[Samba] Samba + BDE and slow speed on reading (long)

[Giovani Moda - MR Informática]

> Several posters have said that the Realtek 8168 and 8169 chips have caused 
> slow file transfers with Samba.  They solved their problem by changing to 
> another NIC.

Well, it's worth trying. I'll schedule the mainteinance with my client and 
let you guys know. Any restrictions with D-Link DGE-530T?

Thanks,

Giovani

>
> Dale
>
> Giovani Moda - MR Informática wrote:
>> Hello list.
>>
>> I'm new here, and I'm joining because I'm having a problem wich I can't 
>> figure out the solution myself. Here's what's happening:
>>
>> A Samba 3.0.24 is serving files to seven Windows XP clients. Three of 
>> those clients run an application with a BDE database. The problem is that 
>> when running this application on Samba, it gets very, VERY slow, causing 
>> it to hang. I have noticed also an unusual low speed when receiving files 
>> from the samba server over network. When sending files to the server, the 
>> speed is OK. Since the databases used by that apllication have about 50Mb 
>> each, the problem must be caused by that slow speed on receiving files 
>> from the server.
>>
>> I've twiked the configuration a bit, and came to this results:
>>
>> socket options = SO_RCVBUF=65535 SO_SNDBUF=65535 TCP_NODELAY 
>> IPTOS_LOWDELAY - Very slow on reading, fast when writing
>> socket options = TCP_NODELAY IPTOS_LOWDELAY - still slow on read, but a 
>> little better. Fast when writing
>> socket options = TCP_NODELAY IPTOS_LOWDELAY SO_SNDBUF=32768 - significant 
>> improvement when reading files, but the application still hangs due to 
>> the slow speed. Fast when reading.
>> socket options = TCP_NODELAY IPTOS_LOWDELAY SO_SNDBUF=32768 
>> SO_RCVBUF=32768 - same as above, but writing speed shows deterioration.
>>
>> Other significant parameters:
>>
>>   max connections = 50
>>   dos filetimes = yes
>>   max open files = 4000
>>   nt acl support = yes
>>   preserve case = yes
>>   strict locking = no
>>   deadtime = 15
>>   unix charset = iso8859-1
>>   display charset = cp850
>>   oplocks = no
>>   kernel oplocks = no
>>   level2 oplocks = no
>>  local master = yes
>>   os level = 64
>>   domain master = yes
>>   time server = yes
>>   preferred master = yes
>>   domain logons = yes
>>   name resolve order = wins bcast host lmhosts
>>   wins support = yes
>>   wins proxy = yes
>>   dns proxy = no
>>
>>
>> So, I went for socket options = TCP_NODELAY IPTOS_LOWDELAY 
>> SO_SNDBUF=32768 and got these results:
>>
>> Copying a 45678592 bytes throug samba, it takes from 45 to 60 seconds to 
>> transfer. The same file though FTP takes only 3.9 seconds. I know FTP is 
>> the fastest protocol and cannot be compared to samba, but still, that's a 
>> HUGE difference.
>>
>> As a desperate measure, I've copied the whole database to a XP machine, 
>> shared the folder to the network, mapped it to the other stations, and 
>> the application runs perfectly again.
>>
>> Conclusion: there's definitely a problem when reading files from samba 
>> server. It's not network related, since FTP is really fast, and when 
>> serving the database from XP, the speed is OK too. The server is a brand 
>> new Core 2 Duo E4500, 2GB RAM, 160 GB HD SATAII, NIC Realtek r8169 
>> connected to a DES-1008D Gigabit Switch. The distro in question is FC5 
>> fully updated.
>>
>> As a related topic, I've came across a situation (two times and couting) 
>> when writing files to the samba server is painfully slow. On both cases, 
>> setting SO_RCVBUF=1 has resolved the problem. I don't know why, but it 
>> did. Both times, the server was connected to a D-Link DES-1024 switch. 
>> Switching NIC's and cables had no effect, but SO_RCVBUF=1 solved it 
>> instantly. Could it be related tho this version of samba and the problem 
>> I'm having now?
>>
>> Any thoughts?
>>
>> Thanks,
>>
>> Giovani Moda
>>
>