This error signals that the archive recording speed to disk is insufficient for the incoming video stream.

Problem

Trassir software displays the "Disk too slow" error when the buffer size in RAM allocated for video archive caching approaches the maximum allowable value,
because in case of buffer overflow some data will be lost.

The main reasons for producing this problem:
  • The total bitrate from cameras is higher than the HDD or NAS recording bandwidth;
  • Disks fail to write because of the additional read load due to viewing or exporting the archive;
  • The HDD is defective or has reduced recording speed as a result of reaching the end of its service life;

  • In the settings of the RAID array, the optimal method of data writing is not selected (no caching).

Solution

Depending on the situation and the nature of the playback problem, there are different solutions. But as a rule, all of them are aimed at ensuring that the stream manages to record correctly to the HDD.

In case the HDD has been in use for a long period of time and has high wear and tear (service life depends on many factors such as heat, load, etc.):

  1. Perform diagnostics of the drive for faulty sections, floating defects and interface errors (we recommend the free program "Victoria" or similar utilities for disk diagnostics);

  2. Reduce the stream received from video cameras (lower bitrate/resolution, change codec to a more efficient one available, increase compression parameter);

  3. Replacing a failed HDD.



When using a RAID array:

Set the RAID controller or NAS settings to Write policy with "Write Back" caching.

Basic write methods for RAID array:

Write Through -data is written directly to the disk array as soon as it is received. The RAID controller generates an end-of-operation signal only after the data has actually been written to the disks.

Write Back - data is written first to the controller's RAM cache and only then to disks. In this case, the operation completion signal is generated as soon as data is received by the controller cache.

Write Back is preferable here, because in this case writing runs faster. But be aware that if the RAID controller does not have a BBU (Battery Backup Unit), then in the event of a power failure all the data that was in the cache and did not have time to write to disk will be lost. Moreover, TRASSIR software will not recognize it, because the controller will have already reported the successful completion of the record.

For more information on RAID settings, consult this resource

Aleksandr Savkin