Gigabit Switching Increased Data Transfer
i have a network of roughly 30 users. we have 3 windows 2003 servers all gigabit capable. we are running (2) 24 port Linksys 10/100/1000 full gigabit switches. I am having periodic "outlook is retrieving data from the exchange server" messages coming up and our file based backup to another server (50Gb) is taking 10 hours to copy. i'm wondering if the cheap $400 gigabit switches just aren't cutting it with the increased traffic of late...does anybody know why some full gigabit switches (like cisco) are 5 and 6k and the linksys is $400? haha...
anybody have a recommendation on a good solid powerhouse switch for full gig? i have a few HP procurves installed at other clients and they seem great but i've never implemented a full gig solution with procurve.
anybody have a recommendation on a good solid powerhouse switch for full gig? i have a few HP procurves installed at other clients and they seem great but i've never implemented a full gig solution with procurve.
rindi
If the switches are manageable, set those ports that connect to the server's 1GB NIC's to 1GB/Full Duplex, and do the same for the NIC's of the servers. Don't set them to autonegotiate. That should ensure you get the best speeds. All other ports should be set to auto, as well as the NIC's of the PC's.
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Thanks for the response tidal1...your answer is more the response i'm looking for. If you don't mind what seems to me a stupid question...what is the definition of port density?
i've just noticed a few of my servers on 1gb connections just seem a hell of a lot faster than others at 1gb. have you seen nic's play a roll...some better than others?
i've just noticed a few of my servers on 1gb connections just seem a hell of a lot faster than others at 1gb. have you seen nic's play a roll...some better than others?
Let's start by breaking this into two parts. The outlook issue can be attributed to the mail profile being setup as "cached mode". I have a gigabit connection to my fiber backbone and I still receive this. It is the exchange server causing my "retrieving outlook data" because I am in cached mode. If I work online and do not use cached mode, this problem goes away.
As for the backup, what software are you using (ntbackup, CA Arcserve, backup exec, etc.)? I have seen this problem before. I run backups and it is usually the software causing the issue, not the network. A good test for this is to take the slow server (in this case the file server) and create a twisted wire connection directly to the other server backing it up (this applies if it is feasible given your office/use requirements). I did this with one of our servers and the throughput was the same. I basically eliminated the latency from the routers/switches.
If you are looking to migrate into much larger switches that are designed for business use, then tidal1 had great info for you to start looking around.
As for the backup, what software are you using (ntbackup, CA Arcserve, backup exec, etc.)? I have seen this problem before. I run backups and it is usually the software causing the issue, not the network. A good test for this is to take the slow server (in this case the file server) and create a twisted wire connection directly to the other server backing it up (this applies if it is feasible given your office/use requirements). I did this with one of our servers and the throughput was the same. I basically eliminated the latency from the routers/switches.
If you are looking to migrate into much larger switches that are designed for business use, then tidal1 had great info for you to start looking around.
ASKER
i appreciate that itquestions...to answer your questions:
i believe the outlooks having the issue are not in cached mode. i tend not to use that unless on a mobile pc. in fact i know this problem exists on a network without cached mode because i've actually experienced it on several pc's in my own office and we're running a cheaper linksys 24 port gigabit switch?
regarding the backup we use BackupAssist which is just a pretty overlay for NTBackup. We find it works quite well but could be causing the sluggish performance. i do have one clients server backing up 70Gb in 10 hours and another backing up over 90Gb in 10 hours using the same version of backupassist. The slower client is using a higher-end linksys gigabit switch and the faster is using an HP procurve 10/100 utilizing the (2) gigabit ports off to the side. Would you think the HP procurve with it's gigabit ports off to the side are running faster than the linksys full gig switch?
the direct connect idea is an interesting approach. i wonder if you could put fiber cards or something sweet like that in both servers and dedicate them to each other to dump the data back and forth? anybody ever tried such?
i believe the outlooks having the issue are not in cached mode. i tend not to use that unless on a mobile pc. in fact i know this problem exists on a network without cached mode because i've actually experienced it on several pc's in my own office and we're running a cheaper linksys 24 port gigabit switch?
regarding the backup we use BackupAssist which is just a pretty overlay for NTBackup. We find it works quite well but could be causing the sluggish performance. i do have one clients server backing up 70Gb in 10 hours and another backing up over 90Gb in 10 hours using the same version of backupassist. The slower client is using a higher-end linksys gigabit switch and the faster is using an HP procurve 10/100 utilizing the (2) gigabit ports off to the side. Would you think the HP procurve with it's gigabit ports off to the side are running faster than the linksys full gig switch?
the direct connect idea is an interesting approach. i wonder if you could put fiber cards or something sweet like that in both servers and dedicate them to each other to dump the data back and forth? anybody ever tried such?
They do make fiber cards for computers, but I have never tried them.
Dedicated ports would always run faster than shared ports. Wow, 70Gb in 10 hours would be torture. I have used other backup utilities that allows an average throughput of 1.1Gb/minute minimum. Have you tried a different backup utility? That may be something to consider in the future.
Back to the outlook issue. On the exchange server, can you take a look at the network utilization and see if there is excess chatter? Also, take a look at how much cpu the information store is using. If the information store is maxing out the cpu (we had this issue once before because of corrupted mail stores), then the exchange server cannot allocate enough resources for user requests.
I would try using a network monitoring utility to see how much traffic is going across your network (one example is bwmonitor --- http://www.bwmonitor.com/). I have used this and it works well.
Dedicated ports would always run faster than shared ports. Wow, 70Gb in 10 hours would be torture. I have used other backup utilities that allows an average throughput of 1.1Gb/minute minimum. Have you tried a different backup utility? That may be something to consider in the future.
Back to the outlook issue. On the exchange server, can you take a look at the network utilization and see if there is excess chatter? Also, take a look at how much cpu the information store is using. If the information store is maxing out the cpu (we had this issue once before because of corrupted mail stores), then the exchange server cannot allocate enough resources for user requests.
I would try using a network monitoring utility to see how much traffic is going across your network (one example is bwmonitor --- http://www.bwmonitor.com/). I have used this and it works well.
ASKER
i will do that...that makes sense. yeah interestingly enough the same data takes an hour and a half using the our new 200/400 LTO Dell Tape Drive...it rocks...but the file based backup is just to slow. i am really liking the file based however because unless the building burns down we can have it restored and going much faster than dealing with the tapes and i can sleep better knowing i have several copies sitting out there.
When I refer to port density I'm refering to number of ports to plug a device into. The Cisco 500 series of switches don't support more then 24 total ports (density by my definition).
Good luck
Good luck