[Bug 1546606] [NEW] Unable to install Ubuntu 16.04 on Tuleta with multipath setup

[Launchpad Bug Tracker]

You have been subscribed to a public bug:

---Problem Description---
Unable to succeed in installing  Ubuntu 16.04 on Tuleta with multipath setup; installation hung at scanning disks
 
== Comment: #11 - Kevin W. Rudd - 2016-02-05 13:13:11 ==

It looks like the issue in this case involves an RDAC based storage
controller and I/O errors on the ghost paths.

== Comment: #23 - Mauricio Faria De Oliveira - 2016-02-17 07:48:23 ==
Hi Canonical,

This patch resolves this problem. It's been tested on 16.04.
Please consider it for uploading. 

@taco-screen-team, I believe @mathieu-tl would be assigned to this one,
it it helps.


Testing udeb package:

	~ # wget http://ausgsa.ibm.com/~mauricfo/public/bugs/bz136625/v1/disk-detect_1.114ubuntu1scsidh1_all.udeb
	~ # udpkg -i disk-detect_1.114ubuntu1scsidh1_all.udeb 

        Detect disks happened.

It is working correctly.

1) The SCSI DH modules are correctly loaded and attached (see references
count) to SCSI disk.


	~ # lsmod | grep scsi
	scsi_transport_fc      71759  1 lpfc
	scsi_dh_alua            9962  16
	scsi_dh_hp_sw           5252  0
	scsi_dh_emc             9486  0
	scsi_dh_rdac            9656  32

2) The 'Scanning disks' dialog show I/O error dialogs rather than a
silent, extremely long delay.

        [!] Partition disks

        Error fsyncing/closing /dev/sdag: Input/output error

        Warning!

	Retry
	Ignore

        <Go Back>

== Comment: #26 - Mauricio Faria De Oliveira <mauricfo at br.ibm.com> - 2016-02-17 09:20:28 ==
Quick summary.

The long delays are caused due to dmraid scanning the RDAC unowned paths
to the storage unit (seen in multipath -l as 'ghost' paths).

They happen in 2 points: during hw-detect/disk-detect and
partman/init.d/30parted (Scanning disks).

If you have multipath enabled in the installation, 
the 2nd delay doesn't happen as the individual SCSI disks (/dev/sdX) are not considered by partman, 
but the 1st delay does occur *anyway*, as /bin/disk-detect does call dmraid to scan available devices.

So, the fix is beneficial for both scenarios (multipath enabled and
disabled; e.g., user forgot to/didn't know he should enable it).

** Affects: debian-installer (Ubuntu)
     Importance: Undecided
     Assignee: Taco Screen team (taco-screen-team)
         Status: New


** Tags: architecture-ppc64le bugnameltc-136625 severity-high targetmilestone-inin1604
-- 
Unable to install Ubuntu 16.04 on Tuleta with multipath setup
https://bugs.launchpad.net/bugs/1546606
You received this bug notification because you are a member of Ubuntu Foundations Bugs, which is subscribed to debian-installer in Ubuntu.