Hi, I just wanted to follow up on my original question and to thank all those who offered help.
It appears that the clicking I heard was due to my disk(s) being put to sleep, as John Stalberg suggested. This morning I unchecked the "put the hard disk(s) to sleep when possible" box in the Energy Saver preference panel. I did not notice the clicking sound for a long time, but after about 6 hours I heard it again. I looked at the Energy Saver panel and the box was checked again. Just before that, I noticed some sysadmin process running, which I assume was re-instating the mandated energy saving settings (including a check in the box for putting disks to sleep). So, unless this is a gigantic coincidence, it appears that the sounds I heard were the head(s) on my hard drive(s) being parked after the default time period (10 minutes) of inactivity. Thanks, Gregg On 20 Jul 2011, at 10:16 AM, Dinse, Gregg (NIH/NIEHS) [E] wrote: > Hi John, > > Thank you for the idea that the noise may be related to the disk(s) spinning > down at the default time (10 minutes). This may be exactly what is causing > the sounds that I hear. I will check into it. > > Until recently, I believe that the check box in the Energy Saver panel for > "put the hard disk(s) to sleep when possible" was NOT checked. About a week > or two ago, which is about when I started hearing these noises, the sysadmin > folks made some energy saving changes to all systems. I forgot about this, > but now I see that the box is checked, so that may explain the noises that I > hear. To test this, I will uncheck the box for a few days and see if I still > hear anything. > > By the way, for energy saving reasons, I can see why it might be a good idea > to put the disks to sleep. Overall, is this good or bad for the health of > the disks? Does frequent sleeping and waking put added strain on the disks, > so that it is better to let them always run, or is there really no > significant disadvantage to putting the disks to sleep? > > Thanks, > > Gregg > > On 19 Jul 2011, at 11:27 PM, John Stalberg wrote: > >> On 20 jul 2011, at 02:43, Macs R We <[email protected]> wrote: >> >>> On Jul 19, 2011, at 3:50 PM, Dinse, Gregg (NIH/NIEHS) [E] wrote: >>> >>>> Hi, >>>> >>>> Thanks for the information. I guess one of my hard drives is probably >>>> bad, or going bad. >> >> The time you mention, 10 minutes, match the default spin down time. You say >> the clicks comes when the machine doesn't do anything (user generated >> stuff). If the machine doesn't do anything for 10 minutes, the system hard >> drive most often spin down. This is dependent on the setting in System >> Preferences ~> Energy Saver ~> Put hard disk to sleep when possible. 10 >> minutes is the default time until spin down. Some disk's are quiet and >> others are audible. It might be a noice that would be within what the >> manufacturer have specified if speced at all? I think newer disk drives are >> less noisy than older ones. >> >> Since it is difficult to take a description of the sound instead of >> experience it ir on location, I can't say if the sound is beyond reasonable >> or not? >> >> But this is probably a lousy point in time to try to save a buck or two. >> Hdd's doesn't cost much. I recomend you to consider using RAID0 mirrors on >> the internal drives. It would theoretically allow you to keep the >> questionable disk drive up and running, without any reason to be overly >> nervous for a disk drive failure. >> >> If you can afford it, and don't need all these drives for other purposes, >> you could buy 4 drives for RAID10 (both speed boost and redundancy. >> >> You could also buy 3 disk drives and take 2 for a mirrored pair and let the >> third be a spare. Or just 2 and no spare. Or just one and perhaps find >> yourself in this nervous situation again if that single drive missbehaves as >> this does? >> >> If you can get informed about when disk spin down is executed you could >> listen and see if the two match? >> >> // John Stalberg _______________________________________________ MacOSX-talk mailing list [email protected] http://www.omnigroup.com/mailman/listinfo/macosx-talk
