[Bug 1887143] Re: mdmonitor closes mdstat fd if is empty

[Mariusz Tkaczyk]

Hello,
The main issue is in development, we need to deal with module reload and descriptor handling.

The second one can be easily workaround by using systemctl service
(systemctl mdmonitor restart) instead of command line. Here error
handling is needed instead of quiet fail.

I will notify if any fix will become available.

-- 
You received this bug notification because you are a member of Ubuntu
Foundations Bugs, which is subscribed to mdadm in Ubuntu.
https://bugs.launchpad.net/bugs/1887143

Title:
  mdmonitor closes mdstat fd if is empty

Status in mdadm package in Ubuntu:
  New

Bug description:
  There was a change in mdadm to fix issue when md_mod is reloaded (not a case for ubuntu because md_mod is build-in). Commit:
  https://git.kernel.org/pub/scm/utils/mdadm/mdadm.git/commit/?id=52209d6ee1183581e148791cf6ee4d60a0193b1d

  The fix prevents mdmonitor from occupying mdstat file descriptor in there is no any mddevice available.
  As a side effect mdmonitor cannot react on md events because it is waiting in undefined resource (probably 1 which in demonize mode case is /dev/null).

  When mdmonitor is started form command line and there was one
  mdmonitor already active, error message also is omitted, because error
  is thrown after forking. As a result, unexpectedly we may got same
  same issue after array creation.

To manage notifications about this bug go to:
https://bugs.launchpad.net/ubuntu/+source/mdadm/+bug/1887143/+subscriptions