BU Mailing List Archive


Subject: bu mailing list

 Date: Sat, 23 Mar 2002 22:30:12 -0600
 From: Vincent Stemen <bu@hightek.org>
 Hi everybody.

 This is just a curtesy note to let you know I finally set up a mailing
 list for bu.  I think I got everybody on it that has emailed me about
 bu expressing significant interest in the project.  Most have asked to
 be put on it once I finally set one up.  I will post new release
 announcements to this list as well as answer questions.  Hopefully,
 this will allow everybody to help each other if I get busy and am slow
 about responding :-).

 It is a simple list that does not require one to be subscribed to post
 to it yet.  Only to received messages from it.  Everybody that
 receives this message is already subscribed.  I will eventually get
 around to setting up real mailing list software such as majordomo.

 Please accept my apologies if you do not want on the list.  Send me an
 un-subscribe note and I will remove you.  Otherwise, please use the
 list for future questions/bug reports so that everybody may benefit
 from it unless you really feal something merits private
 communications.

 Regards,
 Vincent


Subject: bu CDRW status

 Date: Wed, 27 Mar 2002 02:08:36 -0600
 From: Vincent Stemen <bu@hightek.org>
 On Sat, Mar 23, 2002 at 01:20:22PM +0100, Alain Cochard wrote:
 > PS:  Still dying for version 3!!

 The CDRW dump capability is taking longer than I expected.  First I
 had to re-write a bunch of the code because it turned out that GNU tar
 is buggy when it comes to restoring from pipes.  I spoke with the
 maintainer about it and he does not have the time right now to fix it
 because of higher priority bugs.  Tar does not do multi-volume with
 compression so I am writing more sophisticated code to handle it.  I
 switched to other techniques to create the archive which involves
 forking a process into the background to find the files and stream
 them to another process that simultaneously generates the archives,
 breaking up the volumes as needed.  I want high performance without
 having to wait on one stage to complete before the next one starts.  I
 ran into some technical difficulties (do to a small gap in my
 knowledge in perl that nailed me) getting the streams to work the way
 I want them to.  I think I now have it mostly resolved so it should
 not be much longer.  It turned out that the new technique actually is
 better anyway because I came up with a way to vary the amount of data
 that goes on each volume depending on the compression ratio rather
 than putting a fixed amount of pre-compressed data on each volume.


Subject: Re: bu CDRW status

 Date: Wed, 27 Mar 2002 09:47:50 +0100
 From: "Gabor Z. Papp" <gzp@myhost...>
 * Vincent Stemen <bu@hightek.org>:

 | On Sat, Mar 23, 2002 at 01:20:22PM +0100, Alain Cochard wrote:
 | > PS:  Still dying for version 3!!
 | 
 | The CDRW dump capability is taking longer than I expected.  First I
 | had to re-write a bunch of the code because it turned out that GNU tar
 | is buggy when it comes to restoring from pipes.  I spoke with the
 | maintainer about it and he does not have the time right now to fix it

 Try with http://www.fokus.gmd.de/research/cc/glone/employees/joerg.schilling/private/man/star.html


Subject: Re: B U question

 Date: Fri, 17 May 2002 12:40:11 -0500
 From: Vincent Stemen <bu@hightek.org>
 On Fri, May 17, 2002 at 10:32:58AM +0200, Dirk Schouten wrote:
 > Hello Vincent,
 > 
 > Your program is working fine at our primary school.
 > We noticed one thing that's a bit unfortunate for us.
 > As far as I can see B U does not copy empty directories.
 > We have a system in which every group in school is just one user in /home.
 > Every pupil in a group has a directory of her/his own. When directories
 > remain empty and are not copied, we have to do extra work in case of a
 > crash, i.e. finding out which directories are missing and recreating them.
 > 
 > Is this a suggestion for improvement? Or a bug report?? Or ...?
 > 

 Yes, I am aware of this.  I have received at least one other email
 about it.  It is on the to do list to be fixed and should be fixed
 sometime in the next few beta releases.  It is an architectural
 problem with the way bu uses "cp".  I plan to re-write part of the
 code in perl in a way which will fix this and, I expect, will
 dramatically improve the performance.

