I am not sure if this got sent to the group so I an fordwarding. This explains what is going on in the gtar code to cause gtar to seg fault. All the accolades should go to my SA partner Chapman Flack. He is in the process of sending this to bug-tar as suggested.
Robert ---- "Apparently under only some circumstances, gtar tries to use the old algorithm for finding the cwd. That fails beneath .zfs which is a sort of magical name that isn't there unless you're looking for it exactly. But it must just be a special combination of options that makes gtar try to do that, because in simple invocations it doesn't: hertz /homes % ls .z* # nobody here but us chickens... ls: No match. hertz /homes % cd .zfs # oh, you mean ME? hertz .zfs % cd snapshot/TODAY/jflack % gtar --create --file /dev/null bar # works fine Aha, it's the --listed-incremental option. This makes gtar want to create the snar file with names and metadata of files it sees: % gtar --create --file /dev/null --listed-incremental=/tmp/snar bar Segmentation fault The funny thing is, if I cd to ~ where it works... % cd ~ % gtar --create --file /dev/null --listed-incremental=/tmp/snar bar % ...and then look in /tmp/snar, it only contains relative paths... ...so it STILL doesn't explain why gtar even wants to get the cwd in that case, but it's clear from the truss that's what it's doing. One workaround might be to do a loopback mount of the desired snapshot onto some other path that's not beneath .zfs, and do the backup from there. -Chap" > -----Original Message----- > From: owner-amanda-us...@amanda.org [mailto:owner-amanda- > us...@amanda.org] On Behalf Of Nathan Stratton Treadway > Sent: Tuesday, May 04, 2010 2:45 PM > To: amanda-users@amanda.org > Subject: Re: runtar error that I do not understand > > > On Tue, May 04, 2010 at 13:03:09 -0500, Dustin J. Mitchell wrote: > > On Tue, May 4, 2010 at 12:27 PM, McGraw, Robert P > <rmcg...@purdue.edu> wrote: > > > I setup a lookback for the snapshot and now gtar seem to be > working. > > > > It sounds like you have a fairly good understanding of this problem > > now. Could you write up either a troubleshooting or How-To article > on > > the wiki? > > Also, you might want to send a bug report about this to the > bug-...@gnu.org list -- even if the underlying problem is that .zfs > doesn't behave normally, I suspect they'd be interested in knowing > about > the issue so that they can at least avoid having an abort-with-segfault > in that situation... > > http://www.gnu.org/software/tar/#maillists > > > Nathan > > ----------------------------------------------------------------------- > ----- > Nathan Stratton Treadway - natha...@ontko.com - Mid-Atlantic region > Ray Ontko & Co. - Software consulting services - > http://www.ontko.com/ > GPG Key: http://www.ontko.com/~nathanst/gpg_key.txt ID: > 1023D/ECFB6239 > Key fingerprint = 6AD8 485E 20B9 5C71 231C 0C32 15F3 ADCD ECFB 6239
