The transtec’s PROVIGO 210 Mini-SAN represents another stab at the small business network storage market by Zetera Corporation and its unique Z-SAN technology. We first came across its SoIP (storage over IP) nearly two years ago when we looked at Netgear’s Storage Central SC101 which at the time impressed but a year down the line came under fire with some damning criticisms from us for a number of reasons.
One problem the 210 will certainly overcome is the potential overheating issues of the SC101 as this solidly built desktop chassis combines four hot-swap SATA drives with a decent cooling system. transtec has also improved the management interface and added a lot more features than you’ll find in the Netgear Storage Central products.
The 210 is designed to offer a more cost-effective storage solution to iSCSI appliances and in this area it certainly wins out as our review model was equipped with a quartet of 250GB Seagate Barracuda SATA drives and comes in at a very low price. In fact, transtec can deliver a system with four 1TB drives for less than a grand – a price point that iSCSI can’t hope to compete with.
So how does Z-SAN, or SoIP, work? Essentially, the appliance’s controller functions as a DHCP client and on power up grabs an IP address for itself plus one for each of the drives. Using the bundled Storage Manager utility you then carve up the drives into volumes, or IP partitions, and as they are created they’ll each get an IP address as well.
The possibilities are endless as each partition can be shared and password protected and you can expand them into spare space on the fly. Add another appliance on the network and you can even span existing partitions into it. They can be striped or mirrored, configured as a RAID-10 array and you can decide how much space on each selected drive a partition should use.
Each partition uses an LBA (logical block address) range which determines where data is written to or read from and each client system requires a filter driver that converts file system commands into IP traffic and a SCSI miniport driver which are installed along with the management utility. Partitions appear to client systems as local hard disks – the same as iSCSI - although if you want to share them you must create them using the proprietary Z-FS file system. NTFS is supported but these partitions can only be used by the client that created them.
The Storage Manager is superior to Netgear’s management tools as it offers far more information about the drives and partitions and provides pie charts showing free and used capacity. It also uses the Windows SNMP trap service to provide pop-up warnings in the System Tray for errors or faults. However, we did find our Windows clients occasionally having problems with Z-FS partitions as they wouldn’t always assign a drive icon to them. Furthermore, if you want to use the 210 to secure workstation data you’ll have to source your own backup software as transtec doesn’t provide any.
The 210 may cost less than most iSCSI appliances but general performance puts it firmly on a par with NAS appliances. Connecting it to our Gigabit network we copied a range of files to and from a Supermicro 3.2GHz Pentium D workstation and saw Z-FS partitions returning average speeds of around 22MB/sec and 20MB/sec for read and write speeds.
NTFS partitions proved to be more efficient as speeds climbed to nearly 28MB/sec and a four drive spanned partition upped this slightly to 29MB/sec. With two appliances on the bench we also created a mirrored partition across them as saw this deliver average read and write speeds of around 22MB/sec and 15MB/sec. During testing we encountered none of the problems that afflicted the Netgear solution with the drives keeping a cool head and our mirrors remaining stable.
Z-SAN is clearly a very interesting storage technology but it hasn’t had many takers as despite being around since 2005 only Netgear and transtec have given it any exposure in the UK and European markets. It’s certainly better value than iSCSI but being a proprietary technology as opposed to standards based will always be a drawback.
If Z-SAN piques your curiosity then we would recommend the 210 Mini-SAN as the one to go for. It’s far superior to the Netgear alternative and is particularly good value but performance isn’t great and bear in mind that it’s not standards based so there’s an element of risk in using this as a business storage solution