RE: Shouldn't GNU tar be ignoring /proc with --one-file-system?
> -Original Message- > From: owner-freebsd-questi...@freebsd.org [mailto:owner-freebsd- > questi...@freebsd.org] On Behalf Of Daniel Staal > Sent: Friday, November 18, 2011 18:00 > To: freebsd-questions@freebsd.org > Subject: Re: Shouldn't GNU tar be ignoring /proc with --one-file- > system? > > > On Fri, November 18, 2011 10:34 am, Kirk Strauser wrote: > > I use Amanda to make nightly backups of a bunch of servers using GNU > tar. > > However, gtar doesn't seem to respect its --one-file-system flag with > > /proc. Amanda runs a variation of this command: > > > > # /usr/local/bin/gtar --create --file - --directory / > > --one-file-system --sparse --ignore-failed-read --totals . > > /dev/null > > /usr/local/bin/gtar: ./proc: file changed as we read it > > > > Before I file a bug report, can anyone think of a legitimate reason > why > > gtar would be touching /proc at all? > > Just a guess, really but: > > /proc is a file on /. /proc/* are files on /proc. The former is still > on > the root filesystem (if only as a directory stub to be used as a > mountpoint), so reading it isn't leaving that filesystem. Reading > anything *in* it would be. > > Just a thought. > However, the file /proc on fs / should not be changing since a filesystem /proc is mounted over it. The message "./proc: file changed as we read it" indicates whatever /proc it is trying to read did change... -- Regards, T. Koeman, MTh/BSc/BPsy; Technical Monk MediaMonks B.V. (www.mediamonks.com) Please quote relevant replies in correspondence. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
Kirk Strauser wrote: > On Nov 18, 2011, at 11:27 AM, Robert Bonomi wrote: > > > See the output of 'mount(8)' for the names of all the mounted > > filesystems on your machine. > > $ mount | grep proc > procfs on /proc (procfs, local) > > > *NOTE*WELL* that '/proc' is *not* a separate filesystem. It > > is merely a _directory_ with a bunch of 'special' files in it. > > I'm confused here. In what way isn't /proc a separate filesystem? > It's even called "procfs". It's Bonomi who is confused. I suspect he doesn't have procfs configured -- so of course its mountpoint is just a directory -- *on his system*. The OP _does_ have procfs configured, or the question wouldn't have arisen. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
On Fri, 18 Nov 2011, Kirk Strauser wrote: On Nov 18, 2011, at 11:27 AM, Robert Bonomi wrote: See the output of 'mount(8)' for the names of all the mounted filesystems on your machine. $ mount | grep proc procfs on /proc (procfs, local) *NOTE*WELL* that '/proc' is *not* a separate filesystem. It is merely a _directory_ with a bunch of 'special' files in it. I'm confused here. In what way isn't /proc a separate filesystem? It's even called "procfs". I just went to an 8.1 system as root and did: umount /proc and /proc dismounted leaving an empty directory in route. I then went mount /proc and /proc was mounted again, using the parameters in /etc/fstab. Surely that means that going from / to /proc is "crossing a filesystem boundary". To me that suggests it is a separate filesystem, and typically /proc is filled with stuff that you wouldn't want to recurse through, so I wouldn't think it a good candidate for special casing as non-mounted. Daniel Feenberg NBER ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org" ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
On Fri, Nov 18, 2011 at 9:27 AM, Matthew Seaman wrote: > I find it quite astonishing that /proc would deliberately behave > differently to *every other* filesystem available. The mountpoint > should belong to the filesystem mounted on it. I have an idea what you mean by "belong to" in this case and - if I'm right, you're wrong :-) A mount point has an inode in the parent filesystem, right? Good, glad we cleared that up. Unless you set the 'nodump' flag, and tell tar/gtar/tarsnap/dump to honor the flag, the archive will have an entry for the mount point. The 'one-file-system' flags tells gtar not to traverse mount points, but it will certainly see the mount point and include it in the archive, along with its modes, flags, atime, mtime, etc. etc. If those changed between the time if took a peek at the directory and the time it attempted to include it in the archive, you'll see those advisory warnings (which may be ignored in this case). ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
On Nov 18, 2011, at 11:27 AM, Robert Bonomi wrote: > See the output of 'mount(8)' for the names of all the mounted filesystems on > your machine. $ mount | grep proc procfs on /proc (procfs, local) > > *NOTE*WELL* that '/proc' is *not* a separate filesystem. It is merely a > _directory_ with a bunch of 'special' files in it. I'm confused here. In what way isn't /proc a separate filesystem? It's even called "procfs". ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
