Is it safe to fill my 4tb western digital black to the max ?

[yafatana]

Will that affect the lifespan and performance of the drive or increase the chance of bad sectors and errors ? It's not my OS drive .

 

[kanewolf]

Rule of thumb has always been to leave 10% free space for a drive that is actively written. Since a disk has to do a write, then delete for many operations, the free space improves performance. As drive sizes have gotten larger, than percentage might be too conservative. I don't think I would fill beyond 95% full for an actively written disk.

 

[Solandri]

If it's just static data (e.g. you want to stuff the drive full of movies that you'll carry around), then it doesn't matter. You can fill it up to 100% without affecting the performance or longevity of the drive. The last movie you put on it may suffer due to fragmentation, but the drive being full of data won't cause any mechanical problems.

But if you plan to actively use (write to) the drive, then yeah, you want to keep about 10% of its space free. Defragmenters start to have problems and take a lot more time when you drop below about 15% free space.