Keeping filesystem images sparse

Filesystem images in local files can be used by many PC emulators and virtual machines (user-mode Linux, QEMU and Xen, to name but three). Typically these filesystems are created as sparse files using commands like: dd if=/dev/zero of=fs.image bs=1024 seek=2000000 count=0 /sbin/mke2fs fs.image where the enormous seek value causes dd to move forward by 2GB before writing nothing at all. This result

[iww]

"The utility also works on ext3 or ext4 filesystems." zerofreeはext4にも対応

[tmatsuu]

メモ