[cc'ing Henrique.] Hello, Dark Sylinc wrote: > 1) Like Scott James Remnant, Ubuntu's Development > Manager > (http://www.mail-archive.com/linux-ide@xxxxxxxxxxxxxxx/msg06595.html) > said, in Debian (actually he referred to Ubuntu, but > looking at the code they make the same thing) shutdown > iterates through all /dev/hd* files and shuts them > down. So, if I'm right, sda (the node file for my > friend's PC) is leaved untouch. Why is the warning > appearing then? It is supposed that SATA drives not > using the /dev/hd* convention shouldn't be stopped by > shutdown. Don't have any debian around but apparently it's issuing spin down for /dev/sdX's too. > 2) The kernel Flushes cache and puts in stand-by-now > since 2.6.22 This can cause (if it was already > stopped) the disk to spin up and then down. So.... > anyway the disk should spun down propperly before > power down, it might be done twice, but none of them > would be an emergency shut down. I think I'm missing > something... or otherwise there is no problem at all Well, double spin-down doesn't sound too good and as introducing double spin down would be a kernel regression kernel doesn't issue spin-down if it's already spun down. This is usually okay but some rare drives spin up on FLUSH_CACHE even if the cache is empty which leads to emergency spin down. The warning message is for such cases. > 3) What's the proposed solution after all??? Shutdown > should flush cache AND stop the SATA? or shutdown > shouldn't do anything? > You seem to be in favor of "not doing anything" but > I'm also concerned that Kernel's prior to 2.6.22 would > be negative affected by this solution. Shutdown doesn't need to do anything for later kernels. For older ones, it should continue to issue FLUSH_CACHE and STANDBYNOW1. The presence of manage_start_stop sysfs node can be used to tell which action to take. > 4) What everyone in forums is asking... are they SATA > drives being forced from long time ago, and they have > just found out by using the new kernel? That remains > unclear. I don't really get the question here. Can you please elaborate? > 5) At least on my friend's SATA, the "clack" sounds > like 2 or 3 seconds before power downs, but it sounds > slightly (and really slightly) different to the > Window's shutdown "clack". Does this means that his > drive is safe? Or is it possible for software to power > down just the HDD without stopping the heads??? Sure way to tell is to look at emergency unload count int the output of 'smartctl -a'. Basically, it should identical to 'hdparm -y'. > 5b)I've compiled the kernel without the "Asynchronous > SCSI scanning" flag (SCSI_SCAN_ASYNC). Does it have > something to do that the kernel seems to be waiting > for the SCSI to stop before powering down? Nope. > 6) If I'm not mistaken, in hdddown.c (debian's > sysvinit code > http://packages.debian.org/etch/sysvinit) in line 67 > we should change > static int do_standby_idedisk(char *device) > { > #ifndef WIN_STANDBYNOW1 > #define WIN_STANDBYNOW1 0xE0 > #endif > #ifndef WIN_STANDBYNOW2 > #define WIN_STANDBYNOW2 0x94 > #endif > unsigned char args1[4] = {WIN_STANDBYNOW1,0,0,0}; > unsigned char args2[4] = {WIN_STANDBYNOW2,0,0,0}; > int fd; > > if ((fd = open(device, O_RDWR)) < 0) > return -1; > > if (ioctl(fd, HDIO_DRIVE_CMD, &args1) && > ioctl(fd, HDIO_DRIVE_CMD, &args2)) > return -1; > > return 0; > } > > By: > > static int do_standby_idedisk(char *device) > { > #ifndef WIN_STANDBYNOW1 > #define WIN_STANDBYNOW1 0xE0 > #endif > #ifndef WIN_STANDBYNOW2 > #define WIN_STANDBYNOW2 0x94 > #endif > #ifndef WIN_FLUSHCACHE > #define WIN_FLUSHCACHE 0xE7 > #endif > unsigned char args0[4] = {WIN_FLUSHCACHE,0,0,0}; > unsigned char args1[4] = {WIN_STANDBYNOW1,0,0,0}; > unsigned char args2[4] = {WIN_STANDBYNOW2,0,0,0}; > int fd; > > if ((fd = open(device, O_RDWR)) < 0) > return -1; > > if (ioctl(fd, HDIO_DRIVE_CMD, &args0) && > ioctl(fd, HDIO_DRIVE_CMD, &args1) && > ioctl(fd, HDIO_DRIVE_CMD, &args2)) > return -1; > > return 0; > } Opcode 0x94 is retired now and it's probably not too good a idea to issue it to modern disks. 0xE0 should be good enough and yes you definitely need to issue FLUSH before spinning down the disk. The code needs to be a tad bit more complex. It needs to check manage_start_stop presence and skip any action if it's there. > PS: I'm not a distro mantainer. But I'm concerned > about my friend's SATA, and if we can get to a > solution, I would be glad to report the patch to the > Debian Community ISTR this was resolved somehow and somebody was about to write how to deal with this for debian. Henrique, do you recall anything? Did I drop the ball again? Thanks. -- tejun - To unsubscribe from this list: send the line "unsubscribe linux-ide" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
