- Specify how maxmem and minmem are used at startup, failover and
  migrate
- Add a paragraph about how to manually change the runtime memory, and
  what Ganeti will and won't do automatically as of version 2.6

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

Since instances can be started, failed over and migrated with less than
their maximum memory N+1 will use the minimum memory for verification.

Note that this accounts only for the instances being moved being
resized, and not for the ones already on the node, as ganeti will not
automatically resize other instances on the target node now when trying
to start/failover/migrate an instance.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

When using a really random "extra cpus" variable, this can overflow
(especially on 32 bit) and thus the final value can be < 0, thus the
test will fail to fail.

It doesn't make sense to test with huge values, so let's just generate
a reasonable value.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

- Report the attribute value in the hooks runtime variable.
- Use it to abort migration if not enough memory is available on the
  target node.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This will be used for now to avoid ballooning memory at live migration time.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Failover works magically after we relax the check: the start operation
will just use less memory, if less memory is available.

For migrate we need to balloon down the source memory before the
migration, if the target node doesn't have enough capacity.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This was missing before, so with the new metric (NCpus), it's a good
time to test this.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

This patch changes the allocation delta stats from RSpec to
AllocInfo. There's nothing interesting about it, but it should allow
more correct computations of Npus in hspace.

I also moved the AllocStats type alias from Cluster.hs to Types.hs
(just makes more sense).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

The current RSpec type doesn't cut it anymore (and it's used in other
places), so let's introduce a separate type for holding these
statistics.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

This will be used in hspace for proper tracking of used/pool/unavail
npus.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

Otherwise the docstrings for members take too many lines.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This is superseded now.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

Instead of always overriding, we should update the nodes's maxcpu
setting only when the option is specified. Otherwise this will be read
from the cluster or from the Ganeti constant for non-live backends.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

hspace computes the NPU (normalised CPU units) via the
(used|pool|avail) VCPU divided by the (currently cluster-wide) max
vcpu_ratio.

However, in the future we'll have variable vcpu_ratios, so we can't
the calculation as such. We temporarily change to computing the
average vcpu_ratio across the cluster, however long-term this needs to
be improved, as ∑ (Vi/Pi) ≠ ∑ Vi / ∑ Pi. In the meantime we implement
this patch to remove the use of a global mcpu variable.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

Since the iPolicy contains the vcpu_ratio now, we can remove the
per-node mCpu value (which was the initial way to set this attribute).

Furthermore, we need to re-set the hiCpu value when changing the
policy.

And of course some associated unittest changes.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

This will be "naturally" read in the JSON-based backends (Luxi/Rapi),
and we add explicit code for handling it in the Text backend.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

And remove a strange comment (the commit which introduced it,
d61df03e, doesn't explain it). Also document these new keys in
iallocator.rst.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

… and add the disk_templates/vcpu_ratio new entries. Since the default
ispecs_* are dicts, we can't compare them to none.

Additionally, add a QA test for this case (empty cluster modify).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This allows changing this value from the command line.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This adds the new parameter and changes the validation routines to
handle IPOLICY_PARAMETER value as floats. Very very ugly code :(,
should be redone much cleaner.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

As opposed to the initial situation, the PARAMETERS will be more than
just the min/std/max ispecs. Let's rename it, before re-adding the
PARAMETERS constant with a different meaning.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

With this change a new disk size can be specified when recreating disks.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

We need to loop over all node groups to apply their modification to make
sure that the new ipolicy actually affects their instance

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

If we modify the ipolicy we need to verify if any instance would now
violate the new ipolicy and warn about it. Any instance which already
violates the old one is ignored.

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

This helper will be used with the Op*SetParams and ipolicy verifications

Signed-off-by: René Nussbaumer <rn@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

The ispecs (min/std/max) are different from the other ipolicy
variables (disk templates for now, more in the future). As such, let's
rename the ispecs-disk-templates to ipolicy-disk-templates for
consistency with this logical difference.

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

While debugging an issue recently I had the pleasure of looking at a
long, single-line string of JSON data. This simple utility makes it
possible to format such data into a readable format.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Introduce the rbd disk template, which handles provisioning and
management of instance disks as block devices mapped to rbd volumes
on a RADOS cluster.

The rbd template is of type DTS_EXT_MIRROR, meaning rbd-based
instances can failover or migrate to any node, without
primary-secondary limitations.

Use of this template requires the rbd kernel driver and rbd tool
on all VM-capable nodes, as well as an operational RADOS cluster,
accessible by them.

Signed-off-by: Constantinos Venetsanopoulos <cven@grnet.gr>
Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

To use the features spice agent provides, a dedicated virtio-serial
channel must be created in qemu-kvm. The communication between the agent
and the other spice components takes place over this channel.

Signed-off-by: Guido Trotter <ultrotter@google.com>
Reviewed-by: Andrea Spadaccini <spadaccio@google.com>

… this is yet another manual serialisation of objects :(

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>
Reviewed-by: Michael Hanselmann <hansmi@google.com>

When running from git HEAD, just initialising the ipolicy when
non-existing is not good enough; we need to upgrade also missing keys,
etc.

This has downsides though, as it means we'll always 'rewrite' the
ipolicy, which might create silent data loss for unhandled changes
(e.g. key removal).

Signed-off-by: Iustin Pop <iustin@google.com>
Reviewed-by: René Nussbaumer <rn@google.com>

Before this change an assertion would fail as the resource locks weren't
actually acquired.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Guido Trotter <ultrotter@google.com>

The variable “instance” is an instance object, so to not get a
serialized version of the instance, the “name” attribute must be
used.

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>

With this patch a new option (“-M”, like dsh) is added to “gnt-cluster
command” to prepend the node name to all output lines.

$ gnt-cluster command -M uname -a | grep Linux
node18.example.com: Linux node18.example.com [...]
node19.example.com: Linux node19.example.com [...]

Signed-off-by: Michael Hanselmann <hansmi@google.com>
Reviewed-by: Iustin Pop <iustin@google.com>