Berry van Sleeuwen
2002-Oct-16 18:37 UTC
[Samba] Transfer rate on NT/XP/2000 with service pack 6a
Hi SAMBA, This is not quite a remark on SAMBA, more a report of a problem that is not related to SAMBA. However it could be of concern to your developers team. At our company we recently (last week) installed two new fileservers. The next thing we got was a very strange effect. The configuration: - Two fileservers, running (i believe) Windows 2000, with service pack 6A and included all service and patches currently available. - Two servers running Sterling Connect Direct. - Several other NT servers and workstations running NT 4 with servicepack 6. The Connect Direct servers are used to transfer data from and to our mainframe. The data can be located anywhere on a fileserver within our LAN or even WAN. After the new fileservers were installed the data-troughput dropped from several MB per second to bytes per second. A file download from mainframe to LAN would take some seconds before, now it takes up to hours! However, an upload was no problem. We checked the connect direct servers and discovered that the only servers it would have a problem with were in fact the two new ones. No problems were found when the data was transferred to the old servers or workstations. Also when the files were transferred to the Connect direct servers itself there was no problem. When the file afterwards was to be moved from the CD-server to the LAN normal speeds were recorded. So only when transferring directly from mainframe to LAN, by the CD-server, was a problem. At this stage we have received a message that the SMB protocol has been changed. It was discovered that it had a serious security leak that has been 'repaired' with the most recent fixes. We don't know what has changed, but it seemds that there is some kind of checking on the transfer that will lead to a serious drop in the transfer rates. My guess would be that if there is a non-windows environment involved in the datatransfer it will be treated in a 'very safe' way, and by this it cannot get a normal transfer rate. Actually, well I'm a mainframe guy, I don't want to know what has been changed. To me, windows is one giant security leak but anyway. I imagine this could be of interest for those who have an interrest in the SMB protocol. If this is true for a mainframe connection it very well could be true for some *nix connection too. We do not use unix in our shop, nor SAMBA so we can't test this one. At home I've used SAMBA a few times to get my Linux connect to my Windows system. It has never been setup properly, I only used it to get some files from my windows to my linux without using FTP. Regards, Berry van Sleeuwen.