Ceph qemu kvm performance issues in Windows (it's slow)

Here are my benchmarks. I’m comparing a Samsung EVO (on a workstation) with a Windows 7 qemu-kvm running on my Ceph cluster. Notes: Writeback caching is enabled Using VirtIO drivers ATTO Ceph Disk vs SSD Disk CrystalMark Ceph Disk vs SSD Disk HD Tune Ceph Disk vs SSD Disk Interestingly, the HD Tune benchmarks actually hit great speeds, but it took about 10 seconds of benchmarking to get there.

Streaming Errors with VLC on the Raspberry Pi

I’ve had tons of problems setting up my Raspberry Pi (specifically the first edition) for playing radio in sync over udp or rtp. I’ve managed to find a solution! I would get errors such as: @4000000056b8e5e40747ea1c [01ab9840] core audio output error: module not functional @4000000056b8e5e40748289c [b5d19f50] core decoder error: failed to create audio output @4000000056b8e5ed36fb571c [b4e001f8] http access: Raw-audio server found, mp3 demuxer selected @4000000056b8e5ee04fb0c1c ALSA lib pcm_hw.c:1667:(_snd_pcm_hw_open) Invalid value for card @4000000056b8e5ee0517276c [01ab9840] alsa audio output error: cannot open ALSA device "default": No such file or directory @4000000056b8e5ee05a916cc [01ab9840] core audio output error: Audio output failed @4000000056b8e5ee05cf3c6c [01ab9840] core audio output error: The audio device "default" could not be used: @4000000056b8e5ee05cf8a8c No such file or directory.

Nagios SSL/Connection Issue Solved

On /etc/nagios/nrpe.cfg, (remote server) comment out the following line: #allowed_hosts= They say it ignores this config line if you use xinet.d, but they are totally wrong. I used to get the “Host is not allowed to talk to us!” error because of this. The command I used to test the connection (on the host server) is: /usr/lib/nagios/plugins/check_nrpe -H <remote_server_ip>

Linux Commands and Paths for a Plesk 9 Server

This is my on-going cheat sheet of Linux commands for my Plesk server running on CentOS 5. I will keep updating this as I go on. Read more to see the list: Restarting Firewall: /etc/rc.d/init.d/psa-firewall stop /etc/rc.d/init.d/psa-firewall start Restart Plesk /etc/init.d/psa stop /etc/init.d/psa start Restart MySQL /etc/init.d/mysqld restart Optimize all MySQL databases and tables mysqlcheck -Ao -u username -ppassword (Optimize all) mysqlcheck -Aa -u username -ppassword (Just analyze) mysqlcheck -Aao -auto-repair -u username -ppassword (Analyze, repair and optimize) Run Logwatch

SMARTd Commands for SATA Drives

Show all SMART information smartctl -d ata -a /dev/sda1 -a = Show all SMART information for device. -d = Specify the device type to one of: ata, scsi, marvell, 3ware (ata is selected above). /dev/sda1 = The drive. Run a self-test smartctl -d ata -t offline /dev/sda1 smartctl -d ata -t long /dev/sda1 Output self-test and other log results smartctl -d ata -l selftest /dev/sda1 smartctl -d ata -l error /dev/sda1 smartctl -d ata -l selective /dev/sda1 smartctl -d ata -l directory /dev/sda1 Output all options