On 25/05/10 15:32, Richard W.M. Jones wrote: > The manpage for truncate says: > > Note that the -r and -s options are mutually exclusive. > > and indeed you cannot have both: > > $ truncate -r /tmp/ref -s +10M /tmp/new > truncate: you must specify one of `--size' or `--reference' > > We suggest using the 'truncate' command in the 'virt-resize' > documentation[1]. We want users to create a file which is the size of > an existing file + some extra amount. Naturally this would be: > > truncate -r old-disk.img -s +1G new-disk.img > > but this does not work and we have to suggest that users use two > separate 'truncate' commands[2].
That seems like a worthwhile change. I.E. allow relative --size with -r. I'll cook up a patch in the morning. > Related to this feature request, it would be nice if you could suffix > a size with a % sign to indicate that you want to increase a file by a > certain percentage of the old or reference size, eg: > > truncate -r old-disk.img -s +10% new-disk.img > > truncate -r old-disk.img -s 110% new-disk.img I'm a little less enthusiastic about the need for that. Given how awkward it is to achieve then I might do it (as a separate patch). Here's how you'd might do it handling overflow currently: truncate -s$(echo "$(stat --format %s file) * 1.1" | bc | cut -d. -f1) file I guess it would be OK to truncate the result rather than round to nearest? cheers, Pádraig.
