Greg Cormier wrote: > Is it possible to sleep hard drives in an array? yes - to be clear you sleep the drives though, not the array. > Can I sleep the drives in my RAID5 array while it's not being used? > It's an XFS partition. XFS is bad at this IIRC. Certainly noatime is important to prevent cache accesses from updating the fs. > > But I'm fairly sure they are not spinning down :( Is there some > activity mdadm is doing in the background? from Documentation/laptops/laptop-mode.txt: If you want to find out which process caused the disk to spin up, you can gather information by setting the flag /proc/sys/vm/block_dump. When this flag is set, Linux reports all disk read and write operations that take place, and all block dirtyings done to files. This makes it possible to debug why a disk needs to spin up, and to increase battery life even more. The output of block_dump is written to the kernel output, and it can be retrieved using "dmesg". When you use block_dump and your kernel logging level also includes kernel debugging messages, you probably want to turn off klogd, otherwise the output of block_dump will be logged, causing disk activity that is not normally there. also google found http://www.nslu2-linux.org/wiki/FAQ/HowtoIdentifyWhichProcessesAccessDisk Before going too far, make sure the array is up but not mounted and ensure that the drives will actually spin down. David -- To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
