iSCSI is a network protocol defined to allow scsi commands over TCP/IP stack, allowing to hosts I/O block operations like a device storage attached locally. With iSCSI we’ve to difference to basic concepts: iSCSI initiator: is called the scsi client,
Create local ISO library in Xen Server
Normally in XenServer the ISO library is configured in a remotely server and shared with NFS or CIFS, but for some reasons sometimes is needed to use a local storage in the same server to use it as ISO repository
Enabling Jumbo Frames
Jumbo frames is a frame larger than the standard ethernet frame (1518 bytes). When the layer 2 frame, encapsulates to a layer 3 packet it releases the Source and MAC address (12 bytes), the ethernet type (2 bytes) and CRC
configuring MySQL Sandbox
In laboratory environments is very useful run two or more instances of MySQL for test new versions, configurations or test a master-slave replication using the same system, we can get this through MySQL Sandbox. MySQL Sandbox is a script written
syslog centralized logging
Syslog is a standard in computer networks for the register of messages provided by different technologies. It is used for the debugging messages generated by applications, security auditing or other relevant information that we need to know about our systems
Apache performance tuning
In this days I’ve to work for a little project that require the optimization for a web server, that led me to question for optimizing Apache web server to the best way, depending in different factors. With this post I’ll
Monitoring DNS queries with bindgraph
Bindgraph is a tool that allow us see the number of DNS queries of a graphical way, taking the result of the queries resolved by our DNS server registered in a log file. For this, We’ve to configure logging for
Time synchronization with NTP
NTP is a network protocol used to synchronize the time in our systems. NTP was designed and currently maintained by Dave Mills. This protocol is organized of a hierarchical way, the main server is called stratum-0, this servers has the
Test network performance with iperf
iperf is a tool to measure the bandwidth and the quality of a network link (latency, packet loss…). With iperf we have a server by default listening by the port 5001/TCP and a client that will generate traffic. You can
Making backups with rsync
rsync is a tool used for synchronize files or directories minimizing the data transfer, due to its algorithm based in the difference of the files and the data compression. rsync allow us work in a local machine and with remote