Edge10 DAS200 用户指南

(FAST) 

 

The STRIPING storage policy distributes access across all hard disks, also called FAST (equivalent to RAID 0). 

STRIPING presents the best data speed but no data redundancy. STRIPING storage policy accelerates hard disk 

operating speed by using many disks in parallel. Hard drive data segments are written to different disks 

simultaneously which increases performance while sacrificing data redundancy. 

To implement the STRIPING storage policy, the DAS200 Storage creates a single virtual volume that is 

 

striped across both hard drives, with a storage capacity that is equal to the sum of both hard disk drives. 

 

It is possible to set any node within a cascaded configuration to STRIPING, although there is no performance 

benefit when using multiple layers of striping. 

 

 

(SAFE) 

 

The MIRRORING storage policy stores all data in duplicate on separate drives to protect against data loss due to 

drive failure. One drive mirrors the other at all times, equivalent to RAID 1. Every write operation goes to both 

drives. MIRRORING provides the highest level of data protection for critical data that you cannot afford to lose if a 

hard drive fails, but halves the amount of storage capacity because all data must be stored twice. The resulting 

storage capacity of the virtual MIRRORING volume will be equivalent to the size of one hard drive (if both drives 

are the same) or the smaller of the two drives (if they are different). 

 

If one drive fails, the MIRRORING volume is still usable, but it is in a vulnerable state because its mirrored hard 

drive is inaccessible. When the offline drive comes back online, the appliance begins a rebuild process 

immediately to restore data redundancy. A message appears in the LED indicator to notify you that a rebuild is in 

progress. 

Although the volume remains available during the rebuild process, the volume is susceptible to data loss through 

 

damage to the remaining drive until redundancy is restored at the end of the rebuild and verification process. Host 

access takes precedence over the rebuild process. If you continue to use the MIRRORING volume during the rebuild, 

the rebuild process will take a longer time to complete, and the host data transfer performance will also 

be affected. 

 

Any node within a cascaded configuration can be set to MIRRORING, but it is more efficient to use the 

 

MIRRORING policy at the lowest possible level within the hierarchy. 

 

It is also possible to create a MIRRORING volume using one hard disk drive connected to Port 0 of the TEAR 

 

 

Ver. 071004 

DAS200 User’s Manual 

 

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