Minicomputer data recovery technology: IBM AIX JFS2 file system deletion
Minicomputer data recovery technology: IBM AIX JFS2 file system deletion
We know that the storage systems and backup systems of large enterprises and institutions are relatively complete, especially the business systems of enterprises, and the emergency plans in all aspects are very perfect. However, if there is a problem due to human error or the device itself, this situation is a small probability event, but for the core data, it will be a disaster. The data recovery of these business systems will be the last straw. Let's take a look at the recent data recovery case of a Unix IBM AIX5.0 JFS2 file system in an insurance group in Beijing. The Unix Data Recovery Expert at Darth Data Recovery Center uncovers the solution for accidental deletion of the IBM AIX JFS2 file system.
IBM AIX JFS2 file system data recovery technology Darth Technology is stronger
The administrator deletes the core business data through overtime and misuse, and makes a big mistake.
Hardware environment: IBM minicomputer, IBM DS4300 storage disk array
Operating system: IBM AIX5.0
File System: JFS2
Event Description: The administrator worked overtime overnight, about 3 o'clock in the morning, the ghost made the rm * command, and deleted the oracle database file, control file, log file, and so on.
Under normal circumstances, before executing the rm * command on the minicomputer, you should first execute pwd (print working directory) to view the current directory, then ls view the list of files and directories in the current directory, and then delete it after confirming the error, but management The staff was obviously too tired and did not think about it and performed the deletion.
Then, the administrator found that the file was deleted by mistake. Since the event was too important, the company was notified immediately and contacted with the ibm for sale. The responsible manager worked with the Darth Data Recovery Center, so he also dialed the 24-hour hotline, Das Data Recovery Center. The night emergency service engineer answered the call. According to the advice of the Darth data recovery emergency engineer, do not write any file to this file system. The file system is 200GB in size. Immediately open a 200G partition and put this file system dd. Go to this partition and then down to the mobile hard drive for data recovery.
IBM expert home data recovery failed for 3 days, Darth expert 3 hours data recovery 100% success
After the ibm technical support contacted by the administrator, the company arrived at the scene around 10:00 the next day. The customer requested that the Darth data recovery expert be on standby at the scene. The data recovery operation was first performed by the ibm engineer. IBM senior engineers perform original data recovery operations in a small machine environment and communicate with ibm second-line engineers from time to time. In fact, the data recovery progress of ibm senior engineers is not smooth. Since 22 customers need to recover in total, ibm senior engineers have only recovered 7 files after 3 days of hard work. In the oracle data file detection, there are The content of a file is incorrect. Since the data recovery rate did not meet the customer's requirements, the data recovery failed.
At this point, the Dass Data Recovery Engineer, who was on standby at the customer site for 3 days, began to look at the 200G image file that was originally requested by the administrator. The Das Data Recovery Expert spent a total of 3 hours and recovered 22 of all customer needs. Instance, the restored oracle instance file is copied to the original AIX system environment, start oracle, everything is normal. The hearts of the engineers who worked overtime in the engine room for a few nights and nights finally relaxed.
Ibm senior engineer asked Das data recovery experts how to recover? In fact, this is not the temporary rescue of the Darth Data Recovery Center, but the accumulation of data recovery for the IBM AIX JFS2 file system that has been accumulated for many years. Dashing JFS2 data recovery software D-Recovery for IBM JFS2 has made a great contribution! This data recovery software developed for IBM minicomputer has not been publicly sold, but it is quite large in the data recovery industry. Fame, it should be said that IBM small machine data recovery tool!
Minicomputer RAID Data Recovery Technology: File System Data Recovery Technology under UNIX System
1. In the UINX file system of minicomputers, all data files and directories and attributes are described by inodes. Inodes should be said to be the soul of management data files and directories. In the JFS2 file system, the inode size usually takes 512 bytes. The inode contains important information: inode number, file or directory size, file attributes (permissions, etc.), four times (last data accessed, last status changed, Last data modified, created), data pointer, inode connection number, and so on.
2. According to the JFS2 file system architecture, all inodes of a file system are similar to ordinary files. When space is allocated according to requirements, when we do data recovery, we need to extract all inode information of the file system and save it as a file, as needed. Analyze this file.
3. In the IBM AIX JFS2 file system, when a file or directory is deleted, the file or directory name is not changed, and the inode information of the file does not change very much. Usually, the time is updated and the number of inode connections is updated to 0 (inode connection number refers to how many files share this inode, an inode can be used for multiple files, but a file can only correspond to one inode), other information generally does not change, the most important of which is that the data pointer does not Change, this will have the possibility to recover after deleting the file.
Darth Data Recovery Expert Tips:
However, when data is lost due to various reasons under the UNIX system, you must immediately disconnect the server from the terminal and stop any write operations, including uploading terminal data to the server. And as soon as possible, the original file system data is dd backup, and then contact the Darth Data Recovery Center for the first time to perform data recovery operations on the mirror backup.
Let's introduce a data recovery software developed by Darth Technology for Windows. DAS Data Recovery Software Standard Edition D-Recovery Standard is developed by domestic well-known software company Darth Technology for Windows operating system FAT (12/16/32 ) / NTFS file system design of a professional data recovery software, let's take a look at the other features of this software.
First, the hard disk partition lost data recovery:
Supported partition failure types:
After Ghost reinstalls the system, the partitions are merged;
The number of partitions changes after Ghost backup;
Delete partitions by mistake (delete all partitions or delete individual partitions);
Data loss after repartitioning;
After the one-key restore of the notebook computer, multiple partitions become a large partition and so on.
Scan for lost partitions: without overwriting, you can scan for lost partitions and recover partitions;
Partition table backup: back up the disk partition table information of the current state. When the partition is damaged or lost, it is convenient to restore to the current state;
Partition table recovery: restore the status when backing up with the partition table information backed up in advance;
Partition table reconstruction: Scan the partition, select the correct partition and rebuild the partition table to restore the partition.
Second, the commonly used data recovery function
Applicable to data recovery failures: data loss due to accidental deletion, misformatting, file system corruption, misinstallation of the system, Ghost partitioning, and partition coverage.
Full scan: mainly used for file system corruption, scan loss of partition failure, and other data recovery effects are not good, full scan can fictitate partition information and improve the success rate of data recovery;
Partition scan: mainly used for partition data deletion, partitioned file system can not be opened, partition prompt format, partition formatted, etc., use partition scan to recover data.
Third, the Darth data recovery software standard version is expensive?
Not expensive, because you can try it for free, which means that users can see the data first, then register to buy, so there is no risk. For temporary data recovery users, you only need to register for the 24-hour version, you only need 99 yuan, support WeChat, Alipay payment, 10 seconds to get the activation code, is it very cost-effective? http: //Click on the download to try it out?
About Das Data Recovery and Forensics Center
Dasi Technology, a national high-tech enterprise, the only collaboration unit for the data recovery of the confidentiality of the Tianjin State Secrecy Bureau, the National Secrecy Bureau commonly used office equipment storage component sensitive information inspection system project project undertaker, the famous brand of data recovery and forensics industry, The leading data recovery technology in China and even in Asia! The full name of Darth Technology is Dash Kerry Technology (Beijing) Co., Ltd., which was established in August 2007 with a registered capital of 15 million yuan. Dasi Technology is a state-level high-tech enterprise with data recovery and forensics technology as its core. The company has more than 30 data recovery and forensics software with independent intellectual property rights. The company has a research and development center, a data recovery and forensics service department, and a server RAID data recovery emergency center.
Pay attention to the Darth WeChat service number or subscription number for more information:
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