Path: utzoo!news-server.csri.toronto.edu!cs.utexas.edu!uwm.edu!ux1.cso.uiuc.edu!mp.cs.niu.edu!bennett From: bennett@mp.cs.niu.edu (Scott Bennett) Newsgroups: comp.sys.next Subject: Re: Misc questions Message-ID: <1991Mar6.042640.7119@mp.cs.niu.edu> Date: 6 Mar 91 04:26:40 GMT References: Organization: Northern Illinois University Lines: 47 In article rpruess@umaxc.weeg.uiowa.edu (Rex Pruess) writes: >In article aberno@questor.wimsey.bc.ca (Anthony Berno) writes: >> Does anyone else have this problem with missing disk space? If you wouldn't >> mind, please do the above calculation and tell me what you get. I'm curious > >Hmmm. I'm curious now. > >Looking at the mkfs and df output, there is a fair amount of space used >before you even get a chance to save files on the disk. I assume mkfs >takes a good chunk of space for overhead (e.g., superblocks, inode >allocation, and reserved space for efficiency). > >Here's a chopped down version of the mkfs output: > /etc/mkfs -N /dev/rsd0a 357560 22 10 8192 1024 32 10 60 4096 > /dev/rsd0a: 357560 sectors in 1626 cylinders of 10 tracks, 22 sectors > 366.1Mb in 51 cyl groups (32 c/g, 7.21Mb/g, 1728 i/g) > >The mkfs parm 357560 is the number of 1024 byte sectors. This yields >a total space of: > 357,560 * 1024 = 366,141,440 bytes Worse yet, many (if not most) disk drive vendors incorrectly advertise the capacity of their products. For example, in the above case many vendors would advertise the drive as a 366MB drive. This is wrong because 1MB=1024KB=1048576B. So, from this we can calculate in reverse that 366141440B=357560KB=~349.18MB, *not* 366MB. It would be nice if the vendors would stick to straight info, rather than just adding to the confusion. > > [remainder of text deleted --SJB] >-- >Rex Pruess, Weeg Computing Center, Univ of Iowa, Iowa City, IA 52242 >rpruess@umaxc.weeg.uiowa.edu (NeXTmail) (319) 335-5452 Scott Bennett, Comm. ASMELG, CFIAG Systems Programming Northern Illinois University DeKalb, Illinois 60115 ********************************************************************** * Internet: bennett@cs.niu.edu * * BITNET: A01SJB1@NIU * *--------------------------------------------------------------------* * "I, however, place economy among the first and most important * * of republican virtues, and public debt as the greatest of the * * dangers to be feared." --Thomas Jefferson * **********************************************************************