Hopefully this is the right forum for this..

I have 4 data hard drives which are set with hdparm to standby after 30 mins, but the problem is that they (all 4 because I have XDG folders on them) wake up each time I run any program with "Places" tab (Dolphin, Gwenview) or browser dialog with places tab; and with Amarok it is similar without going in "My Collection" the hard drives always wake up. I suppose Nepomuk/Strigi will be doing the same. The waking up is pretty annoying because the UI freezes for a moment, the noise level raises up and of course power consumption is increased.

So the conclusion is why don't (or how to enable this) programs check hdd if it's in standby mode and if yes only wake it if user actually wants to work with it.

You may wish to check that the disk space used indicators in Dolphin's status bar and places area are disabled.
I am not aware of any settings in this regard though ( to specifically avoid waking up hard disks )

The main reason why applications probably don't check is because HAL doesn't expose this information to the applications, hence they probably don't even know...

Hmm.. as I mentioned this happens in Gwenview and other apps too (they don't have space indicators) so.. it's reasonable to suppose that disk space indicators might cause wake up but they aren't the root cause..

other thing is that I'm not really aware how exactly HAL or maybe even udev works only thing I can say is that Firefox doesn't wake up my disks even when showing dialog with "Places"

I'm not using any other GTK apps so I can't really tell how they behave but if it would help solve my (and maybe others) problem I can test it

If you can run the affected applications using strace or a similar tool which can report where on these disks are being accessed it would be very helpful.

1. I'm not familiar with strace (I'm just average user) so output from strace is too big to be useful (I can't even copy all that data) if you can provide parameters I should use I can post the output

2. yesterday I upgraded to (K)ubuntu 10.04 and suddenly I can't reproduce the behaviour.. all works like it should (wake ups only after I'm accessing folders/files on standby hdd) or even better (with caching of most used folders/files)
so I guess this version of hdparm is preventing this(?) ..only program that wake ups my drives without accessing them is amarok now

I'll keep my eye out on this and if I'll see something I'll post the findings

*btw it's ironic that finally after posting this promblem (it bugged me 1.5 year) it suddenly works

Good to hear that it is essentially fixed now.

This is probably caused by a combination of kernel disk caches and better behaviour by KDE.

so I've been monitoring this past days and my findings are rather confusing.. like I couldn't reproduce it 2 days ago now the waking up moves from occasional to most of the times when I use application mentioned before. At fist I thought that it might be because I have preload installed but when I removed it nothing changed. Any ideas how can I track what's causing this?

Unfortunately the only utility I am aware of that can track file system operations performed by applications is strace, which I don't know how to interpret myself.