While getting an update an IT manager at the welded carbon steel tubing manufacturer Jackson Tube, we discovered a field report on the combination of Linux, Fiber Channel networks and large disk that's being installed by Beechglen. Early this year, Mike Hornsby briefed us on the basics of the setup, one designed to bring fast storage options using Storage Area Networks to 3000s. Dennis Walker at Jackson Tube supplied some specifics.
We are currently using Beechglen's Linux Fiber Optic SAN on solid state drives with Distributed Replicated Block Device (DRBD) replication, which gave us a giant increase in speed. It's very cool; they use a Linux server with SCST Target SCSI for Linux to act as a Fiber Channel SCSI device. It uses Qlogic Fiber Channel boards to connect to the HP 3000.
Our setup is in-house, using their hardware on a hosting contract with Beechglen. We have two of their SAN devices and two of their HP 3000s, one production and one development system. The SANs are connected over an Ethernet fiber converter in two different buildings 1,000 feet apart. They have set up Linux's DRBD, and so can cross-mirror the HP 3000 logical block devices.
Before they told me about their setup, I had already been investigating a similar solution with the same software but with a SCSI-iSCSI adapter. They offered what I wanted all set up and tested, and using Fiber Channel. Plus they said they had to patch MPE to work correctly, which I could have never have done.
The Linux Fiber Optic SAN doesn't have a fancy user interface, Walker added, "but having used Linux since 1992, the text configuration files and shell commands are just fine for me. Most people have them do everything and just know they have a Beechglen SAN, so it's all transparent to them."
The HP 3000 LUNs are just flat files pointed to by the SCST configuration and can be copied for one kind of backup when the 3000 is shut down, which is a super-fast backup and recovery. Although we don't back up that way, we have a base system backup of the LUN files for a quick recovery, and we do disk to disk backup using TurboStore True Online to a private volume LUN setup on a regular disk drive. Those backup files are FTP'd to our company backup servers.
The performance is radically faster. We've seen 4,000 to 5,000 logical IO's per second, compared to a couple hundred at the peak on our old Model 20 Arrays. We've been on the system for 15 months with no problems. I consult with a company in town that uses much fancier EMC arrays with Windows servers and they cannot say the same. Plus, they have lost data because of EMC problems. This solution is not nearly as fancy, but it's very simple and reliable using just regular Linux subsystems.
The vendor recommends an upgrade to an A-Class or N-Class to take advantage of native Fiber Channel. The solution uses CentOS Linux.