touch-packages team mailing list archive

[Scott Moser <smoser@xxxxxxxxxx>]

Martin,
 guests are just systems. People can and do  use lvm and raid in cloud guests quite commonly.  Its even defined good practice in many cases (http://docs.aws.amazon.com/AWSEC2/latest/UserGuide/EBSPerformance.html).
 
with regard to "cloud images on real hardware".  Thats explicitly what maas does.  We use the "maas ephemeral image".  Which is built starting from the cloud image.  we then install the -generic kernel inside, and a very few other packages (cloud-initramfs-dyn-netconf maas-enlist open-iscsi).  We could add mdadm and lvm2 to that list.  However, we're interested in reducing that delta rather than increasing it.

Wrt boot delays, there should not be significant boot delay (if any) in
cases where root= does not require it. Am I wrong in that assumption?

We're really looking to *reduce* deltas and "things" that we produce,
rather than create more. I would also probably at some point add 'cloud-
initramfs-dyn-netconf' and 'open-iscsi' to the cloud-image and then drop
maas-enlist above.  Then the only difference between a cloud image and a
"real system" from the point of view of a default install would be the
kernel selection.  We've even investigated if we could reasonably get
rid of that difference.

There are costs to having one image that is expected to work in all
cases, but there are also lots of benefits.

-- 
You received this bug notification because you are a member of Ubuntu
Touch seeded packages, which is subscribed to lvm2 in Ubuntu.
https://bugs.launchpad.net/bugs/1491102

Title:
  [FFE] add mdadm and lvm2 to cloud image

Status in lvm2 package in Ubuntu:
  New
Status in mdadm package in Ubuntu:
  New

Bug description:
  In order to make use of raid and lvm functionality that is being added
  to curtin, we need to have mdadm and lvm2 packages available.  curtin
  is able to install the packages, but that is less desireable than
  having them already available inside the image.

  This bug is a feature freeze exception to add mdadm and lvm2 to the
  wily cloud-image seed [1].

  == general risks ==
  Adding these packages will add ~ 5M total to the cloud image installed system.

  == mdadm risks ==
  mdadm recommends 'default-mta', and cloud-images have always been built with 'recommends by default'. So addition of this package to the cloud image means also adding an unconfigured mta (postifx). There is some discussion on this topic from ubuntu-devel at [2].

  As a point of reference here, I did a server ISO install with raid,
  and found that 'default-mta' does *not* get installed.  The installer
  must select to install mdadm but not pull in its Recommends.

  Additionally, its possible presence of this package could cause
  issues.  It installs udev rules that could misfire.  Any such issues
  encountered really should be fixed anyway, rather than just hoped to
  not be hit.

  == lvm2 risks ==
  Similarly to mdadm, lvm adds udev rules and could raise cause problems.
  As with mdadm, any such issues really ought to be fixed any way.

  == general information ==
  The reason this is proposed for inclusion into the cloud-image is 2 fold
  a.) the maas ephemeral images are created from the cloud-image.  so packages in the cloud-image are then available in the install environment for maas.  We dont want to add differences between these installation sets.
  b.) it is not unreasonable to add these packages to the cloud image.  It is not at all farfetched that someone would use lvm or raid in a "cloud" environment, so they're not entirely wasted space there.

  --
  [1] http://bazaar.launchpad.net/~ubuntu-core-dev/ubuntu-seeds/ubuntu.wily/view/head:/cloud-image
  [2] http://irclogs.ubuntu.com/2015/08/06/%23ubuntu-devel.html#t22:53

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