How to do soft RAID implementation under Linux

RAID is also hard and soft? Yes. RAID does have a distinction between software and hardware, the two are relative, software (piece) RAID refers to the RAID that does not use the hardware RAID card or the motherboard integrated RAID function to achieve RAID, is to achieve this purpose at the operating system level; Hardware (piece) RAID refers to the implementation of RAID through RAID cards or integrated RAID functions on the motherboard, which is achieved at the lower level of the operating system, and the operating system is almost unaware of this situation.

After understanding the differences in hardware and software designs, we can analyze issues such as input cost, performance, reliability, and scope of application according to the differences in their structure.

1.In terms of input costs, the investment in hardware RAID is obviously higher than the investment in software RAID, generally speaking, in terms of investment, independent RAID card "motherboard integrated RAID function module" software RAID, of course, the existence of these different RAID architectures are reasonable, there is no one is the best, under different needs, only the most suitable RAID architecture.

2.The difference in input cost can reflect the performance to a large extent, and the performance of RAID card (or functional module) is one of the important factors that determine the best product. In general, the performance of the independent RAID card is the best, and the independent RAID card itself comes with a data buffer and a data operation module, which can greatly speed up the reading and writing speed of data in the RAID; The RAID function module integrated by the motherboard is generally worse than the standalone RAID card in terms of performance, and the function is relatively simple; Software RAID generally depends on the operating system, and the use of software RAID will increase the burden of the operating system, in the absence of an independent RAID management module, the operating system virtual RAID related operations can only be responsible for the operating system itself.

3.In terms of reliability, of course, the software RAID is the worst, the RAID function module integrated by the motherboard is in the middle, and the independent RAID card is generally more stable.

4.If the user is just a RAID enthusiast who just wants to understand the structure of RAID and its related aspects, and does not need to store particularly important data, then software RAID is the first choice, the main reason is that the investment cost of this form of RAID is almost zero; If the user needs to store relatively important data, and has certain requirements for the performance and reliability of RAID, but the cost should be as small as possible, then the RAID function module integrated by the motherboard can be selected as a reference; If the data stored by the user is critical business data or has high requirements for RAID performance, then you must choose hardware RAID to implement it.

I don't know, I'm on a mission.

In Disk Management, the status of the failed volume will show as Failed Redundancy, and one of the disks will show as Offline, Missing, or Online Error. You can recover a mirrored volume by doing the following:

Make sure that the disk is connected to your computer and that it is powered on.

In Disk Management, right-click the disk that is identified as Offline, Missing, or Online Error, and then click the Reactivate Disk option on the shortcut menu. The state of the disk should return to Good, and the mirrored volume should be automatically rebuilt.

If the disk is severely damaged or cannot be repaired, you will only see the "Delete" command in the shortcut menu that pops up, and Windows 2003 will no longer be able to repair the mirrored volume. In addition, if a disk continuously displays "Online Errors", it may indicate that the disk is about to fail and should be replaced as quickly as possible. If the mirrored disk fails to be reactivated after repair, or if the state of the mirrored volume does not return to the Good state, you must replace the failed disk and create a new mirrored volume.

Right-click on the failed volume and select the Delete Mirror option, and the Delete Mirror dialog box is displayed.

Select the missing disk from the list of disks and click the Delete Image button, a Disk Management warning box will be displayed to prompt the user for confirmation.

Click the Yes button and the mirrored volume will be deleted. Then right-click on the lost disk and select the "Delete Disk" option from the pop-up shortcut menu to delete the disk.

Replace the disk with a new one and set the disk to dynamic.

Create a new mirrored volume. For details about how to create a mirrored volume, see "Adding a Mirrored Volume" in the preceding section. Replace the failed disk and set it to dynamic.

In Disk Management, right-click the RAID5 volume of the failed disk and select the Recover Volume option from the shortcut menu that pops up, and the Repair RAID-5 Volume dialog box is displayed.

Select the disk you want to replace the failed disk in the RAID5 volume and click the OK button. At this point, the RAID5 volume starts to be repaired automatically.

Right-click the failed disk and select the "Delete Disk" option from the pop-up shortcut menu and delete the disk from the system.