Knowing this information, you will know when the file fails, what can we do in a virtualized system ESXi5.0 of?

[ESXi5 virtualization system scenarios Overview]
storage mode the user is achieved by FC SAN iSCSI functionality mode. DELL server to do while taking advantage of the physical storage infrastructure, the use of FreeNAS to implement iSCSI. And additionally do ESXi5.0 by two DELL server virtualization system.
1, FreeNAS layer UFS2 file system that stores the entire file to build a sparse mode, mount the ESXi5.0 system.
2, 6 running ESXi virtual machines within the system, which has three of the most important.
3, the first windows2003 system virtual machine is this company in the local portal.
Hybrid structure type: ASP.net and PHP
database type: SqlServer2005 and Mysql 5.1.
4, a second FreeBSD system, run Mysql database for other multiple virtual machines to use.
5, a third windows2003 servers, storage newly developed code.
[ESXi5 virtualization system failure Use the
staff found ESXi system can not connect storage, through subsequent investigation found that in the FreeNAS UFS2 file system fails the inspection, then the file system repair with fsck. After the repair ESXi system can be connected to memory, but ESXi system fails to identify the original data storage and VMFS file system, VMFS formatted after the staff found no data.
[ESXi5 virtualization system data recovery procedure]
1, FreeNAS file system --- application framework level:
FreeNAS (UFS2 File System -> File a large sparse mode) -> ESXi 5.0 (VMFS file system layer) -> Single virtual machine's virtual disk (windows-NTFS file system / FreeBSD-UFS2 file system).
2, FreeNAS file system - analysis of storage:
mirrored FreeNAS layer, storage analysis, we can find a more than 900 GB of large files, the file name: iscsidata1. UFS2 binary configuration file system to locate the data iscsidata1 Inode file, the file found signs reconstructed, the amount of data in the inode pointer little. FreeNAS layer can not be resolved, you can not enter into the analysis phase VMFS layer.
Important structural collection UFS2 file system:
Block Size: 16KB
Segment Size: 2KB
cylinder group size: 188 176 KB
UFS2 a data pointer occupies 8 bytes, one block can store data pointer 2048. Then a two pointer blocks may be stored: 2048 2048 16KB = 64GB of data. A three pointer blocks may be stored 64GB * 2048 = 128TB data. If you can find three pointer blocks iscsidata1 file will be able to solve the problem FreeNAS layer. However iscsidata1 reconstructed document, and processes and size as the original, estimated some pointer blocks has been covered. Inode inode and the new iscsidata1 file's original iscsidata1 file in a location, try searching, no other useful inode appear. The scene had to write a program to collect useful pointer blocks:

Since the file is to use a sparse mode iscsidata1, relaxed collection condition only collected a large number of three pointer blocks and two pointer blocks. After all three pointer blocks collected for analysis, are invalid, three pointer blocks used without iscsidata1 file, new estimates are covered in the new iscsidata1 file (file in the new mount ESXi5.0 iscsidata1 there VMFS formatting process, the use ESXi5.0 GPT partitions, partition will GPT GPT partition table information and header data written into the redundancy of the final disk, it will use three iscsidata1 file pointer blocks).
Analysis of two pointer blocks can now collected on a large number of data points to two pointer blocks is the DUMP, then positioning data from the disk to the secondary pointer. A large amount of data thus obtained DUMP.
3, FreeNAS file system - begin to analyze VMFS layer:
Heavy VMFS formatted, and a pointer to the original UFS2 has been lost, causing VMFS Metafile has been largely unavailable, no important reference information, but fortunately no virtual machine snapshots, still recoverable. (File System Structure windows (NTFS) and FreeBSD (UFS2) system) by a single virtual machine layer, is positioned up to VMFS layer, a single layer 64GB files VMFS targeting DUMP out by a plurality of times, the final three Taiwan important virtual disk virtual machines have been restored. Upload the recovered data pages and database data to a new system built in, pull up applications, data, no problem.

[ESXi5 virtualized system recovery results]
by user acceptance, data is correct, so far data recovery end of the work.