GlusterFS – Clustered Filesystem. Start a GlusterFS server on localhost with volume name foo glusterfsd -s localhost –volfile-id foo.server.media-disk-1 -p /var/lib/glus‐ terd/vols/foo/run/server-media-disk-1.pid -S /tmp/.socket –brick-name /media/disk-1 -l /var/log/glus‐ terfs/bricks/media-disk-1.log –brick-port 24009 –xlator-option foo-server.listen-port=24009
iscsiadm – open-iscsi administration utility Discover targets at a given IP address: iscsiadm –mode discoverydb –type sendtargets –portal 192.168.1.10 –discover Login, must use a node record id found by the discovery: iscsiadm –mode node –targetname iqn.2001-05.com.doe:test –portal 192.168.1.1:3260 –login Logout: iscsiadm –mode node –targetname iqn.2001-05.com.doe:test –portal 192.168.1.1:3260 –logout List node records: iscsiadm –mode node Display …
ledctl – Intel(R) LED control application for a storage enclosures. The following example illustrates how to locate a single block device. #ledctl locate=/dev/sda The following example illustrates how to turn Locate LED off for the same block device. ledctl locate_off=/dev/sda The following example illustrates how to locate disks of a RAID device and how to …
libvirtd – libvirtd management daemon To retrieve the version of libvirtd: # libvirtd –version libvirtd (libvirt) 0.8.2 To start libvirtd, instructing it to daemonize and create a PID file: # libvirtd -d # ls -la /var/run/libvirtd.pid -rw-r–r– 1 root root 6 Jul 9 02:40 /var/run/libvirtd.pid
Understanding performance bottlenecks and fine-tuning them in a Linux system: The first thing you must know in performance fine-tuning or Linux performance monitoring is the contributors. What resources contribute to the performance of applications? If your are looking for system level performance fine-tuning, incase your server / PC is slow, this atricle still will help …
lldptool – manage the LLDP settings and status of lldpad Configure LLDP adminStatus to Receive and Transmit for interface eth2 lldptool -L -i eth2 adminStatus=rxtx lldptool set-lldp -i eth2 adminStatus=rxtx Query the LLDP adminStatus for interface eth3 lldptool -l -i eth3 adminStatus lldptool get-lldp -i eth3 adminStatus Query the LLDP statistics for interface eth3 lldptool …
fuser – identify processes using files or sockets Also see lsof which can be used to identify open files. fuser -km /home kills all processes accessing the file system /home in any way. if fuser -s /dev/ttyS1; then :; else something; fi invokes something if no other process is using /dev/ttyS1. fuser telnet/tcp shows all …
lsof – list open files Also, see fuser which serves the same purpose as lsof. You may have faced problems while unmounting a filesystem or deleting a folder in Linux. You cannot perform folder (directory) delete/move operations while it is being used. You cannot unmount a filesystem while it is being used, whether it is …
nfsstat – list NFS statistics #nfsstat -o all -234 Show all information about all versions of NFS. #nfsstat –verbose -234 Same as above. #nfsstat -o all Show all information about active versions of NFS. #nfsstat –nfs –server -3 Show statistics for NFS version 3 server. #nfsstat -m Show information about mounted NFS filesystems.
pam_tally2 – The login counter (tallying) module Add the following line to /etc/pam.d/login to lock the account after 4 failed logins. Root account will be locked as well. The accounts will be automatically unlocked after 20 minutes. The module does not have to be called in the account phase because the login calls pam_setcred correctly. …