Path: utzoo!utgpu!news-server.csri.toronto.edu!bonnie.concordia.ca!thunder.mcrcim.mcgill.edu!snorkelwacker.mit.edu!spool.mu.edu!samsung!uakari.primate.wisc.edu!caen!news.cs.indiana.edu!ux1.cso.uiuc.edu!news.iastate.edu!kickapoo.cs.iastate.edu!hamilton From: hamilton@kickapoo.cs.iastate.edu (Jon Hamilton) Newsgroups: comp.sys.mac.hardware Subject: Re: Leaving the Mac on Message-ID: Date: 25 Feb 91 22:05:35 GMT References: <9262.27c24f4a@cc.newcastle.edu.au> <39523@cup.portal.com> Sender: news@news.iastate.edu (USENET News System) Organization: Iowa State University, Ames IA Lines: 34 yee@osf.org (Michael K. Yee) writes: >In article hamilton@kickapoo.cs.iastate.edu (Jon Hamilton) writes: >> John_Richard_Bruni@cup.portal.com writes: > I like to know how MTBF (mean time between failure) is INCREASED by > leaving a hard drive on? Isn't MTBF expressed in hours? So it > should follow that the less time you have the drive on, the longer > it should last, right? What am I missing here? Is there an implied > reduction in MTBF each time I cycle power on a drive (i.e. minus NN% > MTBF per power cycle)? Hard drives, like most computer equipment, undergo more stress when powering on and warming up than if left running. > BTW: Why would a UNIX filesystems automagically become less > fragmented if you leave the machine idling? No file access happens > when the system is "idle". Does A/UX automatically do hard disk > optimization when the system is idle? most unixes (at least most with ufs) defragment the disk when there's little or no file access going on. Some more often than others, but it is a common feature. > =Mike >-- >= Michael K. Yee -- yee@osf.org or uunet!osf.org!yee -- >= OSF/Motif Development >= "I can't give you brains, but I can give you a diploma." -- The Wizard of OZ -- % Internet : hamilton@kickapoo.cs.iastate.edu | Insert cute and/or % % America Online : JonHam | deeply meaningful % % Elsewhere : ThatGeek@his.little.corner | musical quote here %