Shulou(Shulou.com)06/02 Report--

Disk array two hard disks offline data recovery case 1:

Customers use Dell 2850 server to build a raid5 disk array, which contains 6 hard disks (SCSI hard disk, single disk capacity 300G), and the server operating system is linux Redhat4; file system and ext3 file system. The server was paralyzed in the process of use, and the administrator checked the array and found that two hard drives were offline and one of them was forced to go online, but the operating system started abnormally. At this time, the administrator realized the seriousness of the matter, immediately shut down the server, and then contacted the data recovery center for data recovery.

Conclusion of initial inspection of data recovery center:

In the server data recovery work, it is very common for two raid5 hard drives to go offline. Because the raid5 disk array supports the honor protection of one hard disk offline, once multiple hard drives are offline, the server will be paralyzed and will not go online automatically. As the raid controller has a certain surface sensitivity, most of the hard disk drop is closely due to power fluctuations, controller bug and other random reasons, so the disconnect disk may not have serious physical failure. This is the case. But at this time, the risk of forced online operation by the administrator is very great, once the online error will cause the controller to produce some irreversible damage to the data, and when the administrator enters the operating system, it will be repaired because the file system is inconsistent, all the hard disk data in the server is inconsistent, and the data recovery is very difficult.

Server data recovery process:

First of all, make a full backup of all the hard drives in the server, and during the backup process, it is found that several hard drives have bad paths but are not offline, because raid did not read the bad paths of the hard drives. After the backup is completed, the raid structure of the original server is analyzed, and then the raid environment is simulated to verify the raid structure malformation. the structure destroyed in the later stage of the server is manually modified, and the modified data is exported to an intermediate storage for temporary storage. The last step of data recovery is to use the intact hard disk to build a new raid5 disk array on the server and migrate the recovered data to the new raid. Verify that all the recovered data is normal and the data is recovered successfully.

Server data recovery conclusion:

Once multiple hard drives are offline and the server is paralyzed in the raid5 disk array, don't force the online operation blindly. If there is enough spare space, you can mirror all the source hard drives. There are two ways (under WINDOWS2003 or DOS, other operating systems are at risk):

The hard disk that is the same or larger than the capacity of the source disk can be used as the target disk and all sectors of the source disk can be CLONE to the target disk. Do the same operation on all disks.

1. Each source disk can be completely sector-based output files to some mass storage space (such as high-capacity hard disk, NAS, SAN, DAS, etc.)

Disk array two hard disks offline data recovery case 2:

The malfunction of HP LH6000 is as follows: one hard disk is flashing red light, the machine is still running normally, but it is not long before the system is not working properly, then it is found that the red light of another hard disk is also flashing.

Disk array data recovery process:

1. Start the server and press Ctrl+M to enter the NetRaid hypervisor when self-testing to the array. Check the array information and find that the status of the hard disk is Failed, and use the modified configuration to forcibly set a hard disk to OnLine. Restart the server, which is invalid during the hardware self-test before entering the system and failed to start.

two。 Start the server and press Ctrl+M to enter the NetRaid hypervisor when self-testing to the array. Select the disk array, manually Fail the hard disk hanging from the original OnLine, and then manually set another Failed hard disk to OnLine, and restart the server to enter the system.

3. After checking that the system and database are running normally, the Array configuration tool manually sets the Failed hard disk to Rebuild,100% and then restarts the server, and all the arrays and systems are restored.

The author works on another server running ERP system (HP ProLiant language 370). Four 146GB hot-swappable hard drives are configured into a disk array with RAID level 5 through raid cards (Smart array array cards). One of the hard drives suddenly failed during operation. Server RAID 5 automatically enables hot backup hard drives (Hot Spare) to logically replace damaged hard drives. The data access task of the entire hard disk is still running intact in the original read-write program column, and the application and database are not affected.

Check the status of the hard drive through the ACU tool included with HP and find that the hard drive warned by the red light is offline. If two hard drives of Raid 5 in the HP ProLiant server show a red light, the system has crashed and the database cannot be accessed, but the system will not shut down automatically. When the second hard drive turns on the red light, the data can not be recovered by conventional means, so we can only pay to find a professional third-party data recovery company to recover the data.

Therefore, for HP's old HP LH6000 series servers, the design of the array is quite different from the current HP ProLiant series server array. As far as the operation method is concerned, the array operation method of the HP LH6000 server has many options, including the ability to delete the array and rebuild it after the array failure, and the initialization is also selected manually. However, the initialization of the HP ProLiant series server array is automatically performed in the background after configuring the array, so the ProLiant series servers cannot reconfigure the array after the array error.

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