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In less-picturesque terms, SANMelody V 1.4.0 is the latest "storage server" software from DataCore Software, Ft. Lauderdale, FL. Intended for SMBs and enterprise departments, it provisions and manages storage connected to general-purpose systems running Windows, Linux, Unix, NetWare and Mac OS.
SANMelody is essentially a storage virtualization product and as such, enters a competitive space with players such as FalconStor Software, Hewlett-Packard Co. and StorAge. It's a hotly contested arena because the product that serves up your volumes will also serve as the foundation for all other storage management solutions that operate on a presumption of access to physical storage.
I downloaded SANMelody from DataCore's Web site and installed it on a SAN-attached Windows 2000 Server as a storage server. Client application hosts consisted of a second Win2K box and a wireless laptop running XP Professional. Supported operating systems include Windows 2000, XP and 2003 32-bit editions. However, client application hosts can be Windows, Unix, NetWare, Linux or MacOS. Minimum hardware requirements for the storage server are:
- 300MHz processor
- 512MB of memory
- 100MB of disk space for binaries and configuration data
- Fibre Channel (FC) or iSCSI interface to a scalable storage solution (if the storage is located inside the server chassis, only an Ethernet port is required)
- A second communication interface for presentation to your application servers
Installation was straightforward, with prompts familiar to typical Windows installation activities. During installation, SANMelody installed Emulex, LSI and QLogic FC drivers as well as an iSCSI driver. To have application hosts connect to your storage server over iSCSI, you'll need either an iSCSI adapter and its associated driver, or simply a software iSCSI driver that uses a generic NIC without a TCP offload engine as an interface to your IP SAN. Except for Mac OS and NetWare, iSCSI drivers for supported client operating systems can be found on Cisco's Web site.
But a SANMelody storage server should always use an iSCSI adapter with an offload engine because it will be the target of iSCSI requests initiated from multiple application hosts; it will also enhance the scalability of the storage server.
If you plan to use FC as an application host connect and you've already standardized on HBAs other than those listed here, have DataCore and your switch vendor certify your HBAs before purchasing SANMelody. Although this is software, you must go through the certification process as if your HBA will be talking to a storage array port. In addition, you will also need to purchase the associated FC manager snap-in that provides basic configuration and troubleshooting data for the FC HBAs in the storage server.
Four services were created during installation, three of which are started automatically. These three services handle the monitoring of application host channels, LUN presentation and the synchronization of configuration data with other storage servers in a region.
The Windows server used for this review was configured with 512MB of memory and is a multipurpose server, dedicated to a storage server. With other processes running, page swapping occurred when starting the storage server. But when I stopped those processes, SANMelody executed without invoking swapping.
It's also important to note that buffer cache used to hold frequently referenced data is reserved from the physical memory in the storage server in a cyclical fashion. Therefore, it behooves you to consider the size and performance of that memory as part of the configuration assessment. Make sure that applications on the storage server won't be starved for memory.
This was first published in June 2004