OESF Portables Forum

General Forums => General Discussion => Topic started by: suruaZ on January 21, 2005, 12:12:39 pm

Title: Ext2 On Microdrive
Post by: suruaZ on January 21, 2005, 12:12:39 pm

Hi All,

I have tried microdrive with vfat fs and found that it spins only if some i/o access was ordered.
What about ext2 (ext3) on microdrive - does it spins continually due to the journal updates?

Thanks in advance,
suruaZ

Title: Ext2 On Microdrive
Post by: kopsis on January 21, 2005, 03:52:18 pm

ext2 has no journal. On ext3, journal updates are only associated with write operations (which spin the disk up anyway).

The real secret is to make sure you mount the filesystem with the -noatime option. If you don't, then *every* access (read) will result in a write to the directory (to update its access time) and keep the disk spinning more than necessary.

Title: Ext2 On Microdrive
Post by: suruaZ on January 22, 2005, 01:04:36 am

Thanks kopsis,

Now I wonder why I don't able to suspend HD on my laptop after 10 min of idle (with hdparm) as it constanly (every 20-40 sec) accessed from unknown to me reason. As was explained to me this is due to the journal updates (I have ext2).
Well, I need to read more about this  

suruaZ

Title: Ext2 On Microdrive
Post by: kopsis on January 22, 2005, 07:40:44 am

The laptop spim down problem is not due to journaling. It has to do with the IDE interface signaling the kernel when the drive spins down and then the action the kernel takes in response ends up spinning the drive back up.

The microdrive is on the CF interface (and looks like a CF memory card). It doesn't notify anyone that it's spinning down. Its powersaving behavior is completely transparent to the system.