Problem with server bandwidth

Go you have AV on those servers? Is the AV set to scan a file when it is
accessed or just modified?

AV can have a big influence on all file operations.

If you have AV on both servers then the file is probably being scanned when
it is being read and then when it is being written.

Just a suggestion.

"Gustavo Genez" <> wrote in message
news:%...
> Hello all,
>
> I have 2 Servers Dell PowerEdge 2850 installed Windows 2003 Server SP2
> connected through a 3com 3250 switch.
>
> Each server are connected to a gigabit port. My problem are coming when I
> try to copy from one server to other a large file (about 15 GB),
> monitoring my network bandwidth I found my data transfers from 140 to 190
> mbps.
>
> I change the utp cable to certified cat 6 directly connected to switch
> 3com and the problem remains.
>
> I need help to increase the data transfer between serveers because I need
> to backup some files and the time to transfer is very high.
>
> Best regards,
>
> Gustavo Genez

Hello all,

I have 2 Servers Dell PowerEdge 2850 installed Windows 2003 Server SP2
connected through a 3com 3250 switch.

Each server are connected to a gigabit port. My problem are coming when
I try to copy from one server to other a large file (about 15 GB),
monitoring my network bandwidth I found my data transfers from 140 to
190 mbps.

I change the utp cable to certified cat 6 directly connected to switch
3com and the problem remains.

I need help to increase the data transfer between serveers because I
need to backup some files and the time to transfer is very high.

Best regards,

Gustavo Genez

It may be down to the sheer speed the servers can write the data to the
physical disks. Raid 5 has slower write times than Raid 1+0. The only way to
increase the through put is alter the raid config on your servers

"Gustavo Genez" <> wrote in message
news:#...
> Thanks Ruic,
>
> For this reason I have deinstalled servers antivirus and no diferences I
> have found in the data transfer.
>
> Today I'll install an update version for the intel pro/1000 driver for
> both servers and I'll try again new tests.
>
> Best regards,
>
> Gustavo Genez
>
> El 16/02/2010 04:08 p.m., ruic escribió:
>> Go you have AV on those servers? Is the AV set to scan a file when it is
>> accessed or just modified?
>>
>> AV can have a big influence on all file operations.
>>
>> If you have AV on both servers then the file is probably being scanned
>> when
>> it is being read and then when it is being written.
>>
>> Just a suggestion.
>>
>> "Gustavo Genez"<> wrote in message
>> news:%...
>>> Hello all,
>>>
>>> I have 2 Servers Dell PowerEdge 2850 installed Windows 2003 Server SP2
>>> connected through a 3com 3250 switch.
>>>
>>> Each server are connected to a gigabit port. My problem are coming when
>>> I
>>> try to copy from one server to other a large file (about 15 GB),
>>> monitoring my network bandwidth I found my data transfers from 140 to
>>> 190
>>> mbps.
>>>
>>> I change the utp cable to certified cat 6 directly connected to switch
>>> 3com and the problem remains.
>>>
>>> I need help to increase the data transfer between serveers because I
>>> need
>>> to backup some files and the time to transfer is very high.
>>>
>>> Best regards,
>>>
>>> Gustavo Genez
>>
>>
>

Thanks Ruic,

For this reason I have deinstalled servers antivirus and no diferences I
have found in the data transfer.

Today I'll install an update version for the intel pro/1000 driver for
both servers and I'll try again new tests.

Best regards,

Gustavo Genez

El 16/02/2010 04:08 p.m., ruic escribió:
> Go you have AV on those servers? Is the AV set to scan a file when it is
> accessed or just modified?
>
> AV can have a big influence on all file operations.
>
> If you have AV on both servers then the file is probably being scanned when
> it is being read and then when it is being written.
>
> Just a suggestion.
>
> "Gustavo Genez"<> wrote in message
> news:%...
>> Hello all,
>>
>> I have 2 Servers Dell PowerEdge 2850 installed Windows 2003 Server SP2
>> connected through a 3com 3250 switch.
>>
>> Each server are connected to a gigabit port. My problem are coming when I
>> try to copy from one server to other a large file (about 15 GB),
>> monitoring my network bandwidth I found my data transfers from 140 to 190
>> mbps.
>>
>> I change the utp cable to certified cat 6 directly connected to switch
>> 3com and the problem remains.
>>
>> I need help to increase the data transfer between serveers because I need
>> to backup some files and the time to transfer is very high.
>>
>> Best regards,
>>
>> Gustavo Genez
>
>

"Chris D" <> wrote in message
news:%...
> It may be down to the sheer speed the servers can write the data to the
> physical disks. Raid 5 has slower write times than Raid 1+0. The only way
> to increase the through put is alter the raid config on your servers

Having RAID5 -vs- Raid 1+0 is not going to account to the poor performance
to the degree he is experiencing. The difference would be in fact hardly
noticed at all from a human perception, and probably not noticed at all.

