[lustre-discuss] Not able to start changelog in MDS

[Faaland, Olaf P.]

Hi Arnab,

Are you running "lfs changelog" on the MDS or on the client?  It needs to be run on the client.

-Olaf

________________________________________
From: lustre-discuss <lustre-discuss-bounces at lists.lustre.org> on behalf of Arnab Kumar Paul <akpaul at vt.edu>
Sent: Thursday, October 10, 2019 10:42 AM
To: lustre-discuss at lists.lustre.org
Subject: [lustre-discuss] Not able to start changelog in MDS

Hello,

I have a Lustre system with version 2.10.3 with 1 MDS and 8 OSS

On the client system: lfs df -h gives this output:

UUID                       bytes        Used   Available Use% Mounted on
scratch0-MDT0000_UUID       27.8G       61.0M       25.2G   0% /mnt/lustre[MDT:0]
scratch0-OST0001_UUID        9.2G       37.2M        8.7G   0% /mnt/lustre[OST:1]
scratch0-OST0002_UUID        9.2G       37.2M        8.7G   0% /mnt/lustre[OST:2]
.
.
.

On MDS:
$ lctl set_param mdt.scratch0-MDT0000.hsm_control=enabled
mdt.scratch0-MDT0000.hsm_control=enabled

$ lctl --device scratch0-MDT0000 changelog_register
scratch0-MDT0000: Registered changelog userid 'cl1'

$ lctl get_param mdd.scratch0-MDT0000.changelog_users mdd.scratch0-MDT0000.changelog_size
mdd.scratch0-MDT0000.changelog_users=
current index: 1
ID    index (idle seconds)
cl1   0 (56886)
mdd.scratch0-MDT0000.changelog_size=33112

$ lfs changelog scratch0-MDT0000
Can't start changelog: No such file or directory

Why does this happen? Any suggestions how to start changelog?

- Arnab Paul