Buffalo Technology TeraStation Pro II iSCSI review
Uptake of IP SANs in the mid-range business markets may be growing exponentially but Buffalo’s new TeraStation Pro II aims to extend affordable iSCSI to the smaller business. This is an area where this technology has had virtually no penetration as the Thecus N5200PRO (web ID:137454) was until now the first and only desktop appliance to support iSCSI.
Buffalo’s stance is substantially different to Thecus’ as the new TeraStation is not a NAS appliance and is designed purely to offer up its storage only as iSCSI virtual volumes. The appliance is offered in either rack mount or desktop chassis with the latter on review physically identical to Buffalo’s standard NAS appliances.
The review model came with a quartet of 250GB SATA hard disks which do not support hot-swap. Coined by Buffalo as quick-swap, the drives are connected to the controller board with combined power/SATA cables so the appliance must be powered down before they can be removed. Buffalo advised us that it provides a next day replacement service for failed drives and will send out a new unit complete with carrier. Note also that the USB ports only support an intelligent UPS and not external storage.
The installation routine just loads Buffalo’s connection tool which deals with iSCSI initiator configuration. On loading it scans for the appliance and, providing you have Microsoft’s free iSCSI initiator software downloaded and installed, will sort out adding a target portal and logging on to available targets. You can also request persistent connections to be enabled as well. All very handy but you can ignore it and configure the initiator software directly.
By default, the appliance’s storage is set up with all its disk space assigned as one virtual volume so when you add the portal you are offered a single target. To make any changes the iSCSI service needs to be stopped using the button at the top of the web interface. If you want to divide up the array into smaller targets you need to enable the LVM (logical volume manager) feature. However, LVM does hit performance and Buffalo’s manual writers expect you to be psychic here as LVM isn’t even mentioned in the user guide.
Access can be restricted to each volume with a username and password that the connection tool will request. You can also use Buffalo’s mutual authorisation and restrict access to specific client IP addresses. Yet again these features aren’t even mentioned in the manual and the on-line help from the web interface is simplistic at best.
Performance with LVM disabled is quite respectable with the Iometer utility reporting a raw read rate of 56MB/sec with the target logged on to a Boston Supermicro 3.2GHz Pentium D workstation. With LVM enabled this dropped noticeably to 44MB/sec. With virtual volumes logged into from two different workstations we saw a cumulative read throughput of 37MB/sec. Real world tests copying a 690MB video clip reported good read speeds of 43MB/sec but the RAID array took its toll on write speeds with the file copy returning only 15MB/sec.
Buffalo’s new iSCSI appliance looks an unfinished project as the web interface is scrappy, the LVM feature hits performance hard and the user manual is abysmal. Performance is quite reasonable but for the price we would have expected a far more sophisticated IP SAN solution from this NAS specialist.