Re: [Libguestfs] [PATCH v4] v2v: Add --print-estimate option to print copy size estimate.
On Thursday, 23 August 2018 17:59:36 CEST Richard W.M. Jones wrote:
This option prints the estimated size of the data that will be
copied
from the source disk.
Currently this overestimates by the size of the qcow2 header, but for
real disk images that doesn't matter much.
For example:
$ virt-builder fedora-27
$ virt-v2v -i disk fedora-27.img -o null --print-estimate
[...]
virt-v2v: This guest has virtio drivers installed.
[ 44.0] Mapping filesystem data to avoid copying unused and blank areas
[ 44.5] Closing the overlay
1047920640
IMHO a better output is similar to what the --print-source prints --
so for example something like:
Estimation of the disks of the guest:
Total size: 100000
disk 1: 50000
disk 2: 50000
While the --machine-readable a JSON snippet:
{
"total": 100000,
"disks": [
50000,
50000
]
}
IMHO providing the sizes of all the disks is a good idea, so it is
possible to do better estimation on the progress, in case. Imagine
if a VM has a much bigger disk than the others, for example.
Also, I'd do the same no matter the number of disks, for coherency.
+ let json = Filename.temp_file "v2vmeasure"
".json" in
+ unlink_on_exit json;
+
+ let fd = Unix.openfile json [O_WRONLY; O_CREAT; O_TRUNC] 0o600 in
IMHO these can be replaced by Filename.open_temp_file +
Unix.descr_of_in_channel (still with unlink_on_exit).
--
Pino Toscano
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