Description of problem:

Disk failure prediction features does not work on RHEL8.1 with smartmontools 6.6

"ceph" command in Red Hat Ceph Storage 4.0 on RHEL8.1 failed, because "smartctl" command on RHEL8.1
(in smartmontools-6.6-3.el8.x86_64.rpm: latest version for RHEL-8) can not handle "--json" option.

-----
### RHEL-8 kernel
$ uname -a
Linux <hostname> 4.18.0-147.5.1.el8_1.x86_64 #1 SMP Tue Jan 14 15:50:19 UTC 2020 x86_64 x86_64 x86_64 GNU/Linux

### RHEL-8 has smartmontools-6.6
$ rpm -q smartmontools
smartmontools-6.6-3.el8.x86_64

$ ceph -v
ceph version 14.2.4-125.el8cp (db63624068590e593c47150c7574d08c1ec0d3e4) nautilus (stable)

### "ceph device get-health-metrics <device>" fails with "smartctl returned invalid JSON".
$ ceph device get-health-metrics <device>
{
    "20200221-053259": {
        "dev": "/dev/sdf",
        "error": "smartctl returned invalid JSON",
        "nvme_smart_health_information_add_log_error": "nvme returned an error: sudo: exit status: 231",
        "nvme_smart_health_information_add_log_error_code": -22,
        "nvme_vendor": "lsi" 
    },
    "20200221-053821": {
        "dev": "/dev/sdf",
        "error": "smartctl returned invalid JSON",
        "nvme_smart_health_information_add_log_error": "nvme returned an error: sudo: exit status: 231",
        "nvme_smart_health_information_add_log_error_code": -22,
        "nvme_vendor": "lsi" 
    }
}
-----

The root cause of this issue is that RHEL-8 does not provide smartmontools-7 such as RHEL-7.

RHEL-7 already provided smartmontools-7.0-1.el7_7.1.x86_64.rpm, whose smartctl tool can handle "--json" option.

I know that that RHBZ#1671154[1] (RFE: update to smartmontools 7.0) was already filed, however
customer can not use "Disk failure prediction feature" for a long time because it's a RFE for RHEL-8 product.

As this is not a RFE but a bug for Ceph product,
I expect Ceph engineer to work somehow on this issue.

[1] https://bugzilla.redhat.com/show_bug.cgi?id=1671154

Version-Release number of selected component (if applicable):

Red Hat Ceph Storage 4.3 on RHEL 8.1

How reproducible:

Always

Steps to Reproduce:

$ ceph device get-health-metrics <device>

Actual results:

$ ceph device get-health-metrics <device>
{
    "20200221-053259": {
        "dev": "/dev/sdf",
        "error": "smartctl returned invalid JSON",
        "nvme_smart_health_information_add_log_error": "nvme returned an error: sudo: exit status: 231",
        "nvme_smart_health_information_add_log_error_code": -22,
        "nvme_vendor": "lsi" 
    },
    "20200221-053821": {
        "dev": "/dev/sdf",
        "error": "smartctl returned invalid JSON",
        "nvme_smart_health_information_add_log_error": "nvme returned an error: sudo: exit status: 231",
        "nvme_smart_health_information_add_log_error_code": -22,
        "nvme_vendor": "lsi" 
    }
}

Expected results:

$ ceph device get-health-metrics <device>

output information with any errors

Additional info:

 This issue was filed as RHBZ#1671154 (for RHEL-8 RFE)