I've noticed a mysterious variation in the size of IFL image files. For instance, I recently made changes to my Linux installation which reduced by several Mb the hard-drive space it occupies; yet when I took a new image of the installation, the image was several Mb *larger* than the one I had taken before making the changes. I wonder why that could be, please? I used exactly the same IFL options when taking the two images. Moreover, these are fairly small image files, only 200Mb or so from an installation taking up less than 500Mb.
Of course this isn't a problem; it isn't even important. I'd just like to understand what's going on! Many thanks.
Variation in size of IFL image files
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Re: Variation in size of IFL image files
Brian49 wrote:
> I've noticed a mysterious variation in the size of IFL image files. For
> instance, I recently made changes to my Linux installation which reduced by
> several Mb the hard-drive space it occupies; yet when I took a new image of
> the installation, the image was several Mb *larger* than the one I had
> taken before making the changes. I wonder why that could be, please? I used
> exactly the same IFL options when taking the two images. Moreover, these
> are fairly small image files, only 200Mb or so from an installation taking
> up less than 500Mb.
>
> Of course this isn't a problem; it isn't even important. I'd just like to
> understand what's going on! Many thanks.
It doesn't sound like anything to worry about if it's just a few MiB you're talking about - but how did you measure the decrease in space used? If you look at what IFL shows in it's "F1 Details" screen (CUI), or "Information/Details" screen (GUI) for that partition, it will show something like (as an example):
2500 MiB Used
3100 MiB Free
The size of the image file will roughly correlate with the MiB Used number, but that will vary also depending on how compressable the files are (text files vs binary files, etc.).
Another thing that comes to mind that some aren't aware of is that when you do package updates in Linux, most distros will keep the package files it downloads for the update in a cache folder (/var/cache/apt/archives for Debian) even after installing the packages. Those files will continue to accumulate during each update until you delete them with a command like 'apt-get clean' (Debian). That could explain why your used space could increase after you deleted a few programs (packges) thinking it would decrease the space used, but then ran a system update, which downloaded more package files to increase the space used again.
> I've noticed a mysterious variation in the size of IFL image files. For
> instance, I recently made changes to my Linux installation which reduced by
> several Mb the hard-drive space it occupies; yet when I took a new image of
> the installation, the image was several Mb *larger* than the one I had
> taken before making the changes. I wonder why that could be, please? I used
> exactly the same IFL options when taking the two images. Moreover, these
> are fairly small image files, only 200Mb or so from an installation taking
> up less than 500Mb.
>
> Of course this isn't a problem; it isn't even important. I'd just like to
> understand what's going on! Many thanks.
It doesn't sound like anything to worry about if it's just a few MiB you're talking about - but how did you measure the decrease in space used? If you look at what IFL shows in it's "F1 Details" screen (CUI), or "Information/Details" screen (GUI) for that partition, it will show something like (as an example):
2500 MiB Used
3100 MiB Free
The size of the image file will roughly correlate with the MiB Used number, but that will vary also depending on how compressable the files are (text files vs binary files, etc.).
Another thing that comes to mind that some aren't aware of is that when you do package updates in Linux, most distros will keep the package files it downloads for the update in a cache folder (/var/cache/apt/archives for Debian) even after installing the packages. Those files will continue to accumulate during each update until you delete them with a command like 'apt-get clean' (Debian). That could explain why your used space could increase after you deleted a few programs (packges) thinking it would decrease the space used, but then ran a system update, which downloaded more package files to increase the space used again.
Re: Variation in size of IFL image files
Thanks for responding.
I use an application called Conky to monitor drive-space usage from within my Linux installation; it's usually pretty accurate (as far as I can tell).
I empty all caches routinely, and especially before taking a backup image. It's on that basis that I am comparing the "before" and "after" values.
So my guess is that the apparent discrepancy has to do with the point you raise about how compressible the files are. Thanks again.
I use an application called Conky to monitor drive-space usage from within my Linux installation; it's usually pretty accurate (as far as I can tell).
I empty all caches routinely, and especially before taking a backup image. It's on that basis that I am comparing the "before" and "after" values.
So my guess is that the apparent discrepancy has to do with the point you raise about how compressible the files are. Thanks again.