Date: Wed, 23 Jun 2010 11:54:48 +0100 From: Vincent Hoffman <vince@unsane.co.uk> To: freebsd-questions@freebsd.org Subject: Re: sparse image Message-ID: <4C21E7F8.2050802@unsane.co.uk> In-Reply-To: <4C21E163.70003@comclark.com> References: <4C21E163.70003@comclark.com>
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On 23/06/2010 11:26, Aiza wrote: > Is there an equivalent of the MAC sparseimage on FreeBSD? If you mean you would like to make a sparse file and attach it using mdconfg then dd if=/dev/zero of=/path/to/outfile bs=1M seek=1024 count=0 This will give you a sparse file that reports a gig in size, but only uses whats actually in use. you can then use mdconfig(8) to allow this to be partitioned formatted and mounted. Example below. see also http://www.freebsd.org/doc/en/books/handbook/disks-virtual.html although that example doesnt use a spare file. [root@ostracod /scratch/media]# dd if=/dev/zero of=foo.img bs=1M seek=1024 count=0 0+0 records in 0+0 records out 0 bytes transferred in 0.000066 secs (0 bytes/sec) [root@ostracod /scratch/media]# ls -lh foo.img -rw-r--r-- 1 root wheel 1.0G Jun 23 11:45 foo.img [root@ostracod /scratch/media]# du -h foo.img 48K foo.img [root@ostracod /scratch/media]# mdconfig -a -t vnode -f foo.img md0 [root@ostracod /scratch/media]# gpart create -s gpt md0 md0 created [root@ostracod /scratch/media]# gpart add -t freebsd-ufs md0 md0p1 added [root@ostracod /scratch/media]# newfs /dev/md0p1 /dev/md0p1: 1024.0MB (2097084 sectors) block size 16384, fragment size 2048 using 6 cylinder groups of 183.72MB, 11758 blks, 23552 inodes. super-block backups (for fsck -b #) at: 160, 376416, 752672, 1128928, 1505184, 1881440 [root@ostracod /scratch/media]# !ls ls -lh foo.img -rw-r--r-- 1 root wheel 1.0G Jun 23 11:46 foo.img [root@ostracod /scratch/media]# !du du -h foo.img 736K foo.img [root@ostracod /scratch/media]# mount /dev/md0p1 /mnt/foo/ [root@ostracod /scratch/media]# df -h | grep foo /dev/md0p1 989M 4.0K 910M 0% /mnt/foo [root@ostracod /scratch/media]# Hope this is helpful. Vince > _______________________________________________ > freebsd-questions@freebsd.org mailing list > http://lists.freebsd.org/mailman/listinfo/freebsd-questions > To unsubscribe, send any mail to > "freebsd-questions-unsubscribe@freebsd.org"
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