IT services supplier Anite has deployed iSCSI networked storage using Lefthand Network's SAN/iQ software-based...
product. The Lefthand SAN product, using a tiered combination of SAS and SATA hard drives running on HP and Dell servers, was implemented in conjunction with a VMWare virtualisation project, and chosen over a NetApp array on cost grounds as well as its ability to create networked storage from servers.
Anite supplies software solutions to mobile telcos, the public sector, and travel businesses internationally and runs two data centres for its internal-facing activities at Fleet and Slough serving Microsoft CRM and financials plus software development management applications to 1,000 staff.
Anite group IT director Jeremy Moss wanted to to centralise storage and gain greater utilisation as part of a wider project to implement VMWare server virtualisation. The existing set up was one of many physical servers dedicated to specific apps with their own DAS or (NetApp) NAS storage.
He said, "We wanted to move to a more integrated infrastructure using VMWare, and that decision was taken to enable us to lower costs and simplify the platforms we use. We needed a SAN too, not for reasons of performance or centralisation, but for cost efficiency and ease of management, as we had been just adding servers here and there."
The networked storage product Anite chose was Lefthand's SAN/IQ, which is a software-based method of linking hard drives in servers – it is compatible with some HP and IBM hardware as well as VMWare ESX virtual servers – and configuring these as a SAN.
So far Anite has implemented eight paired Lefthand nodes running in mirrored RAID 5 on HP hardware to provide 60 terabytes of storage for eight VMWare ESX servers which provide around 100 virtual servers with nearly 180 volumes, each replacing a physical drive. Of these 180 volumes around 150 use SAS disks to gain a performance edge although total data is divided roughly in two between SAS for low volume virtual machine images and SQL storage and SATA drives for high volume file storage.
The Lefthand SAN/IQ was chosen in competition with the NetApp FAS 3020 array. According to Moss the benefits of the Lefthand product are that Anite is not going to be locked into a specific hardware supplier's equipment as its storage needs grow, as well as being cheaper on a per gigabyte comparison.
Anite offers NetApp arrays to its local government clients so it tested one as a potential solution to its storage needs, says Moss.
He says, "One of our departments had worked with NetApp so we looked at their FAS 3020. But, being a hardware solution we were concerned about being locked into that provider's equipment and maintenance. We wanted hardware vendor independence. That's where SAN/iQ wins – it's just software so there's no platform lock-in. It also came in at half the cost per gigabyte of the NetApp product."
Moss declined to disclose what they paid for Lefthand licences but in the UK it is around £10,000 for each server clustered while a Netapp FAS3020 filer head with protocols installed would have set them back around £20,000 with additional costs of around £15,000 for each 4.2 TB set of SATA disks.
Anite is a Dell/HP shop but wrote storage products from these two out of the equation early on, because it wanted independence from a specific vendor's hardware. It had also had a bad experience previously with unreliable firmware on Dell PowerVault products, says Moss.
Storage admins access the Lefthand system via a Java-based management console that runs on a Windows or Linux machine connected to the iSCSI network. Using the console, users can combine nodes into a cluster and create volumes from that pool of storage and assign it to an application server. When nodes are added, SAN/iQ automatically redistributes existing volumes over it. This also improves performance by spreading I/O operations over more disks. The software also features thin provisioning.
Lefthand's approach is one which allows users to make the best use of existing assets or commodity storage hardware, says Simon Robinson, research director for storage with the 451 Group.
He says, "Lefthand's approach is quite novel – to sell the software only and to leave it up to the user to decide on the hardware to be used. It provides flexibility and the ability to use existing hardware instead of going out and buying new. If you have servers hanging around you can use clustering software to turn them into a virtual appliance."
Such an approach naturally appeals to smaller operations, says Robinson.
"If belts are being tightened and this allows the user to get more out of their existing assets, that's a good thing. It would appear as something more suited to smaller operations, but so far Lefthand has around 3,000 customers of all sizes, though it is still early days. They have been going for remote and branch office type implementations where users can create pooled storage without dedicated hardware."
A key drawback of Lefthand's SAN/iQ, says Robinson, is the lack of NAS capability.