server's operations on the disk are processed directly through the disk array card, so it does not require a large amount of CPU and system memory resources and does not degrade the performance of the disk subsystem. Array card-specific processing unit, which performs much better than conventional non-array hard drives and is more secure and stable.

Two, several disk array technology

RAID technology is an industry standard, and the definition of RAID level varies from vendor to manufacturer. The current definition of a RAID level can be widely recognized by the industry in 4 categories, RAID 0, RAID 1, Raid 0+1, and RAID 5.

RAID 0 is a storage space strip with no data redundancy, which has the characteristics of low cost, high reading and writing performance and higher storage space utilization, and is suitable for the special application of sound, video signal storage, temporary file dump and so on. However, because there is no data redundancy, its security is greatly reduced, the damage to any one of the disks that make up the array will bring disastrous data loss. In fact, there is no redundancy, no security, just improved disk read and write performance and the entire server's disk capacity. Generally only suitable for the small number of disk, disk easy to be scarce in the application environment, if the raid 0 configuration of more than 4 pieces of hard disk, for the general application is unwise.

RAID 1 is a complete mirror of two hard disk data, with good security, simple technology, easy management and good read and write performance. Because it is one by one corresponding, so it cannot be a single disk expansion, to expand, you must simultaneously on both sides of the mirror expansion of the same capacity. Because of this redundancy, the data space is wasted because of the fact that only half of the disk capacity is used for security purposes.

RAID 0+1 combines RAID 0 and RAID 1 features, independent disks configured as RAID 0, and two complete RAID 0 mirroring each other. It has excellent reading and writing performance, high security, but the cost of building arrays is large, the utilization of data space is low.

RAID 5 is currently the most widely used raid technology. Each piece of independent hard disk for striping, the same stripe area for parity (XOR), the calibration data evenly distributed on each hard disk. A RAID 5 array built with an n-block hard disk can have a n-1 block hard disk capacity, and storage space utilization is very high. Any loss of data on any hard drive can be calculated by validating the data. The biggest difference between this and RAID 3 is the fact that the data is evenly distributed across the hard drives. RAID 5 has the advantages of data security, fast reading and writing speed, high space utilization and wide application, but the disadvantage is that if 1 hard drives fail, the performance of the whole system will be greatly reduced.

RAID 1, RAID 0+1, RAID 5 array with hot-swappable (also known as heat-replaceable) technology enables online recovery of data, that is, when any one of the hard drives in the RAID array is damaged and no user shuts down or stops the application service, you can replace the failed hard drive, repair the system, recover the data, is of great importance to the implementation of highly available systems.

Three, disk array configuration instance

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, or 5 so that the system can recognize it correctly. Of course, logical disks (Logic Drive), Containers (Container), or virtual disks (fictitious Drive) all mean one thing, just different names for different array card producers. See the following configured servers with Dell Power Edge 7x0 series and Dell PowerEdge 1650 servers.

The configuration of the disk array is usually done using the BIOS tools of the disk array card, as well as the use of Third-party-provided configuration tool software to manage the card, such as Dell array Manager. This article describes how to use the array card's BIOS tool for disk array configuration in a Dell server.

If you are using a Adaptec disk array controller (PERC2, Perc2/si, Perc3/si, and Perc3/di) on your Dell server, you will see the following information at System Post:

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 your Dell server is configured with a AMI/LSI disk array controller (PERC2/SC, PERC2/DC, PERC3/SC, PERC3/DC, Perc4/di, and 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

The following two cases are described separately.

1. Create RAID (Container) on a Adaptec disk array controller

The steps to create a container on such an array card are as follows (note: Please back up the data on your server beforehand, the process of configuring the disk array will delete all data on the server hard disk!):

The 1th step is to first press the "CTRL + a" key combination when the system appears as a hint (Figure 1) during the self-test process. Enter the configuration program interface for the disk array card as shown in (Figure 2).

Figure I

Figure II

Step 2nd, then select "Container Configuration Utility" and enter the configuration interface as shown in (Figure 3).

