Where's the bottleneck in this server?

I

InorganicMatter

[H]F Junkie
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Oct 19, 2004
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Note to the mods: it'd be nice if I could put this in that Enterprise forum we never got. ;)

I've got a file server that is serving roughly 35 people. It's slow, horribly slow. Specs:

2x 3GHz Intel Xeons
4GB DDR-400
Adaptec 2810SA SATA RAID Controller
8x 80GB Hitachi SATA drives in RAID-5 on said controller
3x Intel Pro/1000MT NICs in network cascading (effective 3Gb of bandwidth)

It's slow. Terribly slow. Takes forever to copy stuff on/off it during the peak of the work day. I know it's a problem with too many people accessing it at once, because if you are on in the early morning or late night it's really fast. Where's the bottleneck? I want to think it's the drives, since they are only simple 80GB drives with 8MB of cache, I think they are intended for a desktop environment. Am I right? What do you suggest I replace? I'm going to start with upping the memory to 8GB, but I still think I'm limited at the disk I/O. Help me here, my boss thinks I'm clueless on this project.
 
TheMostWantedPolishTwin said:
your post would fit even better in the Networking & Security forum, which we do have here ;)

Well you failed to provide info even more important than hardware specs - what kind of services run on this server...?
Click to expand...
It's a file server; it's got Windows 2000 Server and the sharing service, that's it.
 
The hard drives are only part of the problem. I would speculate, if many users are trying to copy large files simultaneously, the problem lies with the RAID 5 array as well. Instead of using a single 8 drive RAID 5 array, you may consider using multiple mirror arrays (or possibly RAID 10). Then, split up the shared files up among the multiple drives. From my experience, a RAID 5 array works much like a single hard drive. While RAID 5 adds redundancy and maximum throughput, it does not work well for multiple file transfers. By splitting up the workload, your hard drives would provide a much higher throughput. Then again, I could be completely wrong…
 
Yes and no on the RAID5 array. While it is treated as one large disk, it's overall I/O is increased by writing to multiple disks simultaneously. The main problem with RAID5 is that unless you have a super great controller card, you will see significant performance bottlenecks because of the parity calculation as it writes everything to the array.

You may want to look into upgrading that array controller to something with more than 64MB of cache if you are really beating the crap out of this file server.

I would lean toward the network being the bottleneck. Your server may have 3 NICs teamed for Load Balancing but that doesn't mean much since the server can still only process one request at a time. It means even less if the rest of your clients are talking at 100 MB which is really more like 20-30MB under ideal conditions. The type of network hardware you have setup will also affect performance. For instance, are all the computers plugged into a switch or a hub? A hub will kill network bandwidth when there is too much traffic. If it is a switch, is it managed? If so, check out the port configs to see how many of those clients are truly negotiating at 100/full and which are having issues and running at 10/half.

Please post specs of not only the server, but the network and clients as well.


I just had another thought... anti-virus. I'll bet you have a scanner setup on this server that is actively scanning ever file that is read/written to the box. Under heavy load, this is going to cripple your performance. To test this, shut it off for a bit and see if your performance improves. If it does, sit down and work on your exclusion list to tweak your servers performance. If it was me, I would only scan the C: on the system and completely disable scanning on the array. The local hosts will take care of scanning the files as they are accessed.
 
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