The problems could be:

1. Low quality cables (he only changed one in the path, not all of them).
This may also include outside EM interference into a normally "good" cable.
2. Nic problems or Nic Driver problem
3. Poor Switch performance
4. Poor compatibly between the Switch and PC Nics concerning
negotiation,...sometimes you have to statically set the Speed and Duplex
settings,...sometimes Auto works better,...sometimes Statically set works
better.
5. Other things in the Advanced Settings of the Nic. Defaults usually work
great,...people start monkeying around with them trying to outsmart the
system and performance may die.
6. Active AV scanning the files as Ruic mentioned

--
Phillip Windell

The views expressed, are my own and not those of my employer, or Microsoft,
or anyone else associated with me, including my cats.
-----------------------------------------------------

Hello,


I have to agree with Philip. As usual, he makes some very good points.

I looked over the 3COM specs and the aggregate bandwidth is big enough (13
GBps), so I find it unlikely that there are bottleneck problems.

As Philip mentioned, check the cables, NIC settings, etc.

The switch also seems to have VLAN or Layer3 functionality so make sure it's
properly configured otherwise that could have some performance degradation
issues.

Cheers,


--
Miguel Fra / Falcon ITS
http://www.falconits.com

Hi Phillip,

Today I have tried to test the performance with newest 3com switch and I
have the same result. Poor speed over gigabit connection.

1. I bougth a cat 6 cable from a network store, this cable is
"certified" (is what they say in this store).

2. I'll change the driver to newest one to try again the network speed.

3. I have tried whith a newest 3com switch, the results are same.

4. In this case. Can you help me to find the parameters to modify for
performance tunning my network card?

5. Same to the 4th item.

6. I don't have antivirus installed on this servers, I remove the
antivius protection temporally for testing purposes.

Thanks in advance.

Gustavo Genez

El 18/02/2010 12:40 p.m., Phillip Windell escribió:
> "Chris D"<> wrote in message
> news:%...
>> It may be down to the sheer speed the servers can write the data to the
>> physical disks. Raid 5 has slower write times than Raid 1+0. The only way
>> to increase the through put is alter the raid config on your servers
>
> Having RAID5 -vs- Raid 1+0 is not going to account to the poor performance
> to the degree he is experiencing. The difference would be in fact hardly
> noticed at all from a human perception, and probably not noticed at all.
>
> The problems could be:
>
> 1. Low quality cables (he only changed one in the path, not all of them).
> This may also include outside EM interference into a normally "good" cable.
> 2. Nic problems or Nic Driver problem
> 3. Poor Switch performance
> 4. Poor compatibly between the Switch and PC Nics concerning
> negotiation,...sometimes you have to statically set the Speed and Duplex
> settings,...sometimes Auto works better,...sometimes Statically set works
> better.
> 5. Other things in the Advanced Settings of the Nic. Defaults usually work
> great,...people start monkeying around with them trying to outsmart the
> system and performance may die.
> 6. Active AV scanning the files as Ruic mentioned
>

hello,
1 service firewall not started
2 I've found that disabling "TCP Large Send Offload (IPv4)" on the virtual
switch and "Large Send Offload v2 (IPv4)" on the physical adapters solves the
problem.



"Gustavo Genez" wrote:

> Hello all,
>
> I have 2 Servers Dell PowerEdge 2850 installed Windows 2003 Server SP2
> connected through a 3com 3250 switch.
>
> Each server are connected to a gigabit port. My problem are coming when
> I try to copy from one server to other a large file (about 15 GB),
> monitoring my network bandwidth I found my data transfers from 140 to
> 190 mbps.
>
> I change the utp cable to certified cat 6 directly connected to switch
> 3com and the problem remains.
>
> I need help to increase the data transfer between serveers because I
> need to backup some files and the time to transfer is very high.
>
> Best regards,
>
> Gustavo Genez
> .
>