Writing for Datamationis IT Management site, Unix/Open Systems Administrator John Welch observes that "with the Xserve, the company once labeled as being for iartists onlyi has become more than just an irritant to IT departments at all levels." His latest column delves into Xsan, Appleis storage area network (SAN) file system. Mr. Welch notes that it and ADICis StorNext are the only file systems that Mac OS X machines work with, but he says that Apple makes up for it with per-machine pricing thatis cheaper than its competitorsi offerings. He adds: "Hopefully, Xsan will increase the downward pressure on SAN licensing costs just as Appleis AirPort did with wireless networking at the turn of the century."
On the limitations side of the coin, Mr. Welch points to a few things, starting a potential speed drop that comes when a large number of clients connect to SAN front ends at the same time, unless the system is set up properly. He goes into the technical details that explain why this happens. He also notes that Xsan "can only stripe multiple RAID LUNs into a storage pool." Finally, "while Xsan can be quite a bit cheaper than other SAN implementations, you have to factor in hardware costs that some SAN-in-a-box products take care of for you."