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=’′);