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Limited storage support
Maybe the biggest problem facing enterprise storage managers is today's limited tool selection for Linux storage. For example, Veritas offers a clustering file system for other platforms, but the Linux version isn't expected until early 2004, Veritas' Nevatia says.
Many of Computer Associates' (CA) BrightStor enterprise storage management products have been ported to Linux. However, CA's SAN Manager and SAN Designer have not. But there is a workaround, says David Liff, vice president, BrightStor brand marketing: "Most companies don't have Linux-only SANs," but companies can manage Linux on mixed SANs using Windows or Unix versions of the CA tools along with its Linux agents.
The Linux storage tool picture is improving seemingly weekly. For example, PyX Technologies, El Cerrito, CA, has developed both client and server software based on Linux for iSCSI-enabled storage. The product--which made its debut in August--fully conforms to the iSCSI standard as ratified by the Internet Engineering Task Force (IETF), according to PyX. Its iSCSI software is being bundled into products from ASA Computers Inc., Database Appliances and Pogo Linux Inc.
Instead of waiting for tools from major storage vendors, many Linux administrators manage Linux storage with tools--often free--from the open-source community. Administrators simply download tools such as MRTG, which tracks and graphically displays network conditions, and Samba, which provides file and print services to server message block (SMB) clients, right off the Internet. "There is a lot of freeware out there," says Eric Wright, an independent Linux consultant, Annapolis, MD, and creator of The Linux Spot Web site. Other online sources for tools are: www.Linux.org and www.Freshmeat.net.
The Linux Spot runs on an IBM Netfinity Pentium server with an IBM ServeRAID Ultra 160 SCSI RAID 5 controller and a Compaq ProLiant external RAID array. At one point, The Linux Spot ran almost 1TB of direct-attached SCSI storage, although Wright has cut it back as he shifted the site to primarily FTP serving.
Many small Linux sites still get by with internal disk storage or a small directly attached array. Typical is Tarot.com, which provides online divination, readings and astrology. "We just use internal storage, no NAS, no SAN," says Eric O'Dell, senior database administrator.
The company keeps its two million record customer file on a MySQL database running on Red Hat Linux. It has a generic Intel server with dual Zeon processors. The company is only now focusing on storage with the acquisition of its first external RAID array. Two database servers will share a 45GB partition, leaving 90GB of unused capacity for growth, O'Dell explains. The biggest decision: which shared file system to use, Sistina's GFS or ext3. After trying both, the company settled on ext3, a popular journaling file system. "We were experiencing a [database] consistency problem and ext3 resolved it," O'Dell says.
Few companies have converted their large enterprise storage infrastructures to Linux or are likely to do so, at least anytime soon, suggests IDC's Kusnetzky.
Increasingly, however, organizations are adding Linux systems into their environments, often starting with a DNS or Apache server and expanding from there. In the process, they are incorporating Linux servers into their storage strategies. Storage vendors are closely monitoring the trend. HBA manufacturers, management software providers and other storage vendors are slowly supporting Linux. It may not be the operating system they address first, but Linux is definitely on their to-do list.
This was first published in September 2003