I run a home server with Linux (ubuntu). Data (not the os, not swap, not /home) is stored on a large software RAID5 array.
The server is on 24/7, but to reduce noise I would like the raid drives to spin down automatically after about 10 minutes when they are not accessed.
I've set this with "hdparm -S" for the drives in question, but it will only work if I also set the power management via "hdparm -B" to a value below 128 (default is 254).
Since documentation is pretty slim on the topic: what value would you recommend for a reasonable compromise to achieve a quiet environment, but not increase the strain on the drives extraordinarily?
I can hear the spindle motor, but I don't think it will get any quieter if the heads are parked after each access...
The machine uses 3 WD20NPVT drives (Western Digital 2.5"). I know these are not designed for always-on servers. I can live with that.
I do not really care about power consumption. Performance is also not an issue, this machine streams mp3 files to a maximum of 2 clients for a few hours a day. If it takes 90 seconds for the drives to spin up before the music starts that's fine...