iSCSI on SUSE/openSUSE - High Availability

Linux

Audience

Public

Product

FlashBlade

FlashArray

Technology Integrations

Linux

Source Type

Documentation

iSCSI Path Redundancy Model

Failover Behavior

iSCSI/dm-multipath Failover Sequence

Failover Timing

iSCSI Failover Parameters

Parameter	Default	Recommended	Description
`replacement_timeout`	120s	20s	Time before failing over to alternate path
`fast_io_fail_tmo`	5s	5s	Time before marking path as failed
`no_path_retry`	fail	queue	Behavior when all paths fail
`polling_interval`	5s	5s	Path checking frequency

Configure timeouts in /etc/iscsi/iscsid.conf:

# Aggressive failover (faster, may cause false positives in busy networks)
node.session.timeo.replacement_timeout = 20

# Conservative failover (slower, more tolerant of network glitches)
node.session.timeo.replacement_timeout = 60

Path States

dm-multipath Path Groups

Failback Behavior

Automatic failback (default for active/active arrays):

When failed path recovers, I/O is automatically rebalanced
No manual intervention required

Manual failback (for active/passive arrays):

# Check current path states
multipathd show paths

# Force path check
multipathd reconfigure

# Manually switch path group
multipathd switchgroup <multipath_device> <group_number>

Cluster Configuration with Pacemaker

Install cluster packages:

# Install Pacemaker and Corosync
sudo zypper install -y pacemaker corosync crmsh fence-agents

# Enable cluster services
sudo systemctl enable --now pacemaker
sudo systemctl enable --now corosync

# Check cluster status
sudo crm status

Using YaST for Cluster Configuration

Configure cluster with YaST:

# Install YaST cluster module
sudo zypper install -y yast2-cluster

# Launch YaST cluster configuration
sudo yast cluster

# Follow GUI to configure:
# 1. Cluster name
# 2. Node membership
# 3. Communication settings
# 4. Resources

Shared Storage Resources

Configure iSCSI LVM as cluster resource:

# Create LVM volume group on multipath device
sudo vgcreate vg_iscsi /dev/mapper/mpatha

# Create logical volume
sudo lvcreate -L 100G -n lv_data vg_iscsi

# Create filesystem
sudo mkfs.xfs /dev/vg_iscsi/lv_data

# Add to cluster as resource using crm
sudo crm configure primitive fs_data Filesystem \
    params device="/dev/vg_iscsi/lv_data" directory="/mnt/data" fstype="xfs" \
    op monitor interval="20s"

# Verify
sudo crm status