Redhat Tech Exchange 2015

Due to the recent tragic events last week in Bangkok, the RHTE organization is doing an effort to relocate the event out of Bangkok and Thailand to ensure your safety. While we have continuously monitored the news and travel advisories from various sources, we decided that the situation at this moment is not stable enough to proceed with the current locations.

Please allow us some time to rearrange the location and work on the logistics. In case of any questions please contact the staff atrhte@circusmax.com for more information. For now, please suspend all travel planning until you recieve a confirmation message with the new location and additional instructions.

more info @ http://redhat.events/rhte/

update: event was relocated to Ho Chi Minh City Vietnam

DevOpsDays Singapore

Reserve your ticket @ http://www.devopsdays.org/events/2015-singapore/registration/

Linux RAID Devices

To list disk

parted -l |grep sd #sd-scsi disks

Use in command line

parted parted /dev/sdb print

Creating a raid5

mdadm -Cv /dev/md0 --level=5 -n3 /dev/sdb1 /dev/sdc1 /dev/sdd1 mdadm --detail /dev/md0

Use the command below to create a copy of the partition of an existing disk then format then use mdadm --add to the array.

sfdisk -d /dev/ |sfdisk /dev/ Example: sfdisk -d /dev/sda | sfdisk /dev/sdb

Fail a disk

mdadm /dev/md0 -f /dev/sdb1

Remove a disk

mdadm /dev/md0 -r /dev/sdb1

Add a disk

mdadm /dev/md0 -a /dev/sdb1

Stopping md

mdadm --stop /dev/md0 

Start md

mdadm --assemble --scan

Saving mdadm config

echo 'DEVICE /dev/sd*' > /etc/mdadm.conf mdadm --detail --scan >> /etc/mdadm.conf

Removing array

mdadm -S /dev/md0 >> stop md mdadm --zero-superblock /dev/sdb1 mdadm --zero-superblock /dev/sdc1

Creating RAID 0

mdadm -Cv /dev/md0 --level=0 -n2 /dev/sdb1 /dev/sdc1

Creating RAID 1

mdadm -Cv /dev/md0 --level=1 -n2 /dev/sdb1 /dev/sdc1

Creating RAID 5

mdadm -Cv /dev/md0 --level=5 -n3 /dev/sdb1 /dev/sdc1 /dev/sdd1 --spare-disk=1 /dev/sde1