Re: [gentoo-user] How to shred without deleting /dev/*
Hi! On Mon, 29 Aug 2005 12:01:07 + (GMT) Michael Kintzios [EMAIL PROTECTED] wrote: I was blanking a floppy but when I ran: $ shred -u -v /dev/fd0 /dev/fd0 was dully deleted after the shred operation finished. Rebooting the machine relaunched udev which recreated fd0 (is there another way to avoid having to reboot)? Why was it deleted? Did you run the command as root? Is there a way of shredding a complete floppy (not just a file at a time) without removing the /dev/fd0 node? -- What's wrong with good old dd? How about $ dd if=/dev/zero of=/dev/fd0 You can also use /dev/random if it has to be more secure. For even more security run it multiple times in a loop. Cheers, Renat -- Probleme kann man niemals mit derselben Denkweise loesen, durch die sie entstanden sind. (Einstein) -- gentoo-user@gentoo.org mailing list
Re: Re: [gentoo-user] How to shred without deleting /dev/*
From:: Renat Golubchyk [EMAIL PROTECTED] To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] How to shred without deleting /dev/* Date: Mon, 29 Aug 2005 14:35:28 +0200 Why was it deleted? Did you run the command as root? Well, yes because when I run it as a plain user I am denied access: $ shred -u -v /dev/fd0 shred: /dev/fd0: Permission denied What's wrong with good old dd? How about $ dd if=/dev/zero of=/dev/fd0 You can also use /dev/random if it has to be more secure. For even more security run it multiple times in a loop. There's nothing wrong with dd, but I see no reason to create my own script to extend the basic dd functionality. I would rather use shred which does everything I want it to do - if only I can avoid the deletion if the device node itself. -- Regards, Mick Lycos email has now 300 Megabytes of free storage... Get it now at mail.lycos.co.uk
Re: [gentoo-user] How to shred without deleting /dev/*
Michael Kintzios: There's nothing wrong with dd, but I see no reason to create my own script to extend the basic dd functionality. I would rather use shred which does everything I want it to do - if only I can avoid the deletion if the device node itself. Why -u? From the man page: Delete FILE(s) if --remove (-u) is specified. The default is not to remove the files because it is common to operate on device files like /dev/hda, and those files usually should not be removed. BTW, which is your filesystem? From the man page again: CAUTION: Note that shred relies on a very important assumption: that the filesystem overwrites data in place. This is the traditional way to do things, but many modern filesystem designs do not satisfy this assumption. The following are examples of filesystems on which shred is not effective: * log-structured or journaled filesystems, such as those supplied with AIX and Solaris (and JFS, ReiserFS, XFS, Ext3, etc.) HTH Sergio -- gentoo-user@gentoo.org mailing list
Re: Re: [gentoo-user] How to shred without deleting /dev/*
From:: Sergio Polini [EMAIL PROTECTED] To: gentoo-user@lists.gentoo.org Subject: Re: [gentoo-user] How to shred without deleting /dev/* Date: Mon, 29 Aug 2005 15:09:36 +0200 Why -u? From the man page: Delete FILE(s) if --remove (-u) is specified. The default is not to remove the files because it is common to operate on device files like /dev/hda, and those files usually should not be removed. Oops, I brushed over it too fast and missed this rather important point! So, the -u option should NOT be used on devices. ;-) Thanks Sergio! -- Regards, Mick Lycos email has now 300 Megabytes of free storage... Get it now at mail.lycos.co.uk
Re: [gentoo-user] How to shred without deleting /dev/*
Michael Kintzios ([EMAIL PROTECTED]) scribbled: I was blanking a floppy but when I ran: $ shred -u -v /dev/fd0 /dev/fd0 was dully deleted after the shred operation finished. Rebooting the machine relaunched udev which recreated fd0 (is there another way to avoid having to reboot)? On the second floppy I thought of avoiding unwittingly deleting the fd0 node so I tried: $ shred -u -v /dev/fd0/ shred: /dev/fd0/: Not a directory Or: $ shred -u -v /dev/fd0/ shred: /dev/fd0/*: Not a directory Is there a way of shredding a complete floppy (not just a file at a time) without removing the /dev/fd0 node? # man shred [snip] -u, --remove truncate and remove file after overwriting -v, --verbose show progress -x, --exact do not round file sizes up to the next full block; this is the default for non-regular files -z, --zero add a final overwrite with zeros to hide shredding [snip] don't use '-u' on devices. hth, cooper. -- gentoo-user@gentoo.org mailing list
Re: [gentoo-user] How to shred without deleting /dev/*
On Monday 29 August 2005 07:01 am, Michael Kintzios wrote: Hi All, I was blanking a floppy but when I ran: $ shred -u -v /dev/fd0 /dev/fd0 was dully deleted after the shred operation finished. Rebooting the machine relaunched udev which recreated fd0 (is there another way to avoid having to reboot)? Very seldom is a reboot requried in Linux. You can always run /sbin/udevstart as root which will recreate the device nodes. On the second floppy I thought of avoiding unwittingly deleting the fd0 node so I tried: $ shred -u -v /dev/fd0/ shred: /dev/fd0/: Not a directory Or: $ shred -u -v /dev/fd0/ shred: /dev/fd0/*: Not a directory Is there a way of shredding a complete floppy (not just a file at a time) without removing the /dev/fd0 node? As for your original question about shred I can't really help since I don't use it. And have no need for floppies anymore either. Try man shred and see what the man pages say. -- Chris Linux 2.6.12-gentoo-r9 i686 AMD Athlon(tm) XP 23:19:33 up 4:38, 5 users, load average: 1.76, 1.50, 1.46 -- gentoo-user@gentoo.org mailing list
