I built a NAS with a BananaPi and a SATA hard drive. The OS is Bananian (Debian 8/Jessie). I want to put the harddrive into standby mode using
For some reason this only works, when the hard drive (partition) is not mounted. If i mount it with
-o noatime and execute
hdparm -y it does not go into standby.
I also tried different values for
hdparm -B (127, 128, 254, 255) without any luck.
Looking at iotop and dstat I can see that there is something constantly writing to the harddrive.
Total DISK READ : 0.00 B/s | Total DISK WRITE : 0.00 B/s Actual DISK READ: 0.00 B/s | Actual DISK WRITE: 3.77 M/s TID PRIO USER DISK READ DISK WRITE SWAPIN IO> COMMAND 1408 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % getty 38400 tty2 1 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % init  2 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [kthreadd] 3 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % [ksoftirqd/0] 1412 be/4 root 0.00 B/s 0.00 B/s 0.00 % 0.00 % getty 38400 tty6
My guess is that this writing wakes up the hard drive again immediately. The hard drive has a single partition formatted with ext4, and journaling is off.
What could be the cause of this excessive writing? Am I right that this could interfere with standby mode? How should I fix this?
Edit: Regarding NAS, there is currently no software installed (Samba, Apache, ...). In fact it is a fresh install of Debian without anything else. No software accesses the hard drive, at least not that i am aware of.