Figure Three

Step 3rd, select the "Initialize Drivers" option to initialize the new or need to re-create the container's hard disk (note: The initial session of the hard drive will delete all the data on the current hard drive), press Enter and enter as shown in (Figure 4) the interface. The channel of the RAID card and the hard disk connected to the channel appear in this interface, using the "Insert" key to select the hard disk that needs to be initialized (refer to the tips at the bottom of the interface for specific use).

Figure Four

The 4th step, all choose to complete the required to join the array of disks, press the Add car key, the System key pop-up as (Figure 5) The warning prompt box. Prompt for initialization removes all data from the selected hard drive and interrupts all users who are using them.

Figure Five

Step 5th, press the "Y" key to confirm it, and enter the configuration main menu interface as shown in (Figure 6). After the hard disk is initialized, you can create a container for the appropriate array level (RAID1,RAID0, etc.), depending on your needs. Here we take RAID5 as an example to illustrate. Select the "Create container" option in the main menu interface.

Figure Six

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Step 6th, press ENTER to enter the configuration interface as shown in (Figure 7), with the Insert key to select the hard drive you want to use to create the container (container) to the list on the right. and press ENTER. In the configuration interface shown (Figure 8), select the RAID level by carriage return and enter the volume label and size of the container. All others remain the same by default. Then click Confirm on the Done button.

Figure Seven

Figure Eight

7th step, this is the system will appear as shown in (Figure 9), prompted to tell the user that when the created container has not been successfully completed "scrub (Clear)", the container is not redundant functionality.

Figure Nine

Step 8th, click Return to the main menu configuration interface shown in (Figure 6), select the Manage containers option, and click Enter to eject the current container configuration state, as shown in (Figure 10). Select the appropriate container to check the percentage of the "scrub" process in the Container Status option for this container. When it becomes "OK", the newly created container has a redundant function.

Figure 10

9th step, after the device is created, use the ESC key to exit the disk array configuration interface and restart the computer.

2. Create logical Drive (Logical Disk) on a AIM/LSI disk array controller

Note: Please back up the data on your server beforehand, the process of configuring the disk array will remove all the data on your hard drive! The entire disk array configuration process is similar to the method described above for creating a container on a Adaptec disk array controller. Specifically as follows:

Step 1th, in the post process, when prompted as shown in (Figure 11), press the "control+m" key combination to enter the RAID configuration interface as shown in (Figure 12).

Figure 11

Figure 12

2nd step, press any key to continue, continue to enter as shown in (Figure 13) The Management Main menu (Management menu) configuration interface. Select the Configure option, and then press ENTER to eject the Subordinate submenu, as shown in (Figure 14).

Figure 13

Figure 14

3rd step, if you need to reconfigure a raid, check "New Configuration", and if there is a logical disk that you can use, select "View/add Configuration" and press ENTER. Here, we introduce the new disk array as an example. Select the "New Configuration" option. When you press ENTER, a small dialog box pops up, as shown in (Figure 15).

Figure 15

Step 4th, select Yes and press ENTER to enter the configuration interface as shown in (Figure 16). Use the SPACEBAR to select the hard disk for which you want to create a logical disk, and when the last hard drive in that logical disk is selected, press ENTER.

Figure 16

5th step, if the array card type in your server is PERC4 DI/DC, you will see the configuration interface as shown in (Figure 17) after the carriage return, otherwise please go directly to step 7th.

Figure 17

6th, press the SPACEBAR to select the array bridging information, such as Span-1 (Bridging-1), appearing in the array box. You can create multiple arrays and then choose to bridge them.

Step 7th, press the "F10" key to configure the logical disk. Select the appropriate RAID type and the rest accept the default values. Select "Accept" and press ENTER to confirm that the final configuration information balloon shown in (Figure 18) is ejected.

Figure 18

Step 8th, the logical disk you just created needs to be initialized for use. Press the ESC key to return to the main menu shown in (Figure 13), select the "Initialize" option, and press ENTER to enter the initialization logical disk interface as shown in (Figure 19).

Figure 19

Step 9th, select the logical disk that you want to initialize, and press the space to eject a query dialog box, as shown in (Figure 20). Select Yes and press ENTER to eject the initialization process (note that initializing disk damage to the original data on the disk requires a good backup beforehand).

Figure 20

10th step, after initialization completes, press any key to continue, reboot system, RAID configuration completes.