ceph.spec.in, debian/control: add smartmontools and nvme-cli dependencies
These packages are needed in order to scrape device health metrics from
devices used by OSD and MON daemons.
smartmontools' smartctl is what we use in order to scrape devices' SMART
attributes and general health metrics.
In addition, we use nvme-cli tool on NVMe devices, which fetches
vendor specific NVMe related health metrics.
Ceph rely on these tools for proper functioning of the underlying layers
of devicehealth mgr module, and other mgr modules which use devicehealth
functionality (such as diskprediction_local, telemetry, dashboard).
Essentially, most of devicehealth commands rely on proper functioning of
smartctl, otherwise they lack the device health metrics.
For example, in case smartctl is missing, the commands:
ceph device scrape-daemon-health-metrics <who>
ceph device scrape-health-metrics [<devid>]
will not be able to scrape health metrics, and the command:
ceph device predict-life-expectancy <devid>
will not provide any meaningful output (since there are no metrics).
In short, when we scrape a device by its daemon (be it an OSD or a MON):
ceph device scrape-daemon-health-metrics <who>
The devicehealth module command eventually invokes a
block_device_get_metrics() call in either osd/OSD.cc or mon/Monitor.cc,
which wraps calls to both
block_device_run_smartctl() (spawns smartctl)
block_device_run_vendor_nvme() (spawns nvme)
in common/blkdev.cc.
Minimum version requirements:
'smartmontools' is the package name, which contains two utility
programs: 'smartd' and 'smartctl'. Ceph uses the latter.
Version 6.7 of smartctl first introduced the --json option (beta), which
allows to output the metrics in a JSON format. Since then a few
adjustments were made and the feature officially launched in smartctl
version 7.0.
Since we rely on the JSON format to process the metrics, we must have
smartmontools' smartctl version >= 7.
That said, we choose not to specify smartmontools version here on
purpose, since there might be a scenario where:
We specified smartmontools version to be >= 7.
smartmontools 7 is not available yet in rhel 8 / centos 8.
A user installs via rpm ceph-osd, for example.
smartmontools will not be installed (since version >= 7 is not available
in this repo yet).
Then the user upgrades to 8.3 (which should have smartmontools >= 7),
but smartmontools will not get upgraded (since it's not installed).
In the scenario where we do not specify a version, smartmontools 6.6
will be installed, but it will be upgraded to >= 7 when a user upgrades
(and if it's a fresh installation - version >= 7 would be installed
anyway).
nvme-cli does not have a minimum version.
We use 'Recommends' for both rpm and deb packages since we do not want
the installation to fail in case of conflicts. 'Recommends' weakens the
dependency to be installed in case possible, but ignores it in cases of
conflicts with other dependencies.
It's worth mentioning that smartmontools and nvme-cli dependencies exist
in ceph-container builds.
We add them here for the cases of bare metal installations.
In the future we will add a separate package (with smartmontools and
nvme-cli dependencies) that can be installed on any node (running
rbd-mirror, rgw, mds, mgr, etc.), in order to be able to collect the
health metrics of its devices and offer their life expectancy
prediction.
projects / ceph.git / commit