6–Boot from SAN Configuration
iSCSI Boot from SAN
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Known Issue in DHCP Configuration
In DHCP configuration for SLES 12 SP3 and later, the first boot after an OS
installation may fail if the initiator IP address acquired from the DHCP server is in
a different range than the target IP address. To resolve this issue, boot the OS
using static configuration, update the latest iscsiuio out-of-box RPM, rebuild the
initrd, and then reboot the OS using DHCP configuration. The OS should now
boot successfully.
Configuring iSCSI Boot from SAN for Other Linux Distributions
For distributions such as RHEL 6.9/6.10/7.2/7.3, SLES 11 SP4, and SLES 12
SP1/2, the inbox iSCSI user space utility (Open-iSCSI tools) lacks support for qedi
iSCSI transport and cannot perform user space-initiated iSCSI functionality.
During boot from SAN installation, you can update the qedi driver using a driver
update disk (DUD). However, no interface or process exists to update userspace
inbox utilities, which causes the iSCSI target login and boot from SAN installation
to fail.
To overcome this limitation, perform the initial boot from SAN with the pure L2
interface (do not use hardware-offloaded iSCSI) using the following procedure
during the boot from SAN.
iSCSI offload for other distributions of Linux includes the following information:
Booting from SAN Using a Software Initiator
Migrating from Software iSCSI Installation to Offload iSCSI
Linux Multipath Considerations
Booting from SAN Using a Software Initiator
To boot from SAN using a software initiator:
1.
Complete the following in the adapter's preboot device configuration (
iSCSI
Boot Configuration Menu
):
a.
On all ports, set
iSCSI Offload
to
Disable
.
b.
On the Port Level Configuration page, select
Boot Mode
, and then
press ENTER to select
iSCSI (SW)
.
2.
Configure the initiator and target entries.
3.
Mount the OS ISO image.
4.
Install the OS on the iSCSI disk over L2. Follow the instructions that apply to
your specific distribution.