[gdal-dev] Disk space problems when creating in-mem VRT
I'm trying to warp a pretty big raster (120601 x 162961) into a reprojected VRT. I can do that just fine when writing the VRT to disk, it finishes processing in about 15 seconds and generates a meager 3KB file.
However, when trying to do the same with an in-memory VRT, it accuses unavailability of disk space:
>>> vrt = gdal.Warp('/vsimem/dem_4674.vrt', '/vsimem/dem_31837') ERROR 3: Free disk space available is 68643950592 bytes, whereas 84446749816 are at least necessary. You can disable this check by defining the CHECK_DISK_FREE_SPACE configuration option to FALSE.
I'm finding this advice of flagging check_disk_free_space to false a bit sketchy, so I'm reluctant to try it just like that. Is it really a problem of disk space? I have 1.3TB of free space, and moreover, why would an in-memory processing even require writing anything to disk? Is this related to virtual memory? And if so, why does this behaviour not present itself when writing the VRT to disk?
GDAL 2.2.1 64-bits, python 2.7.13 64-bits, Windows 10 64-bits