Categories Archives: Uncategorized

XenServer multipath configuration for LIO targets

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. Specifically: device { vendor “LIO-ORG” product “*” path_grouping_policy group_by_prio path_checker tur getuid_callout […]

X9SCM / X9SCL Network Timeout

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 […]

MDADM Cheat Sheet

This info is taken from here. 1. Create a new RAID array Create (mdadm –create) is used to create a new array: mdadm –create –verbose /dev/md0 –level=1 /dev/sda1 /dev/sdb2 or using the compact notation: mdadm -Cv /dev/md0 -l1 -n2 /dev/sd[ab]1 2. /etc/mdadm.conf /etc/mdadm.conf or /etc/mdadm/mdadm.conf (on debian) is the main configuration file for mdadm. After […]

DJBot Rsync Copy

rsync –progress -av –delete -e ssh root@x.x.x.x:/ root –exclude=/dev –exclude=/proc –exclude=/sys –exclude=/tmp –exclude=’*.mp3′ –exclude=’*.MP3′ — exclude=’*.sql.gz’ –exclude=djbot/logs

SQL-fu #1

Nested select with an insert to create multiple rows — used this to add admin privileges for a client in Maia for all their domains: INSERT INTO maia_domain_admins (SELECT t2.domain_id,1013 from postfix_transport t2 WHERE t2.mta_host=’′);

Remotely installing PFSense to hard drive with VGA and without CD-ROM

FreeBSD is great for certain tasks (such as firewalls and other embedded devices), but has some real shortcomings when it comes to booting from attached or remote storage. This severely complicates the installation process in some cases. In my case, I have a remote server in a rack with no CD-ROM. Pulling the server from […]