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RAID - 520 Block Sizes 520 Clone Data can be corrupted as it is read back to the host. Furthermore, latent disk errors can corrupt data while it is sitting on the disk doing nothing. EMC systems use sector-level protection (sector checksum) to protect against these problems. Safeguards against data corruption are embedded in every sector of Dell|EMC data. When disks are formatted, they are divided into a series of data blocks or sectors. The standard size for a data sector is 512 bytes, but Dell|EMC products are formatted into 520 byte sectors: 512 bytes of user data plus 8 bytes of validation data. Part of the validation area contains a time stamp, a write stamp, and a shed stamp that are used to ensure parity consistency. It is a significant advantage for device users, but it makes it much more difficult for data recovery companies to recover the files when the RAID system has failed.  Due to the sector/block size of EMC devices, using any applications based on Windows/Linux OS to rebuild the RAID becomes impossible. Therefore, we designed a Windows based software that we call ‘520 clone’ to convert the sectors back to 512 bytes from 520bytes. The software supports ATA/SATA/SCSI/FC/SAS hard disks drives and has three cloning/converting modes: 512 to 512, 520 to 512 and 522 to 512. It has an average cloning/converting speed of 45MB per second when running in 520 to 512 mode. After converting the hard drives using this application, they can be mounted under Windows/Linux OS for further data recovery. |
