You will need to freeze it since canning it makes a product that is too dense. It will not stay into chunks in the jars. Canning it would lead to a possible risk of botulism due to the density of it.
Spaghetti squash freezes very well, and is handled a
bit differently from other winter squashes. Wash, slit in
half lengthwise and scoop out the seeds. Place squash, cut
side up, in shallow baking pans and bake at 375 degrees
Fahrenheit for 30 minutes. Remove from the oven and cool
until the squash can be easily handled. Pull a fork
lengthwise through the flesh to separate it into long
stands. Pack into freezer bags, seal, label and freeze.
To reheat frozen squash, partially thaw, then steam,
stirring occasionally until tender but still firm, eight
to fifteen minutes.