Currently, troubleshooting DRBD problems involves a manual process of going
backwards from the DRBD device to the instance that owns it.

This patch adds a weak (i.e. not guaranteed to be correct or up-to-date)
cache of device to instance. The cache should be, in normal operation,
having correct information as the only time when devices change paths
are when they are started/stopped, and the code in backend.py adds cache
updates to exactly these operations.

The only drawback of this implementation is that we don't fully update
the cache on renames of devices (we clean the old entries but we don't
add new ones). Since the rename changes the path only for LVs (and not
drbd and md), this is less of a problem as the target of this code is
debugging DRBD and MD issues.

The patch writes files named bdev_drbd<N> (or bdev_md<N>,
bdev_xenvg_...) in /var/run/ganeti (more exactly, LOCALSTATEDIR/ganeti).
The files start with 'bdev_' and continue with the path of the device
under /dev/ (this prefix stripped), and contain the following values,
space separated:
  - instance name
  - primary or secondary (depending on how the device is on the primary
    or secondary node)
  - instance visible name: sda or sdb or not_visible, the latter case
    when the device is not the top-level device (i.e. remote_raid1
    templates will have sd[ab] for the md, but not_visible for drbd and
    logical volumes)

The cache is designed to not raise any errors, if there is an I/O error
it will only be logged in the node daemon log file. This is in order to
reduce the possible impact of the cache on the block device activation
and shutdown code.

Reviewed-by: imsnah

When renaming a logical volume, we should change the dev_path (and other
internal variables) in order to be consistent.

Reviewed-by: imsnah

I forgot a pair of parentheses in that revision which break the common
case. This patch adds them.

Reviewed-by: ultrotter

If the device is unconfigured (not yet did SetDiskID for it ever), it
might have a physical_id of None. This patch fixes that case.

Reviewed-by: ultrotter

Reviewed-by: ultrotter

Currently we ignore errors on instance shutdown (on the source node)
during instance failover. We should do this only if the user gave a
command line options allowing this, as it's a dangerous thing to do.

This patch fixes this by using the same "--ignore-consistency" option
for deciding whether to continue or abort. It also expands a bit the man
page.

Reviewed-by: imsnah

The current code checks the bridge on the primary node of the instance,
but we need to check it on the destination node.

This was caught by testing failover with a down primary node.

Reviewed-by: imsnah

Reviewed-by: schreiberal

This patch moves the passing of the feedback_fn argument from the
(Exec|Chain)OpCode to the initialization of the Processor instance.

Reviewed-by: imsnah

The major is declared in the base class, we do not need to overwrite it.

Reviewed-by: imsnah

Reviewed-by: imsnah

Reviewed-by: imsnah

This patch adds three modes of disk replacement for drbd8:
  - replace the disk on the primary node
  - replace the disk on the secondary node
  - replace the secondary node

It also adds some debugging code to backend.py and increments the
protocol version for the recent changes of the rpc layer.

Reviewed-by: imsnah

This patch adds functionality to drbd8 for:
  - removing local storage
  - initializing without local storage
  - adding local storage

This is needed for the being able to replace disks for drbd8.

Reviewed-by: imsnah

This patch add code for renaming a device; more precisely, for changing
the unique_id of the device. This means:
  - logical volumes, rename the volume
  - drbd8, change the remote peer

This is needed for the being able to replace disks for drbd8.

Reviewed-by: imsnah

The two function 'any' and 'all' are copied as-is from the python 2.4
documentation for the itertools module. They are useful (and are already
builtin function in python 2.5).

Reviewed-by: iustinp

This is done in order to easy debugging of disk-related issues.

Reviewed-by: imsnah

The two calls mirror_addchild and mirror_removechild take only one child
for addition/removal. While this is enough for our md usage, for local
disk replacement in drbd8, we need to be able to specify both the data
and metadata device. This patch modifies these two rpc calls (and their
backend implementation and their usage in cmdlib) to take a list of
children to add/remove.

Reviewed-by: imsnah

This is a partially working drbd8 template type. It does:
  - add/remove
  - startup/failover/shutdown

Not working is replace disks, which needs custom code for this template.