On 18/11/2011 17:18, Michael Sierchio wrote: > On Fri, Nov 18, 2011 at 8:59 AM, Daniel Staal wrote: > >> > /proc is a file on /. /proc/* are files on /proc. The former is still on >> > the root filesystem (if only as a directory stub to be used as a >> > mountpoint), so reading it isn't leaving that filesystem. Reading >> > anything *in* it would be. >> > >> > Just a thought. > And a good one. Yes, that's it. It isn't crossing the mount point, > but the mount point is part of the root filesystem. I find it quite astonishing that /proc would deliberately behave differently to *every other* filesystem available. The mountpoint should belong to the filesystem mounted on it. Cheers, Matthew -- Dr Matthew J Seaman MA, D.Phil. 7 Priory Courtyard Flat 3 PGP: http://www.infracaninophile.co.uk/pgpkey Ramsgate JID: matt...@infracaninophile.co.uk Kent, CT11 9PW signature.asc Description: OpenPGP digital signature
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
> From owner-freebsd-questi...@freebsd.org Fri Nov 18 09:36:09 2011 > From: Kirk Strauser > Date: Fri, 18 Nov 2011 09:34:18 -0600 > To: FreeBSD Questions ML > Subject: Shouldn't GNU tar be ignoring /proc with --one-file-system? > > I use Amanda to make nightly backups of a bunch of servers using GNU tar. Howe > ver, gtar doesn't seem to respect its --one-file-system flag with /proc. Amand > a runs a variation of this command: Don't blame the software. It is just doing *exactly* what you told it to. :) > > # /usr/local/bin/gtar --create --file - --directory / --one-file-system > --sparse --ignore-failed-read --totals . > /dev/null > /usr/local/bin/gtar: ./proc: file changed as we read it > > Before I file a bug report, can anyone think of a legitimate reason why gtar > would be touching /proc at all? Yup. You (or more properly, Amanda) _told_ it to. See the output of 'mount(8)' for the names of all the mounted filesystems on your machine. *NOTE*WELL* that '/proc' is *not* a separate filesystem. It is merely a _directory_ with a bunch of 'special' files in it. The 'error message' is accurate -- but it is _just_ a 'warning', and -- in *this* circumstance -- _totally_ innocuous. If you want to suppress generation of that error, simply add an '--exclude' for /proc to the Amanda run. ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
On Fri, Nov 18, 2011 at 8:59 AM, Daniel Staal wrote: > /proc is a file on /. /proc/* are files on /proc. The former is still on > the root filesystem (if only as a directory stub to be used as a > mountpoint), so reading it isn't leaving that filesystem. Reading > anything *in* it would be. > > Just a thought. And a good one. Yes, that's it. It isn't crossing the mount point, but the mount point is part of the root filesystem. If you really want it to ignore the mount point itself, set the nodump flag and tell gtar to honor it: > chflags nodump /proc > gtar --nodump ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Re: Shouldn't GNU tar be ignoring /proc with --one-file-system?
On Fri, November 18, 2011 10:34 am, Kirk Strauser wrote: > I use Amanda to make nightly backups of a bunch of servers using GNU tar. > However, gtar doesn't seem to respect its --one-file-system flag with > /proc. Amanda runs a variation of this command: > > # /usr/local/bin/gtar --create --file - --directory / > --one-file-system --sparse --ignore-failed-read --totals . > /dev/null > /usr/local/bin/gtar: ./proc: file changed as we read it > > Before I file a bug report, can anyone think of a legitimate reason why > gtar would be touching /proc at all? Just a guess, really but: /proc is a file on /. /proc/* are files on /proc. The former is still on the root filesystem (if only as a directory stub to be used as a mountpoint), so reading it isn't leaving that filesystem. Reading anything *in* it would be. Just a thought. Daniel T. Staal --- This email copyright the author. Unless otherwise noted, you are expressly allowed to retransmit, quote, or otherwise use the contents for non-commercial purposes. This copyright will expire 5 years after the author's death, or in 30 years, whichever is longer, unless such a period is in excess of local copyright law. --- ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
Shouldn't GNU tar be ignoring /proc with --one-file-system?
I use Amanda to make nightly backups of a bunch of servers using GNU tar. However, gtar doesn't seem to respect its --one-file-system flag with /proc. Amanda runs a variation of this command: # /usr/local/bin/gtar --create --file - --directory / --one-file-system --sparse --ignore-failed-read --totals . > /dev/null /usr/local/bin/gtar: ./proc: file changed as we read it Before I file a bug report, can anyone think of a legitimate reason why gtar would be touching /proc at all? Kirk ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to "freebsd-questions-unsubscr...@freebsd.org"
