Remote storage replication: Open source RAID

  • Author(s) / Creator(s)
  • Nowadays storage area networks (SAN) have become an important part of small and large enterprises, where the need of a reliable and flexible architecture for storage across different location arises. Having said this, the selection of the very basic components where the storage solution will be implemented play a decisive role on the future success and scalability of the solution. The components mentioned above constitute a primary task of storage networks and it is accomplished by remote replication, which purpose is basically provide access to remote block devices that are not located on the same physical machine or system where the host is. Currently there are multiple hardware and software commercial implementations for
    remote replication, as well as different open source solutions; this project tries to give a big picture of some of the most commonly used solutions on the open source side, and shows the performance and stability of one particular implementation composed by software RAID and iSCSI.
    This implementation incorporates two widely used technologies, software RAID-1 and iSCSI; both are standard and are well documented. Here, the stability of the iSCSI protocol implementation is tested and compared to the network block device NBD (open source solution for block device representation). Then, having a stable block device mapping technology the next step for remote replication is integrate Linux MD (software RAID driver), a tool that duplicates the data and synchronizes it among different disks. Linux MD provides several advantages further than just raw data replication, including reading performance improvement and write intent log capabilities. These features are presented in the project and their applicability on the remote replication task is discussed. Finally the performance of the iSCSI –MD model is analyzed with the IOZONE File system benchmarking tool and conclusions from the results are presented.

  • Date created
    2008-04-01
  • Subjects / Keywords
  • Type of Item
    Report
  • DOI
    https://doi.org/10.7939/r3-hztx-6g89
  • License
    Attribution-NonCommercial 4.0 International