# Booting from a SAN with multi-pathing **URL:** \ **Category:** SLES Install-Boot\ **Created:** [May 14, 2013, 11:56am UTC](https://forums.suse.com/t/booting-from-a-san-with-multi-pathing/23967 "2013-05-14T11:56:48Z")\ **Posts on this page:** 4\ **Page:** 1
**Author:** ![John\_Gill](https://avatars.discourse-cdn.com/v4/letter/j/9dc877/32.png) [@John\_Gill](https://forums.suse.com/u/John_Gill)\ **Post date:** [May 14, 2013, 11:56am UTC](https://forums.suse.com/t/booting-from-a-san-with-multi-pathing/23967/1 "2013-05-14T11:56:48Z")
Hi, Running SLES11sp2 on an IBM x3630m4 with Qlogic HBA card and IBM V7000 SAN. The IBM V7000 SAN is configured and a chunk of 2TB disk is allocated to the server. The HBA configuration is working correctly. I boot the server with the SLES11sp2 CD and begin the installation. I configure the time and then SuSE probes the hardware and recognizes that “multi-path” hardware exists and I confirm that I want to use multi-pathing. In the “partition” section I configure/enable “multi-path” and /dev/sda changes to /dev/mapper/360050… 001. I then chop the disk into the following sections: 1 GB boot —\> /dev/mapper/360050…001\_part1 32 GB swap —\> /dev/mapper/360050…001\_part2 1.97TB root —\> /dev/mapper/360050…001\_part3 In the “booting” section I select “expert mode” and this shows that the system will boot from /dev/mapper/360050…001\_part1 and the option for MBR is checked. The system continues and finishes the installation. At the end the server needs to reboot to finalize the installation. The CMOS on the server is now set to boot from “SLES11sp2” but this fails and the installation never completes. It seems as if the MBR is never written to the SAN. Any idea or help will be appreciated. Regards John ---
**Author:** ![John\_Gill](https://avatars.discourse-cdn.com/v4/letter/j/9dc877/32.png) [@John\_Gill](https://forums.suse.com/u/John_Gill)\ **Post date:** [May 16, 2013, 5:29pm UTC](https://forums.suse.com/t/booting-from-a-san-with-multi-pathing/23967/2 "2013-05-16T17:29:17Z")
Hi, The solution ended-up being quite simple but frustrating (thanks IBM) … Trash all LUNs and SAN configs. Restart the V7000 and re-create and configure the SAN for 50GB. Install SLES11 and everything works. mmmh interesting. ☹ Delete the 50GB LUN and re-create 2.1TB LUN and try install SLES11 … failure … mmmh even more interesting. Delete the 2.1TB LUN and create 1.9TB and install SuSE and everything works. So the issue is that you cannot create a 2TB bootable LUN due to addressing. I remember in DOS there was a memory limit of 640kb because of the 8bit OS and then in Windows 95/98 there was a limit of 2GB hard drive due to 16bit OS and now with 64bit OS you have the 2TB limit. Anyway SuSE is up and running off the SAN so now I can virtualize my world (again) 🙂 ---
**Author:** ![KEVIN1](https://avatars.discourse-cdn.com/v4/letter/k/a9adbd/32.png) [@KEVIN1](https://forums.suse.com/u/KEVIN1)\ **Post date:** [May 16, 2013, 8:11pm UTC](https://forums.suse.com/t/booting-from-a-san-with-multi-pathing/23967/3 "2013-05-16T20:11:21Z")
John Gill wrote: [color=blue] > I remember in DOS there was a memory limit of 640kb because of the > 8bit OS and then in Windows 95/98 there was a limit of 2GB hard drive > due to 16bit OS and now with 64bit OS you have the 2TB limit.[/color] Yes, there was a 2 GB limit. If you may remember, when setting up NSS the maximum disk/partition size was 2 GB. The size of the pool could be larger by adding multiple such devices… It’s always nice to know about these things before starting a project rather than have them come up and bite you in the \*\*\*. 🙂 – Kevin Boyle - Knowledge Partner If you find this post helpful and are logged into the web interface, show your appreciation and click on the star below… ---
**Author:** ![laurabuckley](https://avatars.discourse-cdn.com/v4/letter/l/cab0a1/32.png) [@laurabuckley](https://forums.suse.com/u/laurabuckley)\ **Post date:** [May 21, 2013, 1:17pm UTC](https://forums.suse.com/t/booting-from-a-san-with-multi-pathing/23967/4 "2013-05-21T13:17:18Z")
Hi John, Thanks for posting your findings - I’ve found it very useful. Cheers,