Re: rsync hanging on Access MDB file
Thanks for al the feedback. It sounds like an issue with the application owning the files - the client told me today that they are getting similar messages even though no users are connected. Regards, Des On 3 Mar 2009, at 00:36, Spiro Trikaliotis wrote: Hello Des, * On Mon, Mar 02, 2009 at 11:41:05PM -0800 Des Dougan wrote: rsync: connection unexpectedly closed (449058 bytes received so far) [receiver] rsync error: error in rsync protocol data stream (code 12) at io.c(635) [receiver=3.0.2] rsync: connection unexpectedly closed (237 bytes received so far) [generator] rsync error: unexplained error (code 255) at io.c(635) [generator=3.0.2] The error occurs each time on the same Access database file (part of the application suite the server was installed for). I know this behaviour for other file types: It happens if these files are either hold open (Outlook .pst files come to mind), or even modified while rsync is in progress. Thus, can you really rule out that noone else is accessing this file while rsync is taking place? My experience with Access is rather old (Access 1.1 and 2.0, some 15 years ago), but for these ancient versions, every time someone accesses this database, he opens the .mdb file himself in a shared manner. Thus, even if nothing is running on the server, there might be some remote user that is still accessing the DB. Regards, Spiro. -- Spiro R. Trikaliotis http://opencbm.sf.net/ http://www.trikaliotis.net/ http://www.viceteam.org/ -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/ -- Des Dougan, Principal Dougan Consulting Group Inc. Office: 604-628-5434 Cell: 604-866-2848 Email: des at DouganConsulting dot com www.DouganConsulting.com Peace of Mind, One Computer at a Time. -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: rsync hanging on Access MDB file
On Tue, Mar 3, 2009 at 2:01 PM, Spiro Trikaliotis wrote: > Hello Greg, > > * On Tue, Mar 03, 2009 at 12:26:17PM -0500 Greg Freemyer wrote: >> On Tue, Mar 3, 2009 at 12:13 PM, Spiro Trikaliotis > [shadow copies on Windows] >> I don't use Access, but in general good applications should support >> being quiesced. They do that by registering with the VSS service. >> Then when a shadow copy is requested, vss first notifies all >> registered apps to quiesce themselves. > > Yes, I forgot about that. This might work, at least with newer versions > of Access. > > There might be a caveat, though: You can remotely use MS Access to > access an MDB file on a file server. You can even do it multiple times, > having x instances of MS Access access just one file on a remote server. > Can a remote application register with the VSS service on a completely > different machine? No idea, but given vss is standard microsoft stuff, it is very feasible it can. FYI: registering like this is one place I think Windows is ahead of Linux. And Microsoft has been supporting the whole process since they brought out vss way back with Win2003. Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: rsync hanging on Access MDB file
Hello Greg, * On Tue, Mar 03, 2009 at 12:26:17PM -0500 Greg Freemyer wrote: > On Tue, Mar 3, 2009 at 12:13 PM, Spiro Trikaliotis [shadow copies on Windows] > I don't use Access, but in general good applications should support > being quiesced. They do that by registering with the VSS service. > Then when a shadow copy is requested, vss first notifies all > registered apps to quiesce themselves. Yes, I forgot about that. This might work, at least with newer versions of Access. There might be a caveat, though: You can remotely use MS Access to access an MDB file on a file server. You can even do it multiple times, having x instances of MS Access access just one file on a remote server. Can a remote application register with the VSS service on a completely different machine? Regards, Spiro. -- Spiro R. Trikaliotis http://opencbm.sf.net/ http://www.trikaliotis.net/ http://www.viceteam.org/ -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: rsync hanging on Access MDB file
On Tue, Mar 3, 2009 at 12:13 PM, Spiro Trikaliotis > Hello Greg, > > * On Tue, Mar 03, 2009 at 10:20:52AM -0500 Greg Freemyer wrote: >> On Tue, Mar 3, 2009 at 3:36 AM, Spiro Trikaliotis >> wrote: > > Please do not cite mail addresses! > >> > Thus, can you really rule out that noone else is accessing this file >> > while rsync is taking place? My experience with Access is rather old >> > (Access 1.1 and 2.0, some 15 years ago), but for these ancient versions, >> > every time someone accesses this database, he opens the .mdb file >> > himself in a shared manner. Thus, even if nothing is running on the >> > server, there might be some remote user that is still accessing the DB. > [...] >> The above is exactly why VSS was created by Microsoft. > > Unfortunately, if you take a shadow copy of an open file, you might end > with a correctly copied (or rsync'ed) file which is broken. You must be > sure that noone is accessing the file at the moment you take the shadow > copy. I don't use Access, but in general good applications should support being quiesced. They do that by registering with the VSS service. Then when a shadow copy is requested, vss first notifies all registered apps to quiesce themselves. Once all registered apps are quiesced, the shadow copy is created. The whole purpose of the process is to ensure logically consistent data is captured in the backup. NTbackup from Microsoft is using vss to make its backups, so I would be very surprised if Access is not registering itself and fitting into Microsoft's master plan. Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: rsync hanging on Access MDB file
