When it needed to expand its storage capabilities, online desktop SaaS provider Sapotek Inc. found Sun Microsystems'...
Thumper server and ZFS file system a more scalable alternative to an iSCSI SAN.
Like many young Web companies, Sapotek needs storage that is reliable, easy to manage and won't break its budget, since a glitch can prove fatal to business. Sapotek provides its customers with a virtual desktop, complete with free online desktop applications, such as word processing, email and messaging. Sapotek claims it has 200,000 users of its Desktoptwo service and plans to offer an enterprise system over the next year that could tax its resources even more.
CEO Joshua Rand said Sapotek's first storage decision was whether for Sapotek to host the storage infrastructure or go with a managed provider while preparing to launch the site in 2006. He decided to do it in-house and started with a Dell/EMC AX100i iSCSI SAN. With only two people to manage his system, iSCSI seemed the way to go.
"We maintain our own internal storage for reasons of security and because our system is scalable, so we like to keep things in-house," Rand said. "We put together our own cluster which worked well initially. We had five Dell servers running Linux and an AX100i with 3 TB on 12 SATA drives."
Rand said he soon ran into limitations with the AX100i because it couldn't scale as Sapotek's storage needs grew. "Once we outgrew that setup, we had to look elsewhere," he said.
About a year ago, Sapotek joined Sun's Startup Essentials Program that offers discounts to new companies. "Sun hardware would've been too expensive, but for this program it costs us less than we were paying Dell," Rand said. "We cut our expenses in half. Monthly recurring fees are less than $3,000, while before we were pushing $6,000."
Rand said he was also looking to move off Red Hat Enterprise Linux to Sun's Solaris 10 operating system. "We were trying to do it lock, stock and barrel, migrate all Web applications to the SAN stack, rather than to a LAN stack," he said. "We were purchasing Sun X4200 servers, and we needed storage on the back. Sun recommended X4500, or what everybody calls 'The Thumper.' " Sapotek still uses the AX100i for testing, but has outgrown it for primary storage. Rand said, "We use Thumper for our main storage device, and we went from 3 TB to 24 TB overnight. It cost about a dollar a gigabyte, and there's an incredible amount of density in a 4U system."
Sapotek currrently uses around 7 TB of that 24 TB. Rand said if he maxes out at 24 TB, he'll either swap it out for a larger storage system or set up a redundant cluster. "It's a stackable unit, so we can just add more," he said.
From a performance standpoint, Rand said Sapotek has benefitted by switching from the Global File System (GFS) for Linux clusters to Sun's open source ZFS. He said with Red Hat GFS he couldn't go beyond five concurrent threads per server, but with ZFS he hits 32 concurrent threads.
"ZFS is amazingly fast," he said. "GFS was extremely unreliable with files. It would lock once in a while. ZFS is built to operate with Solaris and X4500 storage. It's like each of the cluster nodes had storage locally." Sapotek has encountererd no locking problems with ZFS. "And before," said Rand, "backing up user files was cumbersome and resource-intensive. With ZFS, we're using snapshots. We take user data, make snaps and export to old units."