 The new CDRW dump features in the version about to be released dumps
 empty directories if that is helpful to you in the meantime.

 Vincent

 > Have a nice weekend,
 > Dirk
 > _________________________________________
 > Dirk Schouten
 > 
 > Media Action Projects
 > http://utopia.knoware.nl/users/schoutdi
 > Take a peek at the NEWS and REVIEWS sections!


Subject: Re: B U question

 Date: Sat, 18 May 2002 21:07:50 -0500
 From: Vincent Stemen <bu@hightek.org>
 On Fri, May 17, 2002 at 10:57:41PM +0200, Dirk Schouten wrote:
 > Hi Vincent,

 > A few comments from a computer and UNIX newbie, looking to B U from his own
 > perspective:
 > 
 > >Yes, I am aware of this.  I have received at least one other email
 > >about it.  It is on the to do list to be fixed and should be fixed
 > >sometime in the next few beta releases.  
 > As you can imagine, I look forward to it!
 > 
 > >It is an architectural
 > >problem with the way bu uses "cp".  I plan to re-write part of the
 > >code in perl in a way which will fix this and, I expect, will
 > >dramatically improve the performance.

 > One of the things I like about B U is that it's not in Perl.
 > So it runs on any Linux/UNIX.

 All Linux and BSD systems I have seen are distributed with Perl now
 days, and I have not heard of any other Unix platforms that Perl
 cannot run on, so I do not expect this to be an issue.  The existing
 usage and behavior of the NFS backup features of bu will not change
 if I re-write any of it in perl, so you should not notice any
 difference other than performance.

 I wrote all the new CDRW code in Perl because a lot of the code was
 just to complex to try to implement in shell script.

 > And the performance improvement?? Better copies? Faster? Here the program
 > works at night, so we do not need performance improvement.

 It should be considerably faster, for one, because it will be copying
 the files as they are being found.  Currently, bu runs "find" on each
 specified directory and generates a list of every file to be backed up
 and filters it through the Exclude list before it starts copying any
 files from that directory.  Not only that, in the new CDRW Perl code,
 I exclude entire directories from being traversed during the find
 process if they are in the Exclude list.  With the existing shell
 script code for FS backups using find, directories that are excluded
 still get traversed by find and every file is screened.  This is far
 more overhead.

 I have already written the Perl code to do most of this for the CDRW
 features and the performance is pretty good.  Also, for NFS backups,
 bu currently runs "cp" on every file.  If it turns out not to be too
 difficult to retain all the file attributes, I also may do the copying
 directly with Perl which should be faster than running cp on every
 file.  Another advantage is that it would also eliminate the need to
 have GNU fileutils installed on BSD.

 > 
 > >The new CDRW dump features in the version about to be released do dump
 > >empty directories if that is helpful to you in the meantime.

 > To be honest, this does not help us. On the contrary! 
 > We like a program that just backs up. No untarring, no endless searches for
 > files, just what you write in your white paper. The strength of the program
 > is it's simplicity. It backs up, nothing more, nothing less. If a directory
 > is empty, it's the problem (or the pleasure) of the user. I hope you can
 > understand this.

 Absolutely.  Don't worry, I have no intention of removing any of the
 existing features.  The CDRW dump features are in addition because we
 needed to be able to periodically dump our backup filesystem to
 removable media to keep off site and we could find no other suitable
 tools to do this.  Especially none that run on both FreeBSD and Linux.
 They are meant to compliment bu's existing features.  You can continue
 running bu as you have been without ever using the new features.

 > Would it be an easy adjustment in the program to have it backup
 > _everything_. If not, we live with it and ask the pupils to put anything in
 > their directories.
 >

 I did not originally think it would be easy to include empty
 directories with the existing code without re-writing part of the
 backup() routine in Perl.  However, I was looking at the code again
 today and I think I came up with a way to add this ability with the
 existing shell script.  I will experiment with it as soon as I get the
 chance.  At least that would fix the immediate problem whether the
 speed improves or not, and I can go back later on to improve it with
 Perl.

