What is the price of RAID data recovery for RAID card corruption

The information stored and processed by the server RAID itself is very complex, and the professional and technical type is relatively strong, so it is best not to deal with it if you are not a professional. Generally speaking, if the server RAID card is damaged, it will not have a great impact on the data stored inside, so the data inside can still be recovered. The reason why it can be recovered is because RAID stores the data and the corresponding parity information on each disk that makes up the RAID, and the parity information and the corresponding data are stored on different disks, in which the complete data is stored on any N-1 disk, that is to say, there is a space equivalent to the capacity of a disk for storing parity information.

Therefore, when a RAID disk is damaged, it will not affect the integrity of the data, which is conducive to the complete recovery of the data.

Therefore, after the RAID card is damaged, you should find a professional to deal with it as soon as possible, and do not solve it by yourself to prevent complete data loss. As for the cost of restoration, it mainly depends on the specific problem, which is generally about 1,000 yuan. Of course, if some levels are high and complex, tens of thousands of yuan are possible, and the key specific problems are analyzed on a case-by-case basis.

RAID data recovery** is based on the specific data loss situation, and different situations** are different. If you don't have relevant experience, it's best to choose a professional for recovery, and you can contact a more formal data recovery company for consultation.

RAID5 is striped, for a 3-disk RAID5, two disks in a stripe provide data blocks D1 and D2, and the other disk provides check block P.

When the user writes data D1 and D2, p is XOR computed from D1 and D2. p = d1 xor d2。

For example, if the disk where d1 is located is damaged, the data of d1 can be calculated from the XOR of p and d2 (d1 = p xor d2).

Therefore, raid5 can only allow one disk to be damaged, and 2 pieces cannot be recovered, while raid6 can recover 2 blocks.

RAID5 stores the data and the corresponding parity information on each disk that makes up RAID5, and the parity information and the corresponding data are stored on different disks, in which the complete data is stored on any N-1 disk, that is, there is a space equivalent to the capacity of a disk for storing parity information.

Analyze data direction, start sector, stripe size, left and right structure, reorganize the disk and recover data!

If the replacement RAID card is the same as the original card specification and model, there will be no problem.

If the specifications and models of the two cards are different, you need to reinstall the new card driver. At this time, there will be uncertain possibilities, such as when the drivers are not very different, the RAID disk combination order is normal, and the original data of the hard disk can be read and written correctly; If the driver structure is very different, read and write errors may occur. Therefore, try to choose products with the same specifications as the original card to ensure data security.

RAID information can be stored on a RAID card, but it needs to be supported by a card (the kind with a battery cannot be stored if it doesn't). When you replace a new RAID card, connect the hard drive, and for the first time, you will be prompted to read the RAID information from the hard drive. It's okay to choose yes, pay attention to every step when doing it, and don't do the wrong operation.

Otherwise trouble!

Use the same model of RAID card, otherwise the RAID information will disappear and the data will disappear! The best thing to do is to find a card of the same model.

This is a premise, if your RAID is RAID1, this information can be seen, and the card is broken and the same card data will not be lost. But if it's a raid5, you'll have to find a card of the same model for your data. When you connect the hard drive, you will be prompted that you need to read the RAID information from the hard drive, and you can import it when you select it.

This must be chosen correctly, otherwise it will be very troublesome later. RAID data can also be recovered, but it is too expensive. If the server is IBM, you can contact directly

0755-83766668 IBM Server Core Reseller.

As long as the settings are the same as before, the sockets are the same as before, and the data is still there!

RAID 5 allows you to damage one disk without losing data, so as long as you recover the latest data, the data can be fully recovered.

RAID5 data recovery method

1.First connect the SCSI hard drive cabinet directly to the SCSI expansion card without RAID capability, and then connect all the hard disks of the server array to a single hard drive on a dedicated (modified Windows 2003) repair platform.

2.In order to protect the original data of RAID 5 and avoid altering the original data due to data recovery operations, all hard drives must be read-only full mirrored during all data recovery processes, and the image must be stored on a device with redundant protection.

3.Analyze the dual-cycle check parameters of the original RAID from the image file to build a virtual RAID platform.

4.Unplug the offline hard disk from the virtual RAID platform and explain the file system. At this point, you can export RAID data.

5.Connect the disk cabinet on the server where RAID 5 resides and reconfigure the RAID. Finally, all data is transferred back to the newly created RAID array through network DD, NFS, SAMBA, FTP, SSH, and other data transmission modes.

RAID information is lost in a large proportion of data disasters in disk array environments, and many engineers have had the experience of rebuilding RAID according to the original RAID structure, and the data will be recovered. Is this possible?

Answer: There are several ways to rebuild a RAID (RAID meta information), create only RAID information (RAID meta information), regenerate the check when creating a RAID (only do synchronization), and fill initialization when creating a RAID If the rebuilt structure is different from the original structure (involving controller firmware, RAID level, block size, verification mode, and disk sequence), the rebuilt RAID logical driver must be different from the original, so that the file system structure will be damaged and data loss will be caused by rushing to load the file system.

The following assumptions assume that the rebuilt structure is the same as the original structure: If the controller rebuilds only the RAID information, it depends on whether the previous RAID structure is normal or degraded, if it is downgraded (the existing hard disk is offline), after the reconstruction, because the data is composed of new data and part of the old data, the file system will be destroyed and irreversibly recovered. If the previous RAID structure is intact, rebuilding the RAID will not affect the data, and the original data can be restored completely intact.

If the controller is rebuilt by creating a RAID rebuild check (even in the background), as in the case above, if the hard disk has been offline before, such a rebuild will break the consistency of the data. If the previous RAID state is online (good), then such a rebuild will not affect the data. If the controller's rebuild method is to fill the data rebuild (usually clear zero), then the data will be corrupted anyway.

In this way, the premise that rebuilding RAID can recover data when RAID is damaged is that the controller is designed not to destroy data, and the previous RAID state is good, and the rebuilt structure is exactly the same as the original one. Any other rebuild has data risks.