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Storage and backup
"Exchange works best with storage consolidated at regional data centers. There you also can have your high-availability clustered servers," says Rodgers. He usually recommends iSCSI with NAS arrays, such as those from Network Appliance Inc., which will do the job at a lower cost than a Fibre Channel (FC) SAN.
Hyperion, however, took the FC SAN route. "We used two EMC [Corp.] Clariion storage arrays with FC drives. It was redundant storage. We've never had a Clariion go down," says Tiseo. He realizes it's a more costly configuration than necessary, but the company likes the scalability of the Clariion and its reliability. In the future, Tiseo expects to add lower cost, second-tier storage.
Although Exchange doesn't require more storage, Hyperion's growth has driven an increase in Exchange storage. The company initially set up 3TB of mirrored storage on the two EMC Clariion CX700 arrays (1.5TB per array). It then uses Exchange's policy management to enforce retention policies. "We can set different retention policies for different groups. For instance, we can retain e-mail for VIPs for longer," says Tiseo. The current general retention policy is 180 days, after which e-mail is deleted.
For the future, Tiseo is exploring e-mail archiving in which messages would be automatically moved to lower cost SATA-based storage after 180 days. "This would free capacity on the production storage, and we wouldn't be spending a lot
For high availability, Hyperion runs active/passive Exchange clusters at each regional hub. Hyperion originally intended more complicated multiserver clusters, but found them too difficult, forcing the firm to go with single active/passive pairs for its clusters. "Exchange is not very cluster-aware, and it is not good at automated failback," says Tiseo. The company manually switches Exchange back after a failover.
In addition, the company configures the storage for increased availability by putting the database and logs in separate RAID groups. Tiseo also stripes RAID groups across enclosures. "That way, there is no single point of failure within the cabinet," he says.
Hyperion backs up Exchange using Symantec Corp.'s Veritas NetBackup with Exchange agents. Backups go to disk first and then to tape. Recovery parameters are seven days for deleted e-mail and 14 days for a deleted mailbox. Outlook clients are configured to archive mail to local .PST files every 90 days.
This was first published in October 2006