Understanding RAID and NICs better
Posted on 2005-05-02
Question from Australia for all gurus out there.
I am an IT services provider in Sydney with more enthusiasm than experience. I hire experts to perform work I cannot perform, but these guys are not experts on everything.
The problem I have at the moment is that I have a client with a 2000 Server box running an application called DMS which is a finacial planning application using a SQL database on the server. They have an Intel entry level motherboard model model S845WD1-E, using 2 512mb ram modules. The database is 3.5GB in size, and the machine is burdened by giving up 800MB of RAM to the SQL server, which I assume is about as much as it could spare.
The motherboard apparently supports hardware RAID, and 2 Seagate 80GB, 7200 RPM hard drives are installed in a mirrored array, but using software RAID. My experts advise that this is madness that what could be acheived with no CPU overhead is instead being acheived with an impact on system performance.
My questions are these.
1. I wish to convert the machine from software RAID to hardware RAID. I know with hardware RAID that you can Ghost the RAIDed drives (whether striped or mirroed) to a single drive, and then Ghost back to a new array. Can you Gost a software RAID set to a single drive, and then build a new hardware RAiD array. Alternately, can you more directly simply tell the hardware RAID controller to build a new mirror array from the two software RAID drives? I suppose what I'm really asking is, "is a single drive on a software mirror RAID array exactly the same as a single drive, or is there RAID data written to each drive that complicates teh issues?"
2. The 1GB of ram fitted fills the motherboard. I wish to fit additional RAM capacity. Sub question 1, does the Intel motherboard support non ECC ram as well as the fittted ECC ram? Would it be madness to fit non ECC ram if it were possible? Is the latency of the ram critical, ie should you be safe an use slow latency 3 ram, or run top of teh line latency 2 ram? Will replacing the 2 512MB sticks with 2 1GB sticks of ram (whether they be ECC or non ECC) be likely to improve performance, given teh size of teh database?
3. This one is a doozy! The three workstations running off this server are new. They are AMD Athlon 2600CPUs on generic mobos (biostar, for example). When DMS is run and a global change of details is run, it slows the entire network, including Outlook to slow to a crawl. THe Outlook PST files are kept on the server, so I'm guessing that the global update is tying up the server, and all users are affected by its overlaoded state. It takes about 3 to 5 minutes for teh global update to occur, and for normality to return. When I changed the network card in the machine that was performing the change with a range of cards from 8139's to Intel 100pros, and everything in between, I found remarkable changes in performance. On one NIC the problem almost went away entirely, while others made it worse still. I thought I was a genius when I found teh so called fast NIC, until the third user came back from hoolidays and confirmed that although the others had benefited from the change, her performance had deteriorated badly. In other words, there was no silver bullet that solved all problems. Gains in one area caused pain in others. The DMS reseller is no help, and I'm operating beyond my comfort zone. Any ideas or test leads would be most appreciated.
I would like to address the speed issue, convert the machine to hardware RAID, and generally make things better. I just need to know how to go about it!
I'll assign top points and difficulty to this set of problems, and hope a speedy answer can be found for one or more of my problems.