Using disk space in a PostgreSQL for 1C cluster

In Managed Databases, part of the disk space is reserved for service needs:

for the file system — approximately 4% of the disk volume;
for the operating system, service components, and logs — approximately 8 GB.

The reserved part of the disk space is not available for hosting databases. Take this into account when selecting a configuration lineup.

You can track disk capacity usage using disk capacity notifications and metrics. More about metrics in the Monitoring PostgreSQL clusters and nodes for 1C guide.

When a cluster disk is 95% full or more, the cluster will enter the DISK_FULL status and will be read-only. This is necessary to prevent total blockage or cluster corruption due to a lack of free space. To make the cluster read-write, clean up the disk or scale the cluster and choose a configuration with a larger disk size than the previous configuration.

Disk occupancy notifications

Disk occupancy notifications are sent to the email addresses of the Account Owner and users who are subscribed to the notification category "Services and products". Notifications are sent when the disk is 80% and 95% full.

Clear the disk

For your information

We do not recommend using the DELETE FROM table WHERE ... query to clean up the disk. This query can create large selections on large tables and store them on the disk. The remaining free space on the disk may be completely exhausted, which will lead to PostgreSQL issues and the need to restore its operation manually.

Open the transaction transaction_read_only = no and delete unnecessary data using one of the following queries:

DROP TABLE — completely deletes the table: data, structure, indexes, constraints (constraints), and triggers.
```
BEGIN;
SET transaction_read_only = no;
DROP TABLE table_name;
COMMIT;
```
TRUNCATE TABLE — removes all rows from a table. It works faster than DELETE.
```
BEGIN;
SET transaction_read_only = no;
TRUNCATE TABLE table_name;
COMMIT;
```
DELETE — deletes rows specified in the WHERE condition.