Reviewed-by: imsnah

Currently the way we shutdown or startup disks seems to make DRBD8
unhappy. Until we rewrite the sequence of (de)activation, allow DRBD to
connect after a sb1-pri condition with no changes to the data.

Reviewed-by: imsnah

This leaves an instance's disks configured for the primary node as after
disk activation we want to start the instance anyway. As such,
_GatherBlockDevs in backend.py will need the disks configured for the
primary.

Reviewed-by: imsnah

This duplicates some code from the DRBDev class, but not very much, and
it will be expanded with the new functionality available for the 8.x
version. Currently the code is not accessible outside the module.

This patch introduces a dependency on the pyparsing module.

Reviewed-by: imsnah

The DRBDev._IsValidMeta only checks for the metadata device size. Since
this is a useful check (but not complete) for DRBD8, move it to the base
class and name it _CheckMetaSize.

Reviewed-by: imsnah

This moves the _SetFromMinor and _MassageProcData to the base class.

Reviewed-by: imsnah

Currently, the out-of-minors handling is not very good: though both MD
and DRBD functions for finding an unused minor can return None, only the
DRBD code checks for this case.

This patch improves this by making the functions _FindUnusedMinor raise
an error instead of None, and gets rid of the one manual check for the
return value.

Reviewed-by: imsnah

Since some of the methods and constants are valid for both 0.7 and 8.x
versions, we move them to the base class.

Reviewed-by: imsnah

Reviewed-by: imsnah

This is a small split of some functionality from the DRBDev class into a
base drbd class that holds just a few things, in order to make migration
to drbd 8.x easier.

Reviewed-by: imsnah

Currently, the disk types are defined using constants in the code.
Convert those into constants so that we can easily find them and check
their usage.

Note that we don't rename the values of the constants as they are used
in the configuration file, and as such it's best to leave them as they
are.

Reviewed-by: imsnah

This patch series implements the reboot command for gnt-instance. It
supports three types of reboot: soft (hypervisor reboot), hard (instance
config rebuild and reboot) and full (full instance shutdown and startup
again).

This patch contains the opcode and lu part.

Reviewed-by: iustinp

This patch series implements the reboot command for gnt-instance. It
supports three types of reboot: soft (hypervisor reboot), hard (instance
config rebuild and reboot) and full (full instance shutdown and startup
again).

This patch contains the backend and rpc part of the patch.


Reviewed-by: iustinp

Reviewed-by: schreiberal

Reviewed-by: imsnah

This patch adds a new option to the instance removal command
"--ignore-failures" that forces the removal of the instance from the
configuration even if the removal process encounters errors.

In order to be able to do this when the remote node(s) is(are) down, we
need to restrict the execution of the instance removal hook to the
master only. I think this is a reasonable trade-off (but I'm not sure).

Reviewed-by: imsnah

The node's ssh keys filenames are now provided as constants; this should
allow easier customization.

Also, the user's ssh key computing has been abstracted into ssh.py

Reviewed-by: imsnah

Reviewed-by: iustinp

This patch does the following:
  - add constants.GANETI_RUNAS = "root", which is used to compute
    the homedir (and thus the .ssh directory) instead of hardcoding
    "/root/.ssh" in backend.AddNode and backend.LeaveCluster
  - add constants.SSH_CONFIG_DIR (currently hardcoded to /etc/ssh) that
    is used in backend instead of hardcoding it (preparation for
    selecting that at ./configure time)
  - some more internal cleanup in backend.AddNode

Reviewed-by: imsnah

Currently there are a few version of "write a file safely" in the code.
This patch adds a generic function that should be able to replace all
the other versions.

The "take attributes from the target file" option, while useful, is not
implemented by this patch.

Reviewed-by: imsnah,ultrotter

Since we remove only files from DATA_DIR and not from subdirectories,
let's not walk the entire tree, a simple listdir suffices. Also switch
to utils.RemoveFile from simple os.unlink.

Reviewed-by: imsnah

Currently GetHomeDir accepts UIDs only. Enhance it to accept either a
user name or a user id, to allow for nicer usage.

Reviewed-by: imsnah