I'm answering below in capital letters:
In a way, Acronis does in fact say how much space it needs...
In particular, the area where you select compression... It specifically states it's estimated image size for each compression level... The estimates it makes on my machine are actually too high... Acronis claimed 28GB, and the finished image was only 20GB...
YES, I KNOW, I GAVE YOU THE NUMBERS ACRONIS SAID THE IMAGE WILL BE -- ABOUT 83 GB AT NORMAL COMPRESSION, AND ABOUT 72 GB AT MAXIMUM COMPRESSION - THIS ON SPACE THAT HAS 99+ GB EMPTY
Are you selecting "Sector by Sector" by chance ?... Don't...
NO, I MEANT TO MENTION THAT, I USED THE OTHER WAY, FULL OR WHATEVER ITS CALLED, SECTOR BY SECTOR IS SLOWER AND IS NOT HOW I DID THE 8.1 IMAGE. WHATEVER ITS CALLED, I DID NOT DO SECTOR BY SECTOR.
I did some checking on image size differences between Used Space, Windows Image, and Acronis Image...
Here's an example... you can calculate the percentages for your machine if you wish, but I think my numbers make things obvious...
I have a 128GB SSD with 53GB of Used Space as determined by the Windows Image feature and C:\ Properties...
Windows claims it will need UP TO 54GB to create an Image...
The actual image is 33GB...
This is because I have two System Files on C:\ that are empty when doing a restart, and are used as needed by Windows when running... PageFile and HiberFil...
On my machine they always take up 12.5GB each... even though they may be empty...
These files were basically empty when the image was made, so it ended up being 20GB smaller than the estimate...
OK, SO YOU;RE SAYING IT MIGHT BE WROTH TRYING TO DO THE IMAGE FROM THE OS BECAUSE EIT MIGHT BE WELL SMALLER THAN THE 126 GB IT SAYS IT MIGHT NEED -- IT MGHT NEED AS MUCH AS THAT, BUT MIGHT NEED SUBSTANTIALLY LESS. THAT IS THE SIZE OF ALL THE FILES,
SO IT WON'T NEED MORE THAN THAT. BAD COMMUNICATION BY THEM. OK, I CAN GIVE IT A TEST RUN. IN FACT, MAYBE I'LL GO START THAT NOW. WELL, ANOTHER THING I DO'T LIEK ABOTU THAT IS IT WILL IMAGE EOINLY THE THREE PARTITIONS, EFI, PRIMARY, AND THE 15 GB RECOVERY.
THE OTHER THREE ARE LEFT BEHIND, AND I WOULD LIKE TO GET THEM. THE OS DOES NOT PROVIDE OPTIONS IN SETTINGS TO PICK WHICH PARTITIONS NOR COMPRESSION LEVEL OR ANYTHING. I DO WANT A BACKUP THAT INCLUDES ALL THE GATEWAY STUFF. IT ALSO DOESN'T LET ME PUT
IT ON THE DRIVE WHERE I WANT IT, DOESN'T EVEN TELL ME WHERE IT IS PUTTING IT. HMM, DOESN'T EVEN SAY WHETHER I WILL BE ABLE TO ADD TO IT LATER ORNOT -- NO SETTING FOR THAT. MAYBE I COULD ADD THE OTHER PARTITIONS WIHT ACRONIS -- BUT THAT IS MIXING APPLICATIONS
FOR A SINGLE IMAGE?
EDIT: I JUST RAN WHILE WRITING THESE ANSWERS. THE OS STOPPED IT AND SAID IT NEEDED MORE SPACE, NO CLUE HOW MUCH SPACE IT WANTS OR THE ACTUAL SIZE OF THE IMAGE IT WAS GOING TO MAKE.
Then there is the Acronis Image that was made with all default settings... I never touched anything concerning Options... It is 20GB with Normal Compression by Default.
Then I did a Acronis Image with Maximum Compression... It is 18.8GB....
This didn't accomplish much...
The Acronis Images are compressed, but the majority of the size reduction is the 25GB from the empty system folders... The Image would be 28GB with no compression at all... Then 18.8GB with Maximum Compression.. 67%...
If you take your 124GB and subtract the same 25GB... although your's will be a different number... maybe even larger... You end up with about 99GB which should compress to around 66GB... Then add in your other partitions...
RE: External drive... I didn't mention deleting everything and expanding #3 in both directions because of the Hidden 128MB partition...
I don't think there is anything wrong with the #3 partition that wouldn't be corrected by deleting #4 and #5... And I mean DELETE... not just slide the bar over...
