madunix
Member
- Joined
- Apr 9, 2010
- Member Type
- Academic
- Native Language
- German
- Home Country
- Germany
- Current Location
- Germany
Basically two varieties of replication are distinguished: the synchronous and asynchronous. Synchronous replication is a cross reference with RAID1, just over larger distance: Only if the data in both storage systems are safely on disk, the application receives the appropriate response. As a result, when a failure of memory or the secondary link there that forced labor is at a standstill. On the other hand, it is only with synchronous replication to achieve Zero Data Loss Policy. With asynchronous replication; the application receives the feedback already, if the data resides on the local disk. The transfer to the secondary system takes place after the event on the background. Data loss can therefore not be completely ruled out.
A significant disadvantage of synchronous replication is the delay of the feedback. Which depends, among other things, the distance between the mirrors? One kilometer of fiber optic transmission delay as the signal by about 5 microseconds.
A significant disadvantage of synchronous replication is the delay of the feedback. Which depends, among other things, the distance between the mirrors? One kilometer of fiber optic transmission delay as the signal by about 5 microseconds.