Review

From Network Computing Vol 18 No 05 September/October 2009

IP SANs are enjoying an exponential uptake in the SME sector as they provide a highly cost-effective alternative to Fibre Channel (FC) SANs for network based storage. DataCore's SANmelody goes one step further by allowing you to create IP SANs from your own choice of hardware, tohelp with costs.

This latest version adds support for 32 & 64 bit Windows Server 2008 and augments this with a wealth of interesting new features. You have DataCore's 'mega cache' which can improve performance by accelerating I/O responses. The cache can be up to 1TB in size, and it uses the host system's processor and memory to anticipate disk read andgroup writes.

SANmelody offers support for unlimited host connections, and its ability to use just about any type of storage medium is impressive; if the host system can see the drive, SANmelody can use it. Installation and deployment is a simple task as SANmelody is accessed via an MMC snap-in, and you can view and configure the software, drivers and storage devices from the standard Windows Computer Management interface.

Drives and partitions are prepared first using basic disks that have not been formatted or given a drive letter. Along with linear drives, SANmelody supports storage pools comprising multiple physical drives. Thin provisioning is also on the menu as NMVs (network managed volumes) allow you to present virtual volumes to application servers that are much larger than the available physical space.

SANmelody monitors the disk space that is used in NMVs, dynamically allocates disk blocks as required, and supports virtual volumes of up to 2TB. A further feature is space reclamation in thin provisioned volumes; space used by previously deleted files is automatically returned to the storage pool. You can even create your own FC SAN as SANmelody offers optional support for fibre-channel HBAs.

Your host systems must first be logged on to the SANmelody system; they only require Microsoft's freely available iSCSI initiator to be installed. These are then declared as application servers to SANmelody and their iSCSI connections are assigned to them as storage channels. The raw storage volumes on the host system are defined as virtual volumes and mapped to selected hosts so providing strong access security. SANmelody is hot on disaster recovery and supports MPIO (multi-path I/O) using multiple paths from hosts to virtual volumes, creating redundant physical links. RAID striping is supported as standard, as are volume snapshots and remote site replication. AIM (asynchronous IP mirroring) allows a virtual volume at one location to be mirrored over an IP link to another server. During performance testing SANmelody was deployed on a Broadberry CyberServe 1U rack system equipped with dual 2.8GHz X5560 Xeons, 12GB of DDR3 memory, and running Window Server 2008. Creating multiple iSCSI targets was simple and we could easily assign them to our 2003/2008/XP clients all running Microsoft's iSCSI initiator v2.08.

Performance was extremely good and with a Windows Server 2003 system logged into a single 50GB virtual volume we saw the Iometer utility returning average raw read speeds of 112MB/sec over Gigabit Ethernet. This is indistinguishable from the typical performance we've seen in the lab from IP SAN appliances, showing that SANmelody has the measure of higher cost and proprietary disk array solutions. We've always found SANmelody to be a solid software alternative to IP SAN disk arrays and this latest version is even more sophisticated. It offers extremely good value to SMEs while delivering top performance and an impressive range of enterprise disaster recovery, along with some high availability features.NC

Product: SANmelody 3.0
Supplier: DataCore Software
Telephone: 0118 949 7024
Web site:www.datacore.com
Price:Starts from 0.5TB, £1,074 excluding VAT

Review