Fr@nky and others who may be lost:
Am I affected by this issue????
The answer is yes if you have a latop hard disk drive (hdd), or possibly other hdds with aggressive energy saving settings (like the Western Digital green products), and you have a default (X)Ubuntu installation. (I assume that this is true for Kubuntu as well, but I don't know for sure.)
Most desktop hdd's are probably not affected. However, a laptop hdd in a desktop would most likely be affected.
My understanding is that rapidly increasing Load_Cycle_Count does not depend on laptop-mode being active. I believe laptop-mode is disabled by default (not sure about newest version.) The (separate) issue with laptop-mode is that the battery setting for harddrive power management is VERY aggressive.
To know for sure if this issue affects you, follow these instructions to determine your S.M.A.R.T. readout.
http://ubuntuforums.org/showpost.php...0&postcount=26
Note that you want to look at the rate the Load_Cycle_Count is increasing over time. You should read on if you see a count increase of more than 1 per minute.
The Issue:
The issue is caused by a complication of behaviors, all of which contribute. In my opinion, its not technically a bug, because all of these behaviors separately are intentional. However, with laptop hard drives, these behaviors combine to form a highly undesirable behavior to many (but not all!) These seem to be the behaviors involved:
1. Laptop hard drive BIOS and/or laptop BIOS sets aggressive hdd settings to protect the physical drive from damage due to impact (dropping or bumping the laptop), as well as to save battery power. These include parking/unparking the hdd heads. Jarring the hdd hard enough when the heads are over the platters may cause the heads to actually hit the platters, damaging them and causing data loss. Keeping the heads in a parked state prevents this. Therefore, laptop hdd's often park the heads after a short period of disk inactivity. Also included is disk spindown, which saves battery power.
2. (X) Ubuntu (and other distros) does not override hardware settings by default. Therefore, the hdd manufacturer settings are not modified normally. This means that the manufacturer settings apply whether or not the laptop is plugged in, or on ac power, or in standby. The manufacturer settings apply for laptops, desktops, servers, anything running a default Ubuntu install. Enabling laptop-mode or installing laptop-mode-tools may modify these behaviors, but that would require user intervention.
3. Linux based distros constantly access the hdd. Some, but surely not all, processes include file system journaling (once every 5 sec. in ext3), access time logging, file indexing, acpid output, thunderbird, etc. In many cases these are desired behaviors. File system journaling helps protect the integrity of your file system, and thus, your data. Indexing has to do with file searching. Beagle, for instance, is a real-time indexer, which allows constant hdd access. Thunderbird may be accessing the hdd to check for new messages.
The problem is that these behaviors together (really, 1 and 3) are causing the issue. Your hdd parks the heads after a hdd access to protect the disk. Very soon thereafter, the heads unpark to access the disk (eg. ext3 journals every 5 sec). So basically its a back-and-forth battle for control of the heads between the hdd/laptop BIOS and the OS. Park to protect, unpark to access, park to protect, unpark to access. This issue is NOT limited to Ubuntu. Similar behavior has been observed with other linux based distros, and Windows OS's! It does appear that the rate of Load_Cycle_Count increase on affected systems can be higher in linux based OS's (one comparison from ifixit: ubuntu = 420/hr, vista = 26/hr. Note that the rate increase under linux based systems does vary - best to check your own and decide if its a problem to you.)
The problem with "fixing this bug" in Ubuntu is that decreasing the high rate of Load_Cycle_Count increase may require sacrificing desired functionality. One may want to sacrifice drive life to have solid file system integrity. Or, somebody may want aggressive head parking because that person is rough with their laptop. And, somebody may want to preserve drive life by preventing head loading unloading. In a more configurable distro (like Gentoo), its up to the user to determine what he/she wants and therefore, how to setup the OS. However, Ubuntu is more of a "works out of the box" distro. The tough thing for Ubuntu is that it must "work out of the box" for many different systems. IMHO, maybe some usage questions during install could help customize the install for the particular computer. Something like "User, are you installing Ubuntu on a laptop?" If yes, allow aggressive settings on battery mode, but not on ac mode, or something like that.
The Ugly Fix
If you wish to prevent aggressive hdd settings, and the resulting rapid increase in Load_Cycle_Count that may indicate premature hdd wear and tear, follow the directions here:
http://ubuntuforums.org/showpost.php...0&postcount=26
Anyone can feel free to correct this and repost it or wiki it or something, so that people can know whats going on without wading through 38 pages of posts. (Although correcting any mistakes would be really important, then.) Clearly, this post has been a collection of information in the previous 38 pages, as well as from the internet, and many others. Ubuntu_demon is really to be commended for gathering information and fixes, and updating the bugtracking on this issue.