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Zoning Brocade switches zoning overview
Storage area networks (SANs) are deployed at most larger organizations, and provide centralized administration for storage devices and management functions. When multiple clients are accessing storage resources through a SAN, you need a way to limit which targets and logical units each initiator can see. Typically LUN masking is used on the storage array to limit which initiators can see which logical units, and zoning is used on the SAN switches to limit which initiators can see which targets. In the next five blog posts, I plan to provide a step-by-step guide to zoning Brocade switches…
$ read more →Managing COMSTAR logical units with sbdadm
With project COMSTAR, you can present logical units to one or more hosts connected via Ethernet or fibre channel. Logical units are managed with the sbdadm utility, which has options to add, delete, list, import and modify logical units. To create a logical unit using a ZFS volume, the path to the ZFS volume can be passed to the "create-lu" option: If you would prefer to use a file instead of a volume, you can do that as well: In the example above, I used the COMSTAR thin provisioning support to create a 100GB logical unit using the file /tmp. After a logical unit is added, it can be listed with the sbdadm "list-lu" option: If you decide that a logical unit is no longer needed, you can remove it with the sbdadm "delete-lu" option: If you need to increase or decrease the size of a logical unit, you can use the sbdadm "modify-lu" option: There is also an "import-lu" option which can be used to import a volume or file into COMSTAR…
$ read more →Debugging issues with the COMSTAR fibre channel target
I recently talked about how you can turn an opensolaris host into a fibre channel storage array. The STMF framework maintains an internal trace buffer with recent activity, which can be extremely useful for debugging problems. To view the contents of the buffer, you can send the string "*stmf_trace_buf" to mdb: This will print a slew of debugging data to your screen, which can be extremely handy for solving issues.
$ read more →Turning an opensolaris host into a fibre channel storage array
The COMSTAR (Common Multiprotocol SCSI Target) project was integrated into opensolaris (Nevada) earlier this year, and provides a framework to turn any opensolaris host into a full featured SCSI target. COMSTAR's power comes from the fact that it supports several transport protocols, which currently includes iSCSI, FCOE and fibre channel. Having just purchased a Brocade 3200 and a couple of boxes for my lab, I thought I would test out COMSTAR to see how well it performs as as a fibre channel target. To get my fibre channel target up and operational, I first read through the COMSTAR administration guide and the opensolaris mailing list archives (since COMSTAR is relatively new, the list contains current issues and links to bug fixes)…
$ read more →Changing the name of a Brocade switch
When managing large diverse SAN fabrics, it is extremely important to assign a unique and descriptive name to each switch. This descriptive name provides an easy way to determine the purpose of a switch, and is also helpful when debugging problems. To change the name assigned to a Brocade switch, you can use the switchname command: Switch names should be chosen wisely, especially when dealing with large core/edge fabric topologies.
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