The cloud may be the new frontier, but not all cloud-based services are gaining traction. The public cloud storage market has faltered as three companies have abandoned their cloud infrastructure as a service (IaaS) efforts over the past year, according to Gartner. The most recent fatality comes from Iron Mountain, which announced last week that it would close its Virtual File Store after only two years. While the enterprise-class archiving and data management services were dubbed a cheaper alternative to in-house storage, customers were apparently hard to find. Other vendors that have closed their cloud storage services include the startup Vaultscape, which launched its service in 2009 and closed its doors in 2010; and EMC, whose Atmos Online went live in 2009 and closed a year later. Iron Mountain says it stopped accepting new customers as of April 1, but will continue to offer services to its current customers while it helps them either migrate to another provider or reclaim their data. The wrap up will be done around the first half of 2013. Now, only Nirvanix and Zetta remain as pure-play public cloud providers of network attached storage.