Adam Salkin's questions

I'm in a small company that has offices on the east and west coasts of America and also various people working from their homes. There are Windows Servers already in the offices. I think that Microsoft Windows DFS will do what I want, but despite reading the web site, I'm really not sure, so I'm hoping that someone can confirm if it will do all the following:

(For various personnel / political reasons I know that a proposal for a Microsoft Windows system has more chance of being accepted than any *nix system)

1. Creation of a Folder so that any files in this folder will automatically be available on the servers in all the offices.
2. When anyone opens up one of these shared files on any of servers, the copies on all the servers will automatically be locked. And when they close the file, the updates automatically get copied to the file on all the servers.
3. VPN access to these folders for people working outside the offices.

Bandwidth at the main offices varies from 6 Mb/s to 20Mb/s. Files are Excel / Word / AutoCAD ranging in size from 100KB to 4MB.

Thank you.

I have just installed a server that is sending HTTP video streaming files to a Web server over NFS and I want to make sure that I have the transfer speed optimized. But I don't know what sort of read/write rates are typical so I don't know if I have already achieved close to the maximum. I understand that wsize and rsize parameters are important but I don't know what they are defaulting to and if its worth changing them.

As per the sourceforge article on NFS, I tested write speed using:

time dd if=/dev/zero of=/mnt/data/video/testfile bs=16k count=16384

And I get a Write rate of 48MB/s.
I tested this a number of times (unmounting / mounting to clear the cache) and this speed was fairly consistent.

I tested read speed:

time dd if=/mnt/data/video/testfile of=/dev/null bs=16k

And get a Read rate of 117MB/s

The ethernet switch and all cables are good for 1Gb/s and the NICs on both machines are set to use jumbo frames, (MTU=9000) and in /etc/exportfs I set the async option - speed is more important to me than perfect data integrity. Both machines are fairly standard HP Proliant's with 7.2K SATA drives (3G on one, 6G on the other). Both machines are using Linux 2.6.18. The machine sending the files is is running CentOS 5.5 and the machine receiving them is running RHEL 5.4 (Tikanga).

I'm hoping that someone who has tested a number of different systems can say whether the above figures are typical for NFS data transfer or if there is plenty of room to increase them.

I am administering a server with Ubuntu Server which is running pureFTP.
So far all is well, but I would like to know what I should be monitoring so that I can spot any potential stability and security issues. I'm not looking for sophisticated software, more an idea of what logs and process statistics are most useful for checking on the health of the system.

I'm thinking that I can look at various parameters output from the "ps" command and compare to see if I have things like memory leaks. But I would like to know what experienced admins do.

Also, how do I do a disk check so that when I reboot, I don't get a message saying something like "disk not checked for x days, forcing check" which delays the reboot? I assume there is command that I can run as a cron job late at night. How often should it be run?

What things should I be looking at to spot intrusion attempts? The only shell access is SSH on a non-standard port through UFW firewall, and I regularly do a grep on auth.log for "Fail" or "Invalid". Is there anything else I should look at?

I was logging the firewall (UFW) but I have very few open ports (FTP and SSH on a non standard port) so looking at lists of IP's that have been blocked did not seem useful.

I'm trying to write a BASH script to test if an FTP site that I own is running. I therefore want the bash script to connect to the FTP site, log in with a dummy account and redirect the output to a file that I can then grep to confirm that the login succeeded.

(I know that putting user/pass in a file is not recommended, but this dummy account is chrooted to one empty directory and can't escape to the shell, and in any case I'm the only user who can login to a shell prompt.)

I'm using the BASH shell on Ubuntu.

I created a file called "ftp-dummy" which looks like this

username  
password

And I then did this from the prompt:

adam$  ftp my.ftpsite.com  < ftp-dummy

This does not work - I don't see the normal welcome message and the output is:

Password:Name (my.ftpsite.com:adam) :

I tried removing the space between the < and the filename - same result.

If I redirect the output to a testfile, the testfile shows:

Name (my.ftpsite.com:adam): ?Invalid command

And I still get a Password prompt on STDOUT

I also tried using echo and get the same result:

echo -e "username \npassword \n" | ftp my.ftpsite.com 

I don't see why I'm not seeing the normal welcome message or why the input is not being read from the file. Any help would be much appreciated.

Thanks,
Adam