Dell Equallogic SAN HIT Kit support for SAP in Linux 11.2

[former_member362173]

Hello Everyone,

I would like to use an Equallogic SAN as storage in SUSE Linux Enterprise Server 11.2. Is the Equallogic SAN supported in Linux when using the HIT Kit to provide MPIO and snapshot support? The article from thorsten.staerk describes Equallogic SAN + Linux + native iSCSI (no mention of the HIT Kit). I understand that there are restrictions on using third party kernel modules.

My understanding is that the Equallogic MPIO driver will provide a faster, more efficient, connection to the SAN along with additional features.

References:

Playing with an Equallogic storage

http://scn.sap.com/people/thorsten.staerk/blog/2009/02/10/playing-with-an-equallogic-storage

• Thorsten describes using Equallogic with SAP on SUSE Linux Enterprise
• Thorsten uses native iSCSI drivers

How to configure Multipath using Equallogic Host Integration Toolkit (HIT) on Linux for Oracle

http://en.community.dell.com/techcenter/enterprise-solutions/w/oracle_solutions/3795.how-to-configur...

• Describes using Equallogic multipath on Linux
• Mentions that the Equallogic mpio is a combination of user mode and kernel mode binaries

Dell EqualLogic Host Integration Tools

http://www.dell.com/downloads/global/products/pvaul/en/equallogic-host-software-new.pdf

• Host Integration Tools Overview from Dell
• Support for CentOS 5.7, Red Hat Enterprise Linux (RHEL) 5.7, 6.1 and 6.2, SUSE Enterprise Linux Server (SLES) 11 SP1

Dell EqualLogic Host Integration Tools for Linux

Installation and User's Guide Version 1.2.0

• From the documentation "Installs a compatible prebuilt kernel module, if available. Otherwise, the installation script loads the Dynamic Kernel Module Support (DKMS) package and compiles the Dell EqualLogic-supplied kernel module."

EqualLogic Integration: Installation and Configuration of Host Integration Tools for Linux – HIT/Linux

• The Dell EqualLogic HIT/Linux MPIO software consists of two components:

  • 1. The EqualLogic Host Connection Manager daemon, ehcmd, which monitors the iSCSI session state and the configuration of the Linux server and PS Series group. Running in the background, the ehcmd daemon uses the Open-iSCSI management tool (iscsiadm) to add, remove, or modify iSCSI sessions to maintain an optimal number of iSCSI sessions. It also gathers information on the volume layout from the PS Series group.

  • 2. A loadable kernel module, dm-switch, which implements a new Device Mapper target to the multipath devices. Based on the volume layout on the array members, the dm-switch module routes each I/O to the optimal path within the PS Series group.

SAP Note 784391 - SAP support terms and 3rd-party Linux

kernel drivers

• The use of binary-only Linux kernel modules or drivers on the same server as SAP software is not recommended by SAP.

Thank You,

Kevin

[former_member362173]

I'll take a moment to provide an update on the solution. There were some issues with the initial configuration of the in guest iSCSI volumes. If I had to start from scratch, I would run all the storage through VMware. The last round of software updates appears to have resolved a potentially serious issue with iSCSI disconnects. iSCSI has run perfectly for two months now. I'll consider the issue resolved once I have six months without any iSCSI issues.

One remaining issue is that LVM won't initialize properly without implementing a custom init script. The init script work-around is simple and it works.

Configuration Overview:

VMware ESXi v5.5

Equallogic SAN (with v.7.0.3 firmware)

SUSE SLES v11.3

Equallogic HIT Kit for Linux v1.3