I was preparing vCenter for an upgrade to vSphere 7 Update 3c and needed to access VAMI, however, I was not able to log in with the root credentials. Of course, I have a triple-check password.

More surprising was the fact that I was able to SSH to vCenter with credentials that failed on GUI. I tried to change the password via the SSH command passwd
After the password change, I still was not able to log in via GUI.

Good thing is that from vSphere 7 there is an option to log in to VAMI with administrator@vsphere.local . I tested that and was able to login.

This strange behavior is happening due to the vmware-statsmonitor service taking a long time to start. n this delayed duration, the applmgmt service gets marked as stopped
To resolve this issue please follow those steps:
- SSH to vCenter
- Change to
/bin/bash
if you are in appliance shell - Go to the below directory:
cd /etc/vmware/vmware-vmon/svcCfgfiles/
- Make a backup folder:
mkdir /root/backup
- Backup
applmgmt.json
andstatsmonitor.json
files:
cp /etc/vmware/vmware-vmon/svcCfgfiles/applmgmt.json /root/backup/
cp /etc/vmware/vmware-vmon/svcCfgfiles/statsmonitor.json /root/backup/
- Change permissions on the existing json files:
chmod 700 applmgmt.json
chmod 700 statsmonitor.json
- Change value of
StartTimeout
in applmgmt.json file to 600 seconds using VI editor

- Modify statsmonitor service config for vMon to set higher startup timeout (This adds a StartTimeout”: 600 to the statsmonitor.json):
sed -i '/StartTimeout/d' /etc/vmware/vmware-vmon/svcCfgfiles/statsmonitor.json
sed -i '/ApiHealthFile/a "StartTimeout": 600,' /etc/vmware/vmware-vmon/svcCfgfiles/statsmonitor.json
- Stop and start statsmonitor service explicitly:
/usr/lib/vmware-vmon/vmon-cli -k statsmonitor
/usr/lib/vmware-vmon/vmon-cli -i statsmonitor
- Reboot the VCSA:
reboot
After reboot login to the VAMI page with root credentials should be successful.
- Change permissions on the existing json files to the original permissions:
cd /etc/vmware/vmware-vmon/svcCfgfiles/
chmod 444 applmgmt.json
chmod 444 statsmonitor.json
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