QoE Stor uses several folders for storage:

• /var/qoestor/backend/dump – temporary data received by receivers is stored here. After loading into the database, this data is deleting.
• /var/lib/clickhouse/ - so called DEFAULT disk. This is where the database schema and data (raw and aggregated logs) are stored.
• /var/lib/clickhouse-hot/ - the so-called HOT disc.
• /var/lib/clickhouse-cold/ - the so-called COLD disc.

HOT and COLD drives are used when you need to reduce the cost of storage.

DEFAULT must be super fast (NVMe SSD, for example) in order to receive data from DPI, store it in the database in a raw log and aggregate (form an aggregated log).

On a HOT disk, you can store an aggregated log for 1-2 weeks. A HOT disk must also be an SSD in order to build reports quickly.

Old data can be stored on the COLD disk. COLD can be a SATA HDD disk, because reports on old data are rarely built and data can be stored on a slow disk.

How to physically partition directories by disks, see the section Setting up storage on a separate disk