Klemens Nanni(k...@openbsd.org) on 2019.11.30 01:44:48 +0100:
> Just like on amd64 with vmctl(8), I want to be able to easily create
> disk images.
>
> ldomctl(8) currently advises to use dd(1), those files are not sparse
> either so creating big images may take a lot of time and the process
> tends to be error prone.
you can create sparse files with dd using seek=<large-num>
dd if=/dev/zero of=blarf bs=1 count=0 seek=512M
no opinion on the diff.
> `ldomctl create-vdisk -s size file' behaves like
> `vmctl create -s size file' except that size is parsed by scan_scaled(3)
> and not assumed to be megabytes, e.g.
>
> $ ldomctl create-vdisk -s 8G ~/guest01.img
> t4-2$ ./obj/ldomctl create-vdisk -s 8G ~/guest01.img
> t4-2$ ls -l ~/guest01.img
> -rw------- 1 kn kn 8589934592 Nov 30 01:42 /home/kn/guest01.img
> t4-2$ du ~/guest01.img
> 96 /home/kn/guest01.img
>
> Feedback? OK?
>
>
> Index: ldom.conf.5
> ===================================================================
> RCS file: /cvs/src/usr.sbin/ldomctl/ldom.conf.5,v
> retrieving revision 1.7
> diff -u -p -r1.7 ldom.conf.5
> --- ldom.conf.5 28 Nov 2019 18:40:42 -0000 1.7
> +++ ldom.conf.5 29 Nov 2019 23:56:07 -0000
> @@ -59,8 +59,9 @@ for a list of OpenPROM variables.
> The specified file is used to back a virtual disk of the guest
> domain.
> .Ar file
> -can be a block device node or a disk image file created with
> -.Xr dd 1 .
> +can be a block device node or a disk image file created with the
> +.Cm create-vdisk
> +command.
> This keyword can be used multiple times.
> .It Ic vnet Op Brq Ar keyword Ns = Ns Ar value ...
> Assign a
> Index: ldomctl.8
> ===================================================================
> RCS file: /cvs/src/usr.sbin/ldomctl/ldomctl.8,v
> retrieving revision 1.18
> diff -u -p -r1.18 ldomctl.8
> --- ldomctl.8 28 Nov 2019 18:03:33 -0000 1.18
> +++ ldomctl.8 29 Nov 2019 23:47:01 -0000
> @@ -34,6 +34,16 @@ information about domains running on the
> .Pp
> The following commands are available:
> .Bl -tag -width Ds
> +.It Cm create-vdisk Fl s Ar size Ar file
> +Create a virtual disk image with the specified
> +.Ar file
> +path and
> +.Ar size ,
> +in bytes.
> +.Ar size
> +can be specified with a human-readable scale, using the format described in
> +.Xr scan_scaled 3 ,
> +e.g. 512M.
> .It Cm console Ar domain
> Using
> .Xr cu 1
> @@ -119,8 +129,8 @@ openbsd [next]
> .Pp
> Create a virtual disk image for each guest domain:
> .Bd -literal -offset indent
> -# dd if=/dev/zero of=/home/puffy/vdisk0 bs=1m count=8192
> -# dd if=/dev/zero of=/home/salmah/vdisk0 bs=1m count=8192
> +# ldomctl create-vdisk -s 8G /home/puffy/vdisk0
> +# ldomctl create-vdisk -s 8G /home/salmah/vdisk0
> .Ed
> .Pp
> The minirootfs install media can be used to boot guest domains:
> Index: ldomctl.c
> ===================================================================
> RCS file: /cvs/src/usr.sbin/ldomctl/ldomctl.c,v
> retrieving revision 1.27
> diff -u -p -r1.27 ldomctl.c
> --- ldomctl.c 28 Nov 2019 18:40:42 -0000 1.27
> +++ ldomctl.c 30 Nov 2019 00:40:49 -0000
> @@ -18,12 +18,15 @@
>
> #include <sys/types.h>
> #include <sys/ioctl.h>
> +#include <sys/stat.h>
> #include <err.h>
> +#include <errno.h>
> #include <fcntl.h>
> #include <stdlib.h>
> #include <stdio.h>
> #include <string.h>
> #include <unistd.h>
> +#include <util.h>
>
> #include "ds.h"
> #include "hvctl.h"
> @@ -53,6 +56,7 @@ void list(int argc, char **argv);
> void list_io(int argc, char **argv);
> void xselect(int argc, char **argv);
> void delete(int argc, char **argv);
> +void create_vdisk(int argc, char **argv);
> void guest_start(int argc, char **argv);
> void guest_stop(int argc, char **argv);
> void guest_panic(int argc, char **argv);
> @@ -67,6 +71,7 @@ struct command commands[] = {
> { "list-io", list_io },
> { "select", xselect },
> { "delete", delete },
> + { "create-vdisk", create_vdisk },
> { "start", guest_start },
> { "stop", guest_stop },
> { "panic", guest_panic },
> @@ -117,6 +122,9 @@ main(int argc, char **argv)
> if (cmdp->cmd_name == NULL)
> usage();
>
> + if (strcmp(argv[0], "create-vdisk") == 0)
> + goto skip_hv;
> +
> hv_open();
>
> /*
> @@ -153,6 +161,7 @@ main(int argc, char **argv)
> add_guest(prop->d.arc.node);
> }
>
> +skip_hv:
> (cmdp->cmd_func)(argc, argv);
>
> exit(EXIT_SUCCESS);
> @@ -165,6 +174,7 @@ usage(void)
> "\t%1$s download directory\n"
> "\t%1$s dump|list|list-io\n"
> "\t%1$s init-system file\n"
> + "\t%1$s create-vdisk -s size file\n"
> "\t%1$s console|panic|start|status|stop [domain]\n", getprogname());
> exit(EXIT_FAILURE);
> }
> @@ -347,6 +357,48 @@ delete(int argc, char **argv)
> ds_conn_handle(dc);
>
> mdstore_delete(dc, argv[1]);
> +}
> +
> +void
> +create_vdisk(int argc, char **argv)
> +{
> + int ch, fd, save_errno;
> + long long imgsize;
> + const char *imgfile_path;
> +
> + while ((ch = getopt(argc, argv, "s:")) != -1) {
> + switch (ch) {
> + case 's':
> + if (scan_scaled(optarg, &imgsize) == -1)
> + err(1, "invalid size: %s", optarg);
> + break;
> + default:
> + usage();
> + }
> + }
> + argc -= optind;
> + argv += optind;
> +
> + if (argc != 1)
> + usage();
> +
> + imgfile_path = argv[0];
> +
> + /* Refuse to overwrite an existing image */
> + if ((fd = open(imgfile_path, O_RDWR | O_CREAT | O_TRUNC | O_EXCL,
> + S_IRUSR | S_IWUSR)) == -1)
> + err(1, "ftruncate");
> +
> + /* Extend to desired size */
> + if (ftruncate(fd, (off_t)imgsize) == -1) {
> + save_errno = errno;
> + close(fd);
> + unlink(imgfile_path);
> + errno = save_errno;
> + err(1, "ftruncate");
> + }
> +
> + close(fd);
> }
>
> void
>
