topic Re: Critical VSFTP Problem in Operating System - Linux

Critical VSFTP Problem

hamidr — Wed, 27 Aug 2008 05:36:58 GMT

Hi dear itrc members.
I have an environment in which I'm running VSFTP on two bl35 servers running rhel4 u4.
And our organization has a critical software which uploads business files to the ftp server for later processing. Each file has the maximum size of 200k. Most of the times our files get corrupted. The links between branches and our data center do not show much packet lost. Can anybody help please?
I'm getting fired if I can't solve the problem.

Re: Critical VSFTP Problem

Steven E. Protter — Wed, 27 Aug 2008 11:00:56 GMT

Shalom,

I don't know why are are blaming vsftpd.

Its a very reliable, scalable product.

To be safe, remove the binaries with rpm -e and re-install if you wish.

Then maybe do a normal investigation of your system /var/log/messages /var/log/secure and try and find the source of the problem before you point fingers.

enable logging in the vsftpd.conf file to a separate file, that will help.

Also, if you are uploading binaries with the windows ftp client, it defaults to ascii and any procedures/scripts need to issue a binary command before doing the put, otherwise, corrupt file city?

So: vsftpd problem or a windows problem?

Investigate before you conclude.

I'm trying to be a little funny, but seriously what evidence do you have that its a vsftpd problem?

SEP

Re: Critical VSFTP Problem

Ivan Ferreira — Wed, 27 Aug 2008 11:37:10 GMT

>>> Each file has the maximum size of 200k. Most of the times our files get corrupted.

Â¿What kind of corruption are you talking about?

Re: Critical VSFTP Problem

hamidr — Wed, 27 Aug 2008 18:47:28 GMT

Thanks for reply. What I mean by corruption is that for example the md5 checksum of files in each side is not the same. I think it's a rare problem. Is there a better solution rather than FTP? We can even pay the price for changing the protocol or maybe mechanism.

Thanks.

Re: Critical VSFTP Problem

Ivan Ferreira — Wed, 27 Aug 2008 18:51:10 GMT

Â¿Are you using binary or ascii transfer method?

Re: Critical VSFTP Problem

hamidr — Wed, 27 Aug 2008 19:02:53 GMT

We use binary and the files are in binary format.

Re: Critical VSFTP Problem

Ivan Ferreira — Wed, 27 Aug 2008 20:25:54 GMT

Â¿How do you get the md5sum at the source system, is this a unix system also or a windows system?

Â¿Have you tried with scp instead of ftp?

Â¿Have you tested with different type of files?

Re: Critical VSFTP Problem

skt_skt — Wed, 27 Aug 2008 23:44:13 GMT

enable the ftp logging this way

â ¢ Update /etc/vsftpd/vsftpd.conf with xferlog_std_format=NO from xferlog_std_format=YES

When enabled, all FTP requests and responses are logged, providing the option xferlog_std_format is not enabled. Useful for debugging.

Default: NO

â ¢ Add log_ftp_protocol=YES at the end of /etc/vsftpd/vsftpd.conf

â ¢ Uncomment xferlog_file=/var/log/vsftpd.log on /etc/vsftpd/vsftpd.conf

Default log file is /var/log/xferlog

â ¢ Restart the vsftpd service

Re: Critical VSFTP Problem

hamidr — Thu, 28 Aug 2008 10:26:59 GMT

My clients are windows. I have the md5sums.exe and it works correct producing the exact same result for the same file as the linux md5 command.

I tested the ftp inside the data center. Does SCP check for the crc errors?

Re: Critical VSFTP Problem

Ivan Ferreira — Thu, 28 Aug 2008 12:51:29 GMT

Last time I had problems transferinf with FTP from windows to unix, was a "client ftp" problem and not server related.

For example, downloading a file with "filezilla" has problems, downloading from command line the file was downloaded correctly.

You should try doing FTP from the command line itself.

Re: Critical VSFTP Problem

hamidr — Thu, 28 Aug 2008 14:36:00 GMT

I ran a new test today. I set up two ftp servers. One using windows FTP Service and one using vsftp in linux. When I download files from windows(server) to linux(client), it is very slow and the files get corrupted. The same situation applies when uploading to linux(server) from windows(client).
If I start download files from linux(server) to windows(client), the speed is very high and the files are transfered correctly! This also applies if both the ftp server and client have the same operatin system!
Please help me. I'm really confused!

Re: Critical VSFTP Problem

Steven E. Protter — Fri, 29 Aug 2008 08:32:34 GMT

I said in my initial response, you completely mis-diagnosed the problem.

Your last results show EXACTLY what I warned you of.

1) There is nothing wrong with the vsftp server on Linux.
2) Your files get corrupted when windows ftp client or server get involved in the process.

I would suggest as a solution grade answer here that you stop using the native Windows FTP server or client.

Filezilla offers a good product that runs on Linux and Windows and uses openssh protocol which eliminates FTP altogether if you so desire.

SEP

Re: Critical VSFTP Problem

hamidr — Fri, 29 Aug 2008 15:18:05 GMT

I don't believe there's a problem with windows ftp client. I believe it's a network problem but have no idea what it is.