Hardware-Options to increase system availability

SIMATIC Panel PC 677B with option: Dual hard disk drive 
The option “Dual hard disk drive” is the ideal solution for a periodic data and above all configuration backup solution via hard drive images. If the hard drive content is damaged or destroyed through operating errors, faulty software components or viruses, the functioning state of a hard drive can quickly and easily be restored via reconstruction without lengthy system downtimes.

Applications of the Hardware Option:

• Quick, easy Data Backup 
  By copying or applying conventional backup-restore routines, the data of the “work” drive is duplicated on the second “backup” drive. If, for example, an operating error damages the data on the work drive, it could quickly be restored from the backup drive.
• Backup of Hard Drive Partitions 
  With a hard drive image software, such as the SIMATIC PC/PG Image & Partition Creator , entire hard drive partitions of the work drive can quickly and easily be stored as files on the second hard drive. Should the work drive malfunction, these files can quickly and precisely restore the partitions – even on a replaced hard drive. This approach is recommended, for instance, if the hard drive is split into multiple user-specific or task-specific partitions, that are to be backed up independent of each other. 
• Setting up an identical Hard Drive Image 
  With a hard drive image software, such as the SIMATIC PC/PG Image & Partition Creator a precise data image of the complete work drive can quickly and easily be placed on the second hard drive, creating an identical image of the work drive. In the case of a malfunction with the wok drive, the second hard drive could quickly be changed into the work drive.

SIMATIC Panel PC 677B  with Option: RAID 1  configuration

The automatic, redundant data management (data mirroring) with RAID 1 during PC operation is recommended to protect against data losses and to minimize downtimes in case of physical damage (head-crash, overheating, etc.) to the storage medium.

The major advantage of a RAID system lies in its ability to keep the system running without interruption and costly downtimes in the case of a malfunction (fail-over-capacity). However, if hard drive data is damaged or destroyed through operating errors, faulty software components or viruses, a RAID system does not offer any protection, since all write operations take place simultaneously on both hard drives. As a protection against this threat a backup of the configuration and data on an external storage medium via SIMATIC PC/PG Image & Partition Creator is recommended.
 

• Protection against Data Losses in case of Hard Drive Failure
  RAID 1 provides extensive protection against data losses in the case of a hard drive failure. Every write operation to one hard drive of the PC is performed in parallel on a mirror drive, so that identical hard drive contents are available at any one time. The simultaneous failure of both hard drives is rather unlikely.
• Protection against Downtimes 
  In the case of a problem with one hard drive, the application will continue to run without interruption. The functions of the “productive” drive are assumed by the mirror drive. The user can continue to work until a self-defined service date, at which the faulty hard drive can be replaced. However, during this timeframe, no increased availability exists.
• Easy Restoring of Data on the Replacement Drive
  If one of the two hard drives has to be replaced, the newly installed hard drive will be integrated into the RAID1 functionality – the mirror data is then automatically copied (auto-rebuild)