** Description changed: - It is claimed that some systems are seeing an unusually high number of - load/unload cycles on their hard disks, as evidenced by smartctl. + It is confirmed that some systems are seeing an unusually high number of + load/unload cycles on their hard disks, as evidenced by smartctl. It + was originally surmised that this was related to laptop-mode being + enabled, but this affects systems *regardless* of whether or not laptop- + mode has been enabled. In fact, aggressive APM is not a bad idea while + a system is not on AC, as that system is much more likely to encounter a + physical impact. But unfortunately, the heads never stay parked, due to + very frequent disk activity. - If laptop mode is enabled (which is NOT the default), then when - switching to battery power, /etc/acpi/power.sh issues the command hdparm - -B 1 to set IDE and SCSI disks to power saving mode, so enabling laptop - mode may be related to this observation. + This problem has been confirmed in Ubuntu as well as in other + distributions. - For example, my new thinkpad has already done well over 7000 load cycles - -- in only 100 hours. That's at least one unloading per minute. Googling - for "load unload cycles notebook OR laptop" shows that most laptop - drives handle up to 600,000 such cycles. + Symptoms of this bug are: + * frequent HD clicks -- more than one per 3 minutes while idle, louder than the typical access sounds. Often more than twice per minute. + * Rapidly Increasing Load_Cycle_Count as displayed in the final number in "sudo smartctl -a /dev/hda | grep Load_Cycle_Count" (where /dev/hda is replaced with your own hard disk device) + * Early hard disk failure -- some disks are cut down to less than a year of actual uptime. + + The problem seems to be caused by: + * Hardware defaults to aggressive power management, causing heads to park. + * Disk is touched often, causing heads to unpark. + * Most laptop drives handle up to 600,000 such cycles. + + Reasonable Limits / Criteria for a fix: + * There should be fewer than ~15 load cycles per hour, except during heavy usage while on battery. + * This provides a life expectancy of over four years, which is reasonable for a hard disk. + + Temporary Workaround: + * Search for "hdparm -B 254" below. + + Some hardware with this issue: + WD1200VE -- http://www.wdc.com/en/library/portable/2879-001121.pdf -- This aggressive parking is a feature of this disk, but that feature relies on behaviour that allows for significant amounts of (truly) idle time without the disk being touched. Notice the "Load/unload cycles" of 600,000. + + Example Load_Cycle_Counts: + * Thinkpad Z60m/Hitachi HTS541080G9SA00 with well over 7000 load cycles in only 100 hours. That's >70 per hour. + * Gateway MT6451/Western Digital WD1200VE with 164762 load cycles in 3747 hours (156 days) of uptime. That's ~43 per hour -- except that the system was patched during the initial third of its life, which puts it at ~63/hour since Gutsy was installed (and wasn't patched, as I had done with feisty). Please see for yourself how often your drive is load cycling: smartctl -d ata -a /dev/sda (This command is for an SATA drive; you'll need to install the smartmontools package first.) + You can get the average per minute by the following division: + Load_Cycle_Count / Power_On_Hours + See also http://paul.luon.net/journal/hacking/BrokenHDDs.html for a rather dramatic account of the effects the current default values may have. - - Just in case the load/unload timeout depends on the specific laptop or disk model, here are my system specifications: - ThinkPad Z60m & Hitachi HTS541080G9SA00 disk (80GB)
** Tags added: click count cycle hd load noise -- High frequency of load/unload cycles on some hard disks may shorten lifetime https://bugs.launchpad.net/bugs/59695 You received this bug notification because you are a member of Ubuntu Bugs, which is the bug contact for Ubuntu. -- ubuntu-bugs mailing list ubuntu-bugs@lists.ubuntu.com https://lists.ubuntu.com/mailman/listinfo/ubuntu-bugs
