Commit Graph

8 Commits

Author SHA1 Message Date
Peter Krempa
9ab36bc233 locking: Fix documentation on how automatic sanlock leases are stored
s/MD5 checkout/MD5 hash/
2016-12-19 17:28:41 +01:00
Michal Privoznik
bd3e16a3cf locking: Add io_timeout to sanlock
https://bugzilla.redhat.com/show_bug.cgi?id=1251190

So, if domain loses access to storage, sanlock tries to kill it
after some timeout. So far, the default is 80 seconds. But for
some scenarios this might not be enough. We should allow users to
adjust the timeout according to their needs.

Signed-off-by: Michal Privoznik <mprivozn@redhat.com>
2015-11-18 10:56:56 +01:00
Martin Kletzander
3de462fe9a Remove unnecessary empty first lines
Signed-off-by: Martin Kletzander <mkletzan@redhat.com>
2014-06-06 10:52:05 +02:00
Michal Privoznik
9af1b30da3 sanlock: Introduce 'user' and 'group' conf variables
through which user set under what permissions does sanlock
daemon run so libvirt will set the same permissions for
files exposed to it.
2012-10-30 10:12:10 +01:00
Daniel P. Berrange
acbd4965c4 Add support for shared sanlock leases
A sanlock lease can be marked as shared (rather
than exclusive)  using SANLK_RES_SHARED flag. This
adds support for that flag and ensures that in auto
disk mode, any shared disks use shared leases. This
also makes any read-only disks be completely
ignored.

These changes remove the need for the option

  ignore_readonly_and_shared_disks

so that is removed

Signed-off-by: Daniel P. Berrange <berrange@redhat.com>
2012-06-25 10:17:56 +01:00
David Weber
b8012ce931 sanlock: fix locking for readonly devices
Add ignore param for readonly and shared disk in sanlock
2012-05-14 16:44:09 -06:00
Daniel P. Berrange
97e4f21782 Support automatic creation of leases for disks in sanlock
The current sanlock plugin requires a central management
application to manually add <lease> elements to each guest,
to protect resources that are assigned to it (eg writable
disks). This makes the sanlock plugin useless for usage
in more ad hoc deployment environments where there is no
central authority to associate disks with leases.

This patch adds a mode where the sanlock plugin will
automatically create leases for each assigned read-write
disk, using a md5 checksum of the fully qualified disk
path. This can work pretty well if guests are using
stable disk paths for block devices eg /dev/disk/by-path/XXXX
symlinks, or if all hosts have NFS volumes mounted in
a consistent pattern.

The plugin will create one lockspace for managing disks
with filename /var/lib/libvirt/sanlock/__LIBVIRT__DISKS__.
For each VM disks, there will be another file to hold
a lease /var/lib/libvirt/sanlock/5903e5d25e087e60a20fe4566fab41fd
Each VM disk lease is usually 1 MB in size. The script
virt-sanlock-cleanup should be run periodically to remove
unused lease files from the lockspace directory.

To make use of this capability the admin will need to do
several tasks:

 - Mount an NFS volume (or other shared filesystem)
   on /var/lib/libvirt/sanlock
 - Configure 'host_id' in /etc/libvirt/qemu-sanlock.conf
   with a unique value for each host with the same NFS
   mount
 - Toggle the 'auto_disk_leases' parameter in qemu-sanlock.conf

Technically the first step can be skipped, in which case
sanlock will only protect against 2 vms on the same host
using the same disk (or the same VM being started twice
due to error by libvirt).

* src/locking/libvirt_sanlock.aug,
  src/locking/sanlock.conf,
  src/locking/test_libvirt_sanlock.aug: Add config params
  for configuring auto lease setup
* libvirt.spec.in: Add virt-sanlock-cleanup program, man
  page
* tools/virt-sanlock-cleanup.in: Script to purge unused
  disk resource lease files
2011-06-28 18:18:06 +01:00
Daniel P. Berrange
58eb4f2cbb Support loading a configuration file for sanlock plugin
Introduce a configuration file with a single parameter
'require_lease_for_disks', which is used to decide whether
it is allowed to start a guest which has read/write disks,
but without any leases.

* libvirt.spec.in: Add sanlock config file and augeas
  lens
* src/Makefile.am: Install sanlock config file and
  augeas lens
* src/locking/libvirt_sanlock.aug: Augeas master lens
* src/locking/test_libvirt_sanlock.aug: Augeas test file
* src/locking/sanlock.conf: Example sanlock config
* src/locking/lock_driver_sanlock.c: Wire up loading
  of configuration file
2011-06-28 18:07:06 +01:00