Monday, February 24, 2014

Host based Vs SAN based replication

Host based Vs SAN based replication:

Source: http://www.linuxclustering.net/2012/11/07/host-based-replication-vs-san-replication/

Host Based
 SAN Based
1. Host-based replication doesn’t lock users into a particular storage array from any one vendor, can replicate from any array to any array, regardless of vendor.
This ability ultimately lowers costs and provides users the flexibility to choose what is right for their environment.
 Most host-based replication solutions can also replicate data natively over IP networks, so users don’t need to buy expensive hardware to achieve this functionality.



2. If the business demands zero impact to operations in the event of a site disaster, then host-based techniques provide the only feasible solution.

3. One disadvantage is that host-based solutions consume server resources and can affect overall server performance. Despite this possibility, a host-based solution might still be appropriate when IT managers need a multi-vendor storage infrastructure or have a legacy investment or internal expertise in a specific host-based application.

1.Storage-based replication is OS-independent and adds no processing overhead.
However, vendors often demand that users replicate from  and to similar arrays.
This requirement can be costly, especially when you use a high-performance disk at your primary site — and now must use the same at your secondary site.
 Also, storage-based solutions natively replicate over Fibre Channel and often require extra hardware to send data over IP networks, further increasing costs.

2. A storage-based alternative does provide the benefit of an integrated solution from a dedicated storage vendor. These solutions leverage the controller of the storage array as an operating platform for replication functionality. The tight integration of hardware and software gives the storage vendor unprecedented control over the replication configuration and allows for service-level guarantees that are difficult to match with alternative replication approaches. Most storage vendors have also tailored their products to complement server virtualization and use key features such as virtual machine storage failover. Some enterprises might also have a long-standing business relationship with a particular storage vendor; in such cases, a storage solution might be a relevant fit.


Pros
  • Storage agnostic
  • Sync and async
  • Data can reside on any storage
  • Unaffected by storage upgrades
  • Single vendor for storage and replication
  • No burden on host system
  • OS agnostic
Cons
  • Use of computing resources on host

  • Vendor lock-in
  • Higher cost
  • Data must reside on array
  • Distance limitations of Fibre Channel
Best Fit
  • Multi-vendor storage environment
  • Need option of sync or async
  • Implementing failover cluster
  • Replicating to multiple targets
  • Prefer single vendor
  • Limited distance and controlled environment
  • Replicating to single target


No comments:

Post a Comment