Using GTP and glabel for ZFS arrays

Dan Langille dan at langille.org
Sat Jul 24 02:51:24 UTC 2010


On 7/23/2010 10:42 PM, Daniel O'Connor wrote:
>
> On 24/07/2010, at 11:55, Freddie Cash wrote:
>> It's theoretical as I have not investigated how to create sparse files
>> on FreeBSD, nor have I done this.  It's based on several posts to the
>> zfs-discuss mailing list where several people have done this on
>> OpenSolaris.
>
> FYI you would do..
> truncate -s 1T /tmp/fake-disk1
> mdconfig -a -t vnode -f /tmp/fake-disk1
>
> etc..
>
> Although you'd want to determine the exact size of your real disks from geom and use that.


  $ dd if=/dev/zero of=/tmp/sparsefile1.img bs=1 count=0 oseek=2000G
0+0 records in
0+0 records out
0 bytes transferred in 0.000025 secs (0 bytes/sec)

$ ls -l /tmp/sparsefile1.img
-rw-r--r--  1 dan  wheel  2147483648000 Jul 23 22:49 /tmp/sparsefile1.img

$ ls -lh /tmp/sparsefile1.img
-rw-r--r--  1 dan  wheel   2.0T Jul 23 22:49 /tmp/sparsefile1.img


-- 
Dan Langille - http://langille.org/


More information about the freebsd-stable mailing list