Hi > > It would be nice to see smart stats saying, we got this much shock > > before we managed to park the heads.
As far as I can see this is non statement. What shock is needed for the disk data reader to touch the spinning disk. If this shock occurs there is no time to do any disk parking. MTBF is based on the assumption that repeated environmental stresses are below a certain value. If the environmental stress is above a certain value than a phenomena known as cyclic stress fatigue will be of great influence on the failure rate. Please excuse me if I have not quite got the right terms it is over 20 years since I was involved in quality and reliability. There are also other effects that MTBF does not take account of. There are effects that come about due to ageing that can only be determined by running something for the actual length of time concerned. Hard disks fail very quickly if they have to operate in a tank. John Eayrs On Monday 20 July 2009 14:27:09 Stephen Rowles wrote: > James Courtier-Dutton wrote: > > None of the above smart parameters give any indication from the > > accelerometers. So, one has no way of telling if shock was a contributing > > factor to the HD failure. > > It would be nice to see smart stats saying, we got this much shock > > before we managed to park the heads. > > > > Another thing, for the pre-fail smarts like: > > Raw_Read_Error_Rate 16203744 > > Seek_Error_Rate 139114079 > > Hardware_ECC_Recovered 164354431 > > > > What is an acceptable value and what indicates things starting to go > > wrong? My laptop HD has these values at zero!!! > > On my desktop, they keep increasing over time. So, what is an > > acceptable "rate" ? > > > > James > > Unfortunately this is my work desktop machine, I don't think it has an > accelerometer in it... my personal laptop at home would appear to have > this line: > > 191 G-Sense_Error_Rate 0x000a 100 100 000 Old_age > Always - 0 > > Which according to google is something to do with shock-sensitive sensor > on the drive. > > Unfortunately I'm not an expert in analysing the output to tell you what > the numbers mean, I expect there is some software that will do a better > analysis job but I don't know of any off-hand. I've only used it once > before in anger on a drive that was making odd noises and behaving > strangely, one of the numbers was huge, which I looked up and google > suggested it indicated a failing drive, so I backed up the data and > replaced it :) -- Please post to: Hampshire@mailman.lug.org.uk Web Interface: https://mailman.lug.org.uk/mailman/listinfo/hampshire LUG URL: http://www.hantslug.org.uk --------------------------------------------------------------
