10-16-2016, 04:43 AM
Safest option is to use "Something else" so you can manually direct installation exactly as you want. 1st option (replace) may very well wipe out everything even though the wording doesn't clearly imply that.
Is your large data partition your Home partition, or is it just a separate partition you made for data storage with a different mount point?
If it is your Home partition go ahead and follow video posted by torreydale. Took a quick glance at that video. For demo purposes, he starts by installing an old version of Mint, then describes some backup procedures, and then shows procedure to install new version of Mint and re-use the Home partition without wiping out the data on it. So, you can probably skip to about 1/2 way through where he describes replacing old OS with new one. Basically you set the mount points for Root, Home and Boot (if you have one) partitions, but only format the Root and Boot partitions. Do not format the Home partition -- just set its mount point so it gets used for the new install but not overwritten. (If you don't have a Boot partition ignore that part of video. Boot partitions are not necessary, so don't think that you must create one if you don't already have one. I've never used one myself.)
If your Home folder is actually part of the Root partition and that large data partition is separate and mounted somewhere else, you may want to back-up any config files in Home that you want to re-use. (Eg. Configs for Firefox, Thunderbird, etc.) In that situation you will loose whatever is in Home because it's part of the Root partition which will be overwritten. As for the separate data partition, you can either not deal with it during install and set it up to be mounted afterwards; or you can manually type in whatever mount point you want for it during the install so you don't have to do it later. If you do set the mount point during install, be sure NOT to check the format box for that partition.
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