Administrator Guide

Live Volume with Linux/UNIX
83 Dell EMC SC Series: Synchronous Replication and Live Volume | CML1064
10 Live Volume with Linux/UNIX
Synchronous replication is a feature of SC Series that allows two copies of data to be maintained on separate
SC Series arrays using one or multiple replication relationships. These two arrays can be in the same
location, or can be geographically dispersed and connected by a WAN. Synchronous replication functionality
is subdivided into two user-configurable operating modes, high consistency and high availability; these two
modes are discussed in further detail in section 3.1. Additionally, the synchronous replication mode can be
changed "on demand" depending on the needs of the customer.
Note: The serial number of the replicated volume on the destination SC Series array is unique, and different
from that of the source volume.
When Live Volume is coupled with synchronous replication, it allows customers to deploy and manage
identical data integrity guaranteed copies of data to a secondary SC Series array at an alternate location. The
use of Live Volume creates value in this scenario, by masking the serial number of the replicated volume on
the destination SC Series array and making the serial number appear identical to that of the source volume.
The ability to maintain an identical serial number volume (or volumes) on the destination SC Series array
simplifies and expedites the ability to recover from this volume (or volumes) into the destination application
stack.
10.1 Live Volume and Synchronous Replication
The use of Live Volume in conjunction with synchronous replication in Red Hat
®
Enterprise Linux
®
deployments offers customers the ability to safely and resiliently manage, back up, and recover their
business-critical data across both single- and multi-site deployments.
The remainder of this section discusses some of these use cases along with certain technical considerations
in these scenarios, respectively.
10.2 Live Volume managed replication
Live Volume managed replication (LVMR) is the ability of SC Series arrays to replicate and manage a third
copy of data. It is always attached to the primary SC Series array in a Live Volume scenario. If the SC Series
roles are swapped, the LVMR volume will always follow the array that assumes the primary role. The mode of
replication used for the LVMR volume is described in Table 2, which shows there is a maximum of one
synchronous replication pair in any scenario.
Live Volume replication modes
Live Volume at Site A
Replication mode of Live Volume
to site B
Replication mode of LVMR to site C
Live Volume
Synchronous
Asynchronous
Asynchronous
Synchronous
Asynchronous
Asynchronous