[DRBD-announce] linstor-server 1.21.0-rc.1 release

Hi!

A release candidate for the next feature 1.21 release of linstor is here.
Most notable is that Linstor now automatically will add resync-after
statements
to the drbd configuration (grouped on storage pool). This should help with
faster recovery
if a whole cluster needs to reboot.
And additionally the rs-discard-granularity is also managed based on
lsblk's DISC-GRAN output.
For all additional changes see below:

## linstor-server

### Added

- query-size-info API as a better version of query-max-value-size API
- Linstor now automatically sets the resync-after property for drbd
resources, grouped by storage pools
- Added automatic rs-discard-granularity management based on lsblk's
DISC-GRAN

### Changed

- Added `zfs list` check for ZFS support to ensure that the zfs-utils are
also installed, not just the kmod
- Use recommended command sequence for SED initialization and improve error
recover

### Fixed

- Fixed DRBD size calculations with non-default peer slots
- Fixed aborting Snapshot procedure (make sure resume-io is executed)
- Fixed AutoSnapshot scheduling bug
- Fixed rollback after clearing entire PropsContainers
- Fixed that too many concurrent Snapshots led to unnecessarily long
suspend-io state
- Fixed resource getting activated instead of deactivated in shared-sp

https://pkg.linbit.com//downloads/linstor/linstor-server-1.21.0-rc.1.tar.gz


Linstor PPA:
https://launchpad.net/~linbit/+archive/ubuntu/linbit-drbd9-stack

Cheers,
Rene