Hello Greg, * On Tue, Mar 03, 2009 at 10:20:52AM -0500 Greg Freemyer wrote: > On Tue, Mar 3, 2009 at 3:36 AM, Spiro Trikaliotis > wrote: Please do not cite mail addresses! > > Thus, can you really rule out that noone else is accessing this file > > while rsync is taking place? My experience with Access is rather old > > (Access 1.1 and 2.0, some 15 years ago), but for these ancient versions, > > every time someone accesses this database, he opens the .mdb file > > himself in a shared manner. Thus, even if nothing is running on the > > server, there might be some remote user that is still accessing the DB. [...] > The above is exactly why VSS was created by Microsoft. Unfortunately, if you take a shadow copy of an open file, you might end with a correctly copied (or rsync'ed) file which is broken. You must be sure that noone is accessing the file at the moment you take the shadow copy. Of course, this operation can limit the time span you have to make sure noone is accessing the file. Here, you are right. Regards, Spiro. -- Spiro R. Trikaliotis http://opencbm.sf.net/ http://www.trikaliotis.net/ http://www.viceteam.org/ -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: rsync hanging on Access MDB file
On Tue, Mar 3, 2009 at 3:36 AM, Spiro Trikaliotis wrote: > Hello Des, > > * On Mon, Mar 02, 2009 at 11:41:05PM -0800 Des Dougan wrote: > >> rsync: connection unexpectedly closed (449058 bytes received so far) >> [receiver] >> rsync error: error in rsync protocol data stream (code 12) at io.c(635) >> [receiver=3.0.2] >> rsync: connection unexpectedly closed (237 bytes received so far) >> [generator] >> rsync error: unexplained error (code 255) at io.c(635) [generator=3.0.2] >> >> The error occurs each time on the same Access database file (part of the >> application suite the server was installed for). > > I know this behaviour for other file types: It happens if these files > are either hold open (Outlook .pst files come to mind), or even modified > while rsync is in progress. > > Thus, can you really rule out that noone else is accessing this file > while rsync is taking place? My experience with Access is rather old > (Access 1.1 and 2.0, some 15 years ago), but for these ancient versions, > every time someone accesses this database, he opens the .mdb file > himself in a shared manner. Thus, even if nothing is running on the > server, there might be some remote user that is still accessing the DB. > > Regards, > Spiro. The above is exactly why VSS was created by Microsoft. I brought up cygwin support of vss a week or two ago. Not perfect, but you should be able to make it work by making some win32 calls to setup the shadow copy, then rsync from there and make another win32 call to delete the shadow copy when your done. I found the thread at: http://www.mail-archive.com/cygwin@cygwin.com/msg94495.html If you have more questions, it might make sense to reply to those messages. Or at least cut & paste some of it here. Greg -- Greg Freemyer Litigation Triage Solutions Specialist http://www.linkedin.com/in/gregfreemyer First 99 Days Litigation White Paper - http://www.norcrossgroup.com/forms/whitepapers/99%20Days%20whitepaper.pdf The Norcross Group The Intersection of Evidence & Technology http://www.norcrossgroup.com -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
Re: rsync hanging on Access MDB file
Hello Des, * On Mon, Mar 02, 2009 at 11:41:05PM -0800 Des Dougan wrote: > rsync: connection unexpectedly closed (449058 bytes received so far) > [receiver] > rsync error: error in rsync protocol data stream (code 12) at io.c(635) > [receiver=3.0.2] > rsync: connection unexpectedly closed (237 bytes received so far) > [generator] > rsync error: unexplained error (code 255) at io.c(635) [generator=3.0.2] > > The error occurs each time on the same Access database file (part of the > application suite the server was installed for). I know this behaviour for other file types: It happens if these files are either hold open (Outlook .pst files come to mind), or even modified while rsync is in progress. Thus, can you really rule out that noone else is accessing this file while rsync is taking place? My experience with Access is rather old (Access 1.1 and 2.0, some 15 years ago), but for these ancient versions, every time someone accesses this database, he opens the .mdb file himself in a shared manner. Thus, even if nothing is running on the server, there might be some remote user that is still accessing the DB. Regards, Spiro. -- Spiro R. Trikaliotis http://opencbm.sf.net/ http://www.trikaliotis.net/ http://www.viceteam.org/ -- Unsubscribe info: http://cygwin.com/ml/#unsubscribe-simple Problem reports: http://cygwin.com/problems.html Documentation: http://cygwin.com/docs.html FAQ: http://cygwin.com/faq/
