Sinan Polat


Service Pack for ProLiant (SPP) Version 2015.10.0 Direct download link

HP keeps disconnecting the connection when I am trying to retrieve the Full ISO Image of Service Pack for ProLiant (SPP) Version 2015.10.0. To spare you some time, I made a direct link. From HP: Download From (much faster and no dropping connections): *Link removed* Unfortunately I have been contacted by HP to remove the […]

Simple SSH bruteforce prevention using iptables

Since I like to learn more about scripting, I decided to write my own SSH bruteforce prevention script instead of installing a plug-and-play tool. You can run the script manually or have it run every hour or so using crontab. As root, create a new directory for the script and files, name it for example […]

Error: The monit service does not respond. Refer to Parallels technical support for help.

I have Plesk 12 installed on a machine running CentOS 6, but I am not able to start Watchdog due to the following error message: Error: The monit service does not respond. Refer to Parallels technical support for help. It seems that the monitrc template is using a log location which doesn’t exist and therefor […]

hpacucli not detecting HP Smart Array Controller

In some cases hpacucli is not detecting the HP Smart Array Controller, in my case it was a HP P420 controller. => ctrl all show Error: No controllers detected. => You can solve this issue by loading the sg module: # modprobe sg You’ll see now that the controller is detected: => ctrl all show […]

MySQL crashing during startup

I just had a server on which I was not able to start MySQL. The MySQL error log shows the following: 121121 18:30:13 mysqld_safe Starting mysqld daemon with databases from /var/lib/mysql 121121 18:30:13 [Note] Plugin ‘FEDERATED’ is disabled. 121121 18:30:13  InnoDB: Initializing buffer pool, size = 8.0M 121121 18:30:13  InnoDB: Completed initialization of buffer pool […]

Plesk: Unable to connect to database: saved admin password is incorrect

Symptom: Not able to log in to Plesk Panel. The following MySQL error is shown instead of the login screen: ERROR: PleskFatalException Unable to connect to database: saved admin password is incorrect. 0: common_func.php3:150     psaerror(string ‘Unable to connect to database: saved admin password is incorrect.’) 1: auth.php3:107 ERROR: PleskFatalException Unable to connect to database: […]

Problem installing VMWare ESXi 5 on DL HP120 G7

It seems that HP DL120 G7 have difficulties with installing VMWare ESXi5 while ESXi4 is running fine. During the installation it crashes with the following error message: No place on disk to dump data. This occurs because an option in the BIOS. To fix the problem reboot your server into the BIOS and go to: […]

Solution for ip_conntrack: table full, dropping packet.

Today, I was working on a brand new  (apache) server, hosting a website with 3000 concurrent visitors. The load on the server was very low while the website was dropping network connections. I ran dmesg and the following message was repeating over and over: ip_conntrack: table full, dropping packet.   It seems that ip_conntrack keeps […]

Monitoring I/O on Linux

You can use iostat to find out disk utilization, but with iotop you can monitor the actual read/write. iotop watches the I/O usage information output by the kernel and displays it in a table of current I/O usage by processes. iotop syntax for monitoring I/O usage -o Will only show processes or threads which are […]

Spamassassin: Block / blacklist an e-mail address

I am running Postfix on my Debian Linux server and using spamassassin to detect spam e-mails. However sometimes you just want to block all incoming e-mail from a domain name or e-mail address. With option ‘blacklist_from‘ in spamassassin this is very simple and useful. Locate your spamassassin configuration file and open it with your text […]