We recently installed a SAN. This is an XP-512 (HDS 9960) and a software development environment using Rational's...
By submitting your email address, you agree to receive emails regarding relevant topic offers from TechTarget and its partners. You can withdraw your consent at any time. Contact TechTarget at 275 Grove Street, Newton, MA.
ClearCase. All of our tests were looking good until we went into production. Now performance trails off pretty bad under the load. We cannot see any overloading on the servers, the XP, or the network. What would you suggest we look for to isolate the real problem?
Make sure you are balancing your I/O load and your application is tuned properly.
For I/O load, you can provide quality of service for your application by using what HDS calls Priority Access and Cruise Control. These firmware-based utilities will dynamically provision path bandwidth and also check for "hot spots" (frequently accessed partitions) within the storage array and migrate the data to higher performing or less used areas.
This enables QOS for the production applications connected to the SAN. You can also get reports from the subsystem on utilization of cache and back end paths and disks. You can then manually or automatically tune the box based on the analysis.
You can also spread your access across more spindles by using smaller "LDEVS" (Logical formatted units) and creating LUNs from dispersed arrays. This will in effect take the first partition on the first four disks RAIDset and concatenate it with LDEVs from other RAIDsets across more Fibre Channels and array control processors. You can create a LUN that only spans four spindles or a LUN that spans as many as 144 spindles!
If you are unsure of how the LUN is laid out in the back end, check with your assigned HP service professional for more information. If correctly laid out, there should be no reason the storage subsystem should be the cause of performance concerns.
Editor's note: Do you agree with this expert's response? If you have more to share, post it in one of our .bphAaR2qhqA^0@/searchstorage>discussion forums.
Dig Deeper on NAS management
Related Q&A from Christopher Poelker
RAID can allow for better storage performance and higher availability, and there are many different RAID types. Read a comparison of RAID levels, as ...continue reading
SAN expert Chris Poelker discusses how to change the size of a LUN in a Microsoft cluster server environment.continue reading
SAN expert Chris Poelker compares connecting a SAN with wavelength cabling and dark fiber and discusses the pros and cons of each.continue reading
Have a question for an expert?
Please add a title for your question
Get answers from a TechTarget expert on whatever's puzzling you.