Author Archives: Randy

XenServer multipath configuration for LIO targets

Posted on by Randy

XenServer multipath.conf with special support for LIO-based iSCSI targets to maximize multipath performance and ensures 100% stability. path_grouping_policy setting doesn’t seem to matter (between group_by_prio and multibus) in most basic setups. Invalid lines (as reported by XenServer 6.1) have also been removed. http://djlab.com/stuff/xs61/multipath.conf Specifically: device { vendor “LIO-ORG” product “*” path_grouping_policy group_by_prio path_checker tur getuid_callout […]

X9SCM / X9SCL Network Timeout

Posted on by Randy

Supermicro X9SCM and X9SCL main boards will lose network connection after some heavy traffic, especially on RHEL/CentOS 6. Updating BIOS and driver will not always fix this: Oct 19 18:32:49 zeus kernel: ————[ cut here ]———— Oct 19 18:32:49 zeus kernel: WARNING: at net/sched/sch_generic.c:267 dev_watchdog+0x26d/0x280() (Not tainted) Oct 19 18:32:49 zeus kernel: Hardware name: X9SCL/X9SCM […]

Add or Remove IP Bindings from IIS 7.5

Posted on by Randy

Sometimes you need to run another service on port 80 or 443, but IIS binds to every IP by default. Here’s the trick to add/remove IP’s from IIS 7.5. It cannot be done by any web GUI. netsh http add iplisten ipaddress=1.2.3.4 netsh http del iplisten ipaddress=2.3.4.5 netsh http show iplisten

Kickstart 4-disk RAID10 Recipe

Posted on by Randy

Here’s a nice recipe for a RAID10 array comprised of 4x SSD disks. Tested to work on CentOS 6 (RHEL 6). Be sure to add the discard option in fstab for Trim support. zerombr yes bootloader –location=partition –driveorder=sda,sdb,sdc,sdd clearpart –all –initlabel –drives=sda,sdb,sdc,sdd part raid.100000 –size=250 –ondisk=sda part raid.100001 –size=250 –ondisk=sdb part raid.100002 –size=250 –ondisk=sdc part […]

Orphaned databases in Cpanel

Posted on by Randy

If for some reason Cpanel’s database cache is out of sync and you can’t remove or delete non-existant databases, you can do so manually: Remove orphaned DB entries from: /var/cpanel/databases/dbindex.db Same here: /var/cpanel/databases/<username>.yaml Then execute the following: /usr/local/cpanel/bin/setupdbmap /scripts/update_db_cache

Xen 4 and Libvirt From Source on CentOS 6

Posted on by Randy

Install some prerequisites: yum groupinstall “Development Libraries” “Development Tools” yum install mercurial python-devel dev86 iasl ncurses-devel ncurses \ glib2-devel glib2 openssl-devel yajl-devel libuuid-devel libuuid \ pciutils-devel pciutils texinfo kernel-xen bridge-utils gnutls gnutls-devel \ libxml2 libxml2-devel libnl libnl-devel libxslt libxslt-devel pygtk2 xorg-x11-xauth \ xorg-x11-fonts* device-mapper* gnome-python2-gconf pygtk2-libglade dbus-x11 \ gtk-vnc-python netcf netcf-devel netcf-libs vte vte-devel Pull […]