HDD size
in [Storage]
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From: Dragon on 11 Apr 2006 16:47 I thought I understood HDD size but perhaps not! Have a used 2.5 HDD in USB enclosure. Label says 4.86gb Format as NTFS and it shows as 4.02gb As FAT 32 as 4.01gb Understand (I think) about 1000 versus 1024 as kilo etc. At gb level that gives a factor of 1.074 (1.024 cubed) That gets the 4.02 up to 4.32. Checking the disk under XP shows nothing wrong. Where is the rest? Henry
From: Dave (from the UK) on 11 Apr 2006 17:08 Dragon wrote: > I thought I understood HDD size but perhaps not! > Have a used 2.5 HDD in USB enclosure. > Label says 4.86gb > Format as NTFS and it shows as 4.02gb > As FAT 32 as 4.01gb > Understand (I think) about 1000 versus 1024 as kilo etc. > At gb level that gives a factor of 1.074 (1.024 cubed) > That gets the 4.02 up to 4.32. > Checking the disk under XP shows nothing wrong. > Where is the rest? > > Henry My guess is Windoze will need to use some space to keep track of the files. Each file will have a name - the characters on that name will take up some bytes, but don't detract from the amount of space available. Date / time of modification, creation, access permissions etc all need space. So space has to be found for data structures that keep information about the files. Each file will probably have more than one block on the disk. Exactly what blocks make up the file need to be stored. All this information takes up space, so a file system will have less available than the raw disk. I don't know about Windoze, but on UNIX you can tune the file system to get more space if you know there will be few files by having less inodes. Also on UNIX systems, the amount of space reported free is that available to normal users. The 'root' user has a bit more space. Perhaps windoze does this to. Are you overlooking the swap file? Just ideas. -- Dave K MCSE. MCSE = Minefield Consultant and Solitaire Expert. Please note my email address changes periodically to avoid spam. It is always of the form: month-year(a)domain. Hitting reply will work for a couple of months only. Later set it manually.
From: Rod Speed on 11 Apr 2006 17:10 Dragon <qz39dragon.trapbait(a)ntlworld.com> wrote > I thought I understood HDD size but perhaps not! Certainly not. > Have a used 2.5 HDD in USB enclosure. > Label says 4.86gb > Format as NTFS and it shows as 4.02gb > As FAT 32 as 4.01gb Thats just the different space occupied by the directory structures. > Understand (I think) about 1000 versus 1024 as kilo etc. > At gb level that gives a factor of 1.074 (1.024 cubed) > That gets the 4.02 up to 4.32. > Checking the disk under XP shows nothing wrong. > Where is the rest? Used for the directory structures, fats etc.
From: Dragon on 11 Apr 2006 17:25 "Rod Speed" <rod.speed.aaa(a)gmail.com> wrote in message news:4a2k9hFqt1mhU1(a)individual.net... > Dragon <qz39dragon.trapbait(a)ntlworld.com> wrote > >> I thought I understood HDD size but perhaps not! > > Certainly not. > >> Have a used 2.5 HDD in USB enclosure. >> Label says 4.86gb >> Format as NTFS and it shows as 4.02gb >> As FAT 32 as 4.01gb > > Thats just the different space occupied by the directory structures. > >> Understand (I think) about 1000 versus 1024 as kilo etc. >> At gb level that gives a factor of 1.074 (1.024 cubed) >> That gets the 4.02 up to 4.32. >> Checking the disk under XP shows nothing wrong. >> Where is the rest? > > Used for the directory structures, fats etc. Is that still true when I've put no directories/folders or files on the drive? The arithmetic I did on my main drive seems to come out right without a missing half gig. Also worked OK on a nominal 20gb drive in a USB enclosure. Could some of the drive be 'bad blocks' or whatever and no longer available? It's quite an old drive. DBCA-204860 from 1999 Henry
From: Rod Speed on 11 Apr 2006 18:05
Dragon <qz39dragon.trapbait(a)ntlworld.com> wrote > Rod Speed <rod.speed.aaa(a)gmail.com> wrote >> Dragon <qz39dragon.trapbait(a)ntlworld.com> wrote >>> I thought I understood HDD size but perhaps not! >> Certainly not. >> >>> Have a used 2.5 HDD in USB enclosure. >>> Label says 4.86gb >>> Format as NTFS and it shows as 4.02gb >>> As FAT 32 as 4.01gb >> Thats just the different space occupied by the directory structures. I meant that about just the last two lines above. >>> Understand (I think) about 1000 versus 1024 as kilo etc. >>> At gb level that gives a factor of 1.074 (1.024 cubed) >>> That gets the 4.02 up to 4.32. >>> Checking the disk under XP shows nothing wrong. >>> Where is the rest? >> Used for the directory structures, fats etc. > Is that still true when I've put no directories/folders or files on the > drive? Yes, there is quite a bit of that even with no files or folders added. Most obviously with the FATs which occupys the same space regardless of whether there are any files and folders on the drive. Its more complicated with NTFS but the same thing still applys. > The arithmetic I did on my main drive seems to come out right without a > missing half gig. Yes, but the FATs and other directory structures still need to be there. > Also worked OK on a nominal 20gb drive in a USB enclosure. Not clear if you mean that drive doesnt have half a gig 'missing' or not. > Could some of the drive be 'bad blocks' or whatever and no longer > available? Nope, those should be invisible. > It's quite an old drive. DBCA-204860 from 1999 It shouldnt have half a gig of bads unless its dying. |