OK, I'M NOT SURE THERE IS ANYTHING WRONG WITH ANY OF THEM. HOWEVER, IF THERE IS, ALL THAT HAS BEEN INVOLVED SO FAR IS #3, AND BY THE END OF 4, IT SAID THE IMAGE NEEDED MORE SPACE. THAT SUGGESTS THAT PROBLEM PARTITION IS #3, SINCE THE SPACE ISSUE AROSE
BEFORE ACRONIS EVER DEALT WITH #5 -- AND THUS, THERE APPEARS TO BE AN ISSUE REGARDLESS OF #5. I WILL ALSO SAY, I DON'T SEE WHY #4 WOULD BE AN ISSUE, ALTHOUGH IT MIGHT BE CONSIDERED TO BE UNNECESSARY. BUT IT IS SO SMALL, I'D RATHER KEEP IT WITH ANY GATEWAY
STUFF THAT MIGHT BE ON IT. AND OF THE THREE PARTITIONS THE OS THINKS SHOUD BE TAKEN, IT TAKES #5, SO SEEMS TO THINK THAT SHOULD BE KEPT.
WELL, PERHAPS WE NOW ARE TALKING OF JUST RETAINING THE PRIMARY PARTITION AND EXPANDING IT, AND YOU THINK EXPANDING IT INTO #2 IS A PROBLEM? AT THIS POINT, THE DISK IS BEING LOOKED AT AS MERE STORAGE, NOT BOOTABLE. WE ARE TALKING OF CLEARING OUT ALL THE
MIGRATED FILES FROM THE PRIMARY PARTITION AND EXPANDING IT TO THE SIZE OF THE DISK. I DON'T SEE WHY #2 WOULD BE AN ISSUE FOR THAT. AT ANY RATE, ACRONIS WILL ALLOW ME TO LAP OVER IT AND TAKEN #1 INTO #3, LEAVING #2. #2 IS ONLY 130 MB OR SO, NOT IMPORTANT
FOR SPACE JUST AN IRRITANT TO HAVE AROUND UNNECESSARILY. AND WE ALREADY KNOW TWO PARTITIONS ON THE EXTERNAL IDE BRINGS CERTAIN PROBLEMS OF ACCESS ITSELF -- I CAN'T MAKE AN IMAGE TO A SECOND PARTITION, THERE ARE ISSUES ABOUT A SECOND PARTITION.
BTW... Where are you getting the idea you have all of this available space on #3....
C:\ on the Internal is 124GB used (approx.)...
Half of your 268GB on the #3 is gone right there... 268-124 (approx.)
You said the Win 8.1 image was something like 88GB...
That leaves 56GB... How do you expect to get 75GB on there...
Even if you were successful in obtaining another 15GB from #5, it is still not enough...
TO CLARIFY FOR YOU, FIRST, THE AMOUNT OF SPACE FILLED ON THE PRIMARY PARTITION INCLUDES THE WIN 8.1 IMAGE ON IT. SO, THAT ABOUT 88 GB IS ALREADY INCLUDED, IS NOT SOMETHING TO SUBTRACT AS YOU DID.
SECOND, NOT SURE WHERE THE 268 GB NUMBER CAME FROM, I MIGHT HAVE GIVEN IT. BUT IN LOOKING NOW, THE OS SAYS THAT PARTITION IS 280.38 GB, WITH 99.5 GB EMPTY, 180 GB USED.(THE FULL DISK IS 297.97 GB.)
SO, YOU MISCALCULATED BY SUBTRACTING THE SIZE OF THE WIN 8.1 IMAGE, AND PERHAPS I GAVE A WRONG, LOW NUMBER PREVIOUSLY FOR THE SIZE OF THE PARTITION, MUST HAVE BEEN FOR SOMETHING ELSE.
AGAIN:
PARTITION 1 = 637 MB
#2 =- 300 MB
#3 = 280.38 GB
#4 = 886 MB
#5 = 15.80 GB
AND THE INVISIBLE PARTITION, WHICH IF I RECALL IS SOMETHING LIEK 128 MB OR 150 MB.
If you were to delete #4 and #5 it might just make it... that would be approximately 90GB of useable space without losing any of your migrated #1, #2, or #3... which are by far the most important...
WELL, YOUR COMMENT IS FROM YOIUR ARITHMETIC ABOVE, AND I ALREADY EXPLAINED THE MISTAKE THERE. WE HAVE NO IDEA HOW MUCH SPACE IT WANTS. EVERYTHING I DO COULD MAKE IT SO IT JUST MAKES IT. IT ALREADY MAKES IT, AT MAXIMUM COMPRESSION IT IS ONLY 72 GB,
TO PUT ON 99.5 GB OF SPACE! ANYTHING SUBTRACTED MIGHT MAKE IT -- UNELSS WE ACTUALLY KNEW HOW MUCH SPACE IT WANTED.