itdoctor (Page 40)

Put the command you want to run on this file /etc/rc.localRead More →

watch -n 1 “echo -n ‘Apache Processes: ‘ && ps -C apache2 –no-headers | wc -l && free -m”Read More →

Sometimes there can be so many frozen mails in the Exim mail queue. To know the number of frozen mails in the mail queue, you can use the following command exim -bpr | grep frozen | wc -l In order to remove all frozen mails from the Exim mail queue, use the following command exim -bpr | grep frozen | awk {‘print $3’} | xargs exim -Mrm You can also use the command given below to delete all frozen mails exiqgrep -z -i | xargs exim -Mrm If you want to only delete frozen messages older than a day, you can try the following exiqgrepRead More →

If you run a replicated MySQL setup and have a master failure, you may see the following error in your error log. [ERROR] Error reading packet from server: Client requested master to start replication from impossible position ( server_errno=1236) At this point your slave will not be replicating and you will need to recover from the situation. But why did it occur in the first place and what does it mean to your data integrity? Why it occurs This error will occur if the master stops unexpectedly. This could be as a result of a hardware failure (like a disk error) or a power loss.Read More →

How to fix MySql Replication Error 1236 We have some websites that use two database servers in master-master replication. Recently one of the servers died and had to be resurrected. (They are cloud based and SoftLayer doesn’t seem to have their cloud-based offering thing nailed down, yet. Every week one of them will go down and be unresponsive until tech support does some magic.) After one of the servers was brought back up the other server would not connect. It “Slave_IO_Running: No” and “Seconds_Behind_Master: null” which means it was not playing nicely. First, I went to the MySql log files, which for this server isRead More →

When you connect your IPAD/IPHONE to the computer, you used to be able to see photos under DCIM folder , now it’s blank. It’s because your iphone is locked , this is to prevent someone copying your data when they don’t know your ipad/iphone password. How to fix? If your ipad/iphone is connected to the PC already , disconnect it. Unlock the phone connect to the PC again – make sure that your iphone/ipad is in unlock status.Read More →

just run “runlevel” , it will tell you what level the system is running. It’s good for chkconfig utilities.Read More →

When you finish installing Ubuntu , you see that there is no network card when running “ifconfig” , or checking /etc/network/interfaces , but you see there is no info for your network card. lspci -nn | grep -i net The following command will show a list of ethernet card available in your Ubuntu box. The output may look like this 09:00.0 Ethernet controller: Broadcom Corporation NetXtreme BCM5761e Gigabit Ethernet PCIe (rev 10) If you see the result, that means the network card has been recognized by your OS , then you just need to configure it you can add these line to bring that interfaceRead More →

Your new apache2.conf may looks like this. How to fix? you need to move ServerLimit above MaxClients StartServers 50 MinSpareServers 20 MaxSpareServers 70 ServerLimit 384 MaxClients 384 MaxRequestsPerChild 0 You also need to stop apache completely and restart it , don’t just restart with graceful.Read More →

The dependency problem occurred while installing subversion package on Linux CentOS/Red Hat with installed cPanel: Missing Dependency: perl(URI) >= 1.17 is needed by package subversio To fix this: edit file /etc/yum.conf and remove perl* from exclude sectionRead More →