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visits member for 2 years, 4 months
seen Oct 3 at 23:31

I am M.Sc graduate of Computer Architecture at University of Tehran, Tehran, Iran. I enjoy learning/helping from/to others.


Dec
25
comment Execution time differs for different users
@JohnSiu BATCH runs the R in non-interactive and reads from a file. Anyway, I guess the problem is about some environment variables in bash. Many thanks.
Dec
25
comment Execution time differs for different users
@JohnSiu I have no idea! Unfortunately, it is the R application not mine.
Dec
24
comment Execution time differs for different users
I've tracked the strace for root and john. The outputs are the same (expect the process-ids), but john stalls on wait4. root continues and prints a few lines until the end of R execution. I cannot dump all the log here in comments, but just where john stalls, the root user continues and calls rt_sigprocmask, rt_sigreturn, rt_sigaction, read, and exit_group functions.
Dec
24
comment Execution time differs for different users
Many thanks! very interesting, it hangs and the last printed line is wait4(-1, . So I should see what is the wait4.
Dec
24
comment Execution time differs for different users
Thank! But no luck! root and john have the same limitations (added into the question). Any other idea? :(
Dec
24
comment Execution time differs for different users
But what kinds of limitation can be the reason?
Nov
24
comment Ubuntu webserver is out of space
can you show the size of directories under /? use cd / ; du --max-depth=1 -h.
Nov
13
comment Linux: Finding the system processes which are at the top
Fantastic! Just what I wanted! Thanks a lot :)
Nov
13
comment Disk speed test linux
It looks the hdparm uses dd in underlying too. Thanks!
Oct
8
comment Does 'ssh <remote> -t <command>' has a timeout? killed by Signal 15
Thanks. Then should I run the job as ssh remotenode -t "screen -S ServerFault /path/to/myjob &> /path/to/log " ?
Sep
28
comment Block brute-force attack using lastb and iptables
I should mention that its couple of days I am running this script on my server every 20 minutes on my server. It works fine and has detected ~9 attacker from around the world.
Sep
25
comment ftp server to restrict 'get' and 'ls'
What kind of service this FTP server offers? If it is write only, you can change the permission of FTP sub-folder to 522 to achieve what you want.
Sep
24
comment Block brute-force attack using lastb and iptables
@lain: No. Why should this happen? My system's RSA key is stored in the authorized_keys on the server. Also, there is a threshold for the number of failed retires from specific IP. The threshold is set tresh=10 and can be larger to detect a brute-force attacker.
Sep
24
comment How to install Windows on a Server without CD/DVR?
Can you boot from flash?
Sep
24
comment Block brute-force attack using lastb and iptables
My system is trusted to server and It connects through SSH passless connnection and would not be included in lastb log anyway. The script only blocks the last broken SSH logins not successful ones. +1 for Fail2ban. It looks interesting. Thanks.
Sep
23
comment Finding latest successful logins and failed attempts to a CentOS server
+1 for the lastb
Sep
22
comment Finding latest successful logins and failed attempts to a CentOS server
This thread is moved from Stackoverflow after I asked the question in Serverfault. Here is the threads discussing the second question.
Sep
22
comment Reporting Penetration Attempts to My Server
Thanks. I am hacking around OSSEC and it seems this is my solution. It gathers various log files (stated by @Toqeer) and integrates them.
Sep
22
comment Finding latest successful logins and failed attempts to a CentOS server
It is actually the answer to my first question. I'll ask the second in ServerFault. Thanks.
Aug
13
comment VMWare ESXi datastore disabled while the system is up
You are right. I rebooted the system manually and forcibly. Now everything works fine.