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PMTA knowledge base›Block Global›Directive§ 3.3.1.40

pmc-acct-min-free-space

Global

Free space threshold for the management console's accounting files
in the configuration this is a linepmc-acct-min-free-space unlimitedinside the block Global
A safety fuse for another product

The default is unlimited, that is, there is no safety fuse.

The line concerns a separate vendor product — the management console (PMC). The engine writes CSV accounting files for it, and when the console works properly they do not pile up: it collects them.

They start piling up when something breaks. The manual lists this directly: the console machine is down or overloaded, firewall rules prevent it from connecting, or the console was simply turned off without canceling its registration on the node.

Then the threshold decides what to sacrifice: disk space or data. Below the threshold the engine starts deleting the oldest files, freeing space for new ones.

And the caveat for which the line is set: deleted data is lost forever, and the console’s reports are left with holes.

The main trap is the default. Without a threshold files pile up until space runs out — and it runs out not only for them: the spool, the log and the node’s own accounting files usually live on the same partition.

So a fault in another product, which you may not even know about, stops the whole node. The line limits the damage to a loss of console data — which is already partly lost anyway.

The other half: the threshold does not fix the cause. It buys time, but the turned-off console or the firewall will still have to be dealt with.

What the Hub does. It does not write it — and should not: we do not use the vendor’s management console at all. No accounting files are generated for it, and nothing piles up.

The Hub gets its own accounting differently: events — through the telemetry webhook from the accounting block (which has its own limits: file size and sending interval), summaries — through “Accounting stats” from the accounting files on the node itself.

The line would become important on a node where the console was once registered and then turned off without canceling the registration: exactly the case the manual names.

Recommended values

What to set. A threshold is needed where the console is registered:

Value When
unlimited (default) the console is not used and not registered
5G and more the console works: the threshold as a safety fuse in case it fails
less the accounting files are on a separate partition, and nothing else is there

Count from what must still work when space runs out: the spool, the log and the node’s own accounting.

The default unlimited, the list of reasons files pile up, deleting the oldest ones and the caveat about irrecoverable loss are from the manual, § 3.3.1.40. The breakdown of values is ours.
Example configuration
# a safety fuse for when the console stops collecting files
pmc-acct-min-free-space 5G
Below the threshold the engine will start deleting the console’s oldest accounting files. The data will be lost forever, but the node will keep working.
yellow — — directive names, blue — blocks. They are highlighted the same way in the text of the card.
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Common mistakes and problems

what people get wrong and how it ends2 mistakes▶

Leaving the default with a registered console

§ 3.3.1.40

What it costsFiles pile up until the partition runs out of space — and the spool, the log and the node’s own accounting usually also live on it. A fault in another product stops the whole node.
How to spot itThe partition is filled with CSV accounting files, and the node has stopped accepting mail.
How to do it rightSet a threshold with a margin for what must still work, and find out why the console is not collecting the files.

Turning off the console without canceling the registration

§ 3.3.1.40

What it costsThe node keeps writing files for it, but there is nobody to collect them. The manual names this case directly among the reasons files pile up.
How to spot itThe console is off, but accounting files for it keep appearing.
How to do it rightCancel the registration on the node, not just turn off the console.
Compatibility
PowerMTA 6.0
described in the manual of this version · platform: any
The vendor does not state the first version for every directive — there is no note here. The name also appears in the 5.0 edition of the manual.
Reference data
Syntax
pmc-acct-min-free-space <size>
Values
a number with a size multiplier or unlimited
Default
unlimited § 3.3.1.40
Applying
reload, no restart needed
Queue
will not touch what is already queued
Where to write it
Global
How many times
once in the block
Everything here comes from the manual, with the section.
Inheritance
The directive is written at the root of the configuration file and applies to the whole node: the accounting files for the console are one set per instance, and the threshold cannot be split between them.
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Related directives

1 relation

Works together with

Delivered — the record everything is counted byThe same events that go to the node’s accounting are also written for the console — as separate CSV files. inference

How to check on the node
The line is read together with whether the console is registered at all:
grep -n 'pmc-acct-min-free-space' /etc/pmta/config
pmta show registration
An empty registration means the console is not connected and no files pile up for it. A non-empty one with no threshold is exactly the case the line was made for.
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What else to read

3 articles

◇What the node tells about itself and through which channelsSeven observation surfaces: the web monitor, the console in four formats, the log, accounting, accounting search, metrics and export to external analytics.◇Two inbound report processors and what to do with themBounces by message and complaints are parsed by two identically structured blocks; each has its own address list and its own pair of decisions about the message’s fate.◇Five ways for a queue to hand off a messageA queue does not have to use SMTP: it can write to a file, run a program, call over HTTP or discard.

In the Hub
Cost of a mistake
safe: a wrong value breaks nothing
Scenarios
Collect telemetry
Neighboring settings of the block Global:track-time-first-attempttime-first-attempt-hires-timestamphost-namesmtp-source-hostpostmasterAll 108 directives of the block →