 Vincent


Subject: B U 'improvement'.

 Date: Sun, 19 May 2002 14:57:20 +0200
 From: Dirk Schouten <schoutdi@knoware...>
 Hi Vincent,
 Thanks for your quick reply.

 <snip>
 >> Would it be an easy adjustment in the program to have it backup
 >> _everything_. If not, we live with it and ask the pupils to put anything in
 >> their directories.
 >> 
 >
 >I did not originally think it would be easy to include empty
 >directories with the existing code without re-writing part of the
 >backup() routine in Perl.  However, I was looking at the code again
 >today and I think I came up with a way to add this ability with the
 >existing shell script.  I will experiment with it as soon as I get the
 >chance.  At least that would fix the immediate problem whether the
 >speed improves or not, and I can go back later on to improve it with
 >Perl.

 As you can imagine, we appreciate your idea (when is it ready...:-)).
 And/but, there is more to it.

 We now use your free program. In our school I strongly promote the idea
 that, although we use as much  'free software' as possible, this certainly
 does not mean that, to reverse quoting one of the GNU/Linux guru's, we do
 not want to pay or to contribute to free software. In our opinion it is a
 necessary way to keep developers developing, to get improvements, and in
 the end to ensure the continuated existence of free software.
 We have a limited budget (being a normal primary school in Holland) and are
 quite willing to pay for the improvement we ask for.
 Maybe we should further discuss this topic off-list or maybe it is a very
 good idea to keep it public, I do not know.
 Looking forward to hearing from you,

 Hope you enjoy your weekend,
 Dirk

 _________________________________________
 Dirk Schouten

 Media Action Projects
 http://utopia.knoware.nl/users/schoutdi
 Take a peek at the NEWS and REVIEWS sections!


Subject: [Announcement] bu-3.0 beta

 Date: Mon, 20 May 2002 21:14:07 -0500
 From: Vincent Stemen <bu@hightek.org>
 I have finally released bu-3.0-beta.  It has a few new FS backup
 features but most of the new features are related to CDRW dumps.  I
 have also finally put up a real web page for bu along with a lot of
 new documentation describing the new features as well as most of the
 existing features that I had not yet documented before.

 This was a larger undertaking that I had expected to have the
 capabilities I wanted.  There are over 2200 lines of new and changed
 code.  The change log and feature list show most of the details.

 The CDRW features only work on FreeBSD until I finish the Linux
 portion of the code.  If any of you are running FreeBSD, I would
 appreciate feedback on the CDRW dump features.  Linux users can still
 upgrade and use it as they have been.


Subject: Re: On BU

 Date: Mon, 27 May 2002 14:21:22 -0500
 From: Vincent Stemen <bu@hightek.org>
 On Mon, May 27, 2002 at 01:59:11PM +0200, Dirk Schouten wrote:
 > Hi Vincent,
 > Maybe I'm a bit late with my question, but here it is anyhow.
 > Will our improvement be incorporated as an option in bu's configurartion file?
 > Something like:
 > 
 > copy empty directories = yes/no
 > 
 > Bye for now,
 > dirk

 Hi Dirk.

 I was not originally planning to.  Do you need the ability to turn off
 the copying of empty directories?  If so, how would that be an
 advantage in your situation?  It would be possible to add if necessary
 with a little more coding.  I am moving this to the mailing list in
 case anybody else has any opinions to express about it.

 Also, to give you an update: The code changes are taking considerably
 more work than I had anticipated.  I have made good progress but will
 likely not be done for a few more days.  I discovered another weakness
 while testing that I am also fixing while I am at it.  I will write
 documentation to fully describe it but, briefly, there were situations
 where you would not get the correct permissions and ownerships on
 directories in the backup filesystem.  Since I want bu to mirror
 filesystems as closely as possible, I am fixing this while I am at it.
 It is actually a problem with all existing Unix tools where it comes