The location of the equipment is important. This is especially true for small rooms where there is not much free space. The fact is that the registrar should be located so that no one bothers, and that the place is ventilated.
Cables from each camera come to the recorder. If there are a lot of cameras, then the cable bundle will be impressive, so it is advisable to set aside a separate room for the recorder.
In the case of a country house, this may be the back room, where the control center for other systems or the electrical panel is located. In the case of an office, a utility room or warehouse.
Separately, it should be said that not every hard drive is suitable for video surveillance systems. Regular computer disks are suitable, but they do not work long and often fail in the first 2-3 months of work. This is due to the fact that they are not designed for permanent recording. For video surveillance systems, it is required to use special hard drives that were originally designed for use in recorders or video servers. Such discs are somewhat more expensive, but they have been working for years.