Hi,
I'm having a grief with Seagate FreeAgent Pro drive connected to CentOS 4 box via USB. The problem is that drive is factory configured to take a nap (spin down) after some 15-20 minutes of inactivity, and there doesn't seem to be a way to disable it. Since it's USB connected, hdparm can't be used on it. Getting the drive out of the case is not an option either, since it would probably void the warranty (and there's still 4.5 years of it left). There's eSATA connector on the drive too, but I don't have anything on the PC side to connect it to. There's also FireWire connector, but somebody at big red company decided users don't need FireWire (and I'd probably have same problem if the drive was connected via FireWire too).
The problem with the drive spinning down is that Linux doesn't really like when that happens. It reports that drive is not responding, spits bunch of I/O errors for the device in the logs, and refuses any operation on the file system(s) that are on that drive. In contrast, Windows, Mac OS X and some other boxes I tried to connect the drive to have no problem with it (drive simply spins up when accessed). There was a patch in relatively recent Linux kernels that adds allow_restart option (accessible from /sys), which apparently should solve the problem for Linux (described here: http://www.nslu2-linux.org/wiki/FAQ/DealWithAutoSpinDownOnSeagateFreeAgent). When allow_restart is set to 1 (default is 0), Linux will do what all other operating systems do by default, spin up the drive on access. However, kernel included with CentOS 4 is not recent enough, and doesn't have that option.
Anyhow, my question is (after probably describing things a bit too much), does the kernel included with CentOS 5 supports allow_restart? Could somebody (anybody) running CentOS 5 could check if either of these paths exists on his/her system:
/sys/block/sda/device/allow_restart
or
/sys/class/scsi_disk/0:0:0:0/allow_restart
If they do exist, I'll be probably upgrading my box to CentOS 5 pronto... If they don't, well, might still upgrade but it won't solve the problem I'm having...
Thanks, Alex