[LU-5917] DNE II Testing: lctl set_param -P not working for some parameters?

• Type: Bug
• Resolution: Unresolved
• Priority: Critical
• Environment: Recent master, CentOS clients and servers, DNE.
• Severity: 3
• Assignee: Di Wang
• Reporter: Patrick Farrell (Inactive)

Description

In relation to our DNE II testing, I tried to set enable_remote_dir_gid on a test file system. I was able to do so with lctl conf_param, but set_param -P does not appear to work. (I believe conf_param is being phased out, though? I hope so - The error messages it gives are inconsistent and unhelpful.)

This node is the MGS and an MDS - I had previously set the value to -1 with conf_param:
cat /proc/fs/lustre/mdt/centssm2-MDT0000/enable_remote_dir_gid
-1

I then did:
lctl set_param -P centssm2-MDT*.mdt.enable_remote_dir_gid=0
[Using the same syntax as for set_param]

Even after waiting a minute or two, this didn't change the value on the live file system:
cat /proc/fs/lustre/mdt/centssm2-MDT0000/enable_remote_dir_gid
-1

I then stopped the file system - unmounting all targets - then started it again.

Unfortunately, the value is still -1:
cat /proc/fs/lustre/mdt/centssm2-MDT0000/enable_remote_dir_gid
-1

I tried without the *, with no improvement:
[root@centss02 ~]# lctl set_param -P centssm2-MDT0000.mdt.enable_remote_dir_gid=0
[root@centss02 ~]# cat /proc/fs/lustre/mdt/centssm2-MDT0000/enable_remote_dir_gid
-1

So the command appears to be failing silently. I'm not sure if this is similar to conf_param, which seemed to sometimes fail silently when the argument was incorrect, or if the argument is correct and set_param is simply not working for this parameter.

It does appear to work for max_rpcs_in_flight.

I note also that get_param is not working for this parameter:
lctl get_param centssm2-MDT*.mdt.enable_remote_dir_gid
error: get_param: /proc/

{fs,sys}

/

{lnet,lustre}

/centssm2-MDT*/mdt/enable_remote_dir_gid: Found no match

So I see two problems here: It seems something is wrong with enable_remote_dir_gid, and lctl set_param -P is failing silently.