Case Study: Maximizing Storage Value with IP SANs Page 2
Transitioning to IP
The city decided initially to install a traditional FC SAN in order to consolidate one TB of storage it used for various databases and Microsoft Exchange. HP, EMC, StorageTek, and XIOtech each proposed entry-level solutions. EMC and StorageTek were eliminated due to initial cost and perceived complexity. HP StorageWorks MSA1000 appealed to the City due to its cost, integrated FC switch, ability to scale, and compatibility. XIOtech's Magnitude was more expensive, but its built-in virtualization, lack of LUN masking, and ability to pool disk capacity and stripe across non-identical disks were compelling to the city.
IT consulting firm Satel Inc. introduced Ogden to an IP-based SAN by Lefthand Networks that is based upon Network Storage Modules (NSM). Unfortunately, Lefthand at the time used a proprietary connectivity protocol called AEBS (Advanced Ethernet Block Storage) that was developed prior to the adoption of the iSCSI standard. Despite this, the City decided to move forward with Lefthand, as an iSCSI-complaint driver was in testing.
In addition to the NSMs from Lefthand Networks, the IP SAN consisted of a XIOtech Magnitude and an HP MSA1000.
The end result? Cost per megabyte dropped from $0.62 to $0.18, utilization rates rose from 50% to 75-80%, and the city now manages triple the storage capacity with less than half the staff. Further, it has shorter backup windows, has improved its Mean Time to Recovery, and has increased bandwidth availability on the existing production LAN/WAN.
To provide one TB of fully redundant storage, five NSM 100 units were purchased. They were connected with a 24-port Cisco 3750 non-blocking 10/100/1000 Mbps Ethernet switch. Each NSM 100 is a 1U form factor unit that includes controllers and storage enclosures and provides 500GB of storage using 4 hot swappable ATA drives.
Four of the NSMs are configured using volume-level resilience, ensuring that one failed unit will not result in loss of data. This automatically replicates a redundant copy of all content on alternate NSMs, thus the 4 NSMs would yield 1 TB of usable data storage. A 5th NSM is configured as a hot spare to automatically replace any failing NSM.
The NSMs are connected using standard Gigabit Ethernet infrastructure and function in a peer-to-peer arrangement. The SAN is physically isolated from Ogden's existing production LAN/WAN so that performance and security are not adversely affected by network traffic.
"The whole process from start to finish required less than four hours from the time we broke the tape on the cartons until the drives were online and ready to be loaded with data," says Brummett. "Calculated cost per megabyte has dropped from $0.62 to $0.18 without factoring in the reduced cost of management or the leveraging of existing Ethernet know-how."
Feature courtesy of Enterprise IT Planet.