ISCSI Raid and Clustered File Systems
This document describes how to created a raided file system that is exported to multiple host via ISCSI.
This material is obsolete ... SCST is deprecated since Alpine 2.6 in favor of TCM and OCFS2 isn't available in Alpine 3.6 (Discuss) |
Raid Configuration
Very Similar to Setting up a software RAID array.
apk install mdadm
mdadm --create --level=5 --raid-devices=3 /dev/md0 /dev/hda /dev/hdb /dev/hdc
To see the status of the creation of these devices
cat /proc/mdstat
You Don't have to wait to continue to use the disk.
iSCSI Target Config
SCST is recommended over IET, due to bugfixes, performance and RFC compliance. For a detailed config how-to please look at High_performance_SCST_iSCSI_Target_on_Linux_software_Raid
Initiator Config
iscsiadm --mode node --targetname NAME_OF_TARGET --portal IP_OF_TARGET --login
This should then give you a device /dev/sda. Check by dmesg.
fdisk /dev/sda
Create a partition to use. sda1 file system type 83
Add ocfs2 tools (available in Alpine 2.3 or greater)
apk add ocfs2-tools
It can take care of starting and stopping services, copying the cluster.conf between nodes,creating the filesystem, and mounting it.
Need to create a /etc/ocfs2/cluster.conf.
This configuration file should be the same on all the nodes in the cluster. Should look similar to the following...
node:
ip_port = 7777 ip_address = 192.168.1.202 number = 0 name = bubba cluster = ocfs2
node:
ip_port = 7777 ip_address = 192.168.1.102 number = 1 name = bobo cluster = ocfs2
cluster:
node_count = 2 name = ocfs2
Load modules:
echo ocfs2 >> /etc/modules-load.d/ocfs2.conf echo dlm >> /etc/modules-load.d/dlm.conf
modprobe ocfs2 modprobe dlm
Mount ocfs2 metafilesystems
echo none /sys/kernel/config configfs defaults 0 0 >> /etc/fstab echo none /sys/kernel/dlm ocfs2_dlmfs defaults 0 0 >> /etc/fstab
Start ocfs2 cluster
/etc/init.d/o2cb start
Run the following command only on one node.
mkfs.ocfs2 -L LABELNAME /dev/sda1
Run the following command on both nodes.
/etc/init.d/o2cb enable
mount /dev/sda1 /media/iscsi1
Now you can create read/write/change on both machines to the one drive at the same time.