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Linux Configure Logwatch on the Central Log Server

I'm using Logwatch for reporting on unusual items in syslog. I've central logserver up and running. All other Linux servers send logs to a remote loghost called log.example.com. How do I configure Logwatch on the central log server so that it will send daily logs messages in a single e-mail?
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Linux Convert an MP3 File to WAV Format

How do I convert an MP3 file to WAV format under Linux using a shell prompt?
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Linux Kernel /etc/sysctl.conf Security Hardening

How do I set advanced security options of the TCP/IP stack and virtual memory to improve security and performance of my system? How do I configure Linux kernel to prevent certain kinds of attacks using /etc/sysctl.conf? How do I set Linux kernel parameters?
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How do I set txqueuelen (the length of the transmit queue) length of the network card device under Linux? How do I set it for a high latency and/or a high speed network for bulk transfer from disturbing interactive traffic like ssh too much?
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Linux MTU Change Size

We've gigabit networks, and large maximum transmission units (MTU) sizes (JumboFrames) can provide better network performance for our HPC environment. How do I change MTU size under Linux?
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I've root ssh access and need to add / delete a few IP address on fly using the IPtables command via local shell script. How do I add or delete an IP address remotely over the SSH session under CentOS / Redhat / RHEL / Debian / Ubuntu Linux?
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Linux Tuning The VM (memory) Subsystem

I've fast RAID-10 disk subsystem with multiple SCSI disks. Apps running under modern Linux kernel don't write directly to the disk. They write it to the file system cache which is managed by Linux kernel virtual memory manager. Since I've high performance RAID controller I need to decrease the number of flushes. How do I tune virtual memory subsystem under Linux operating systems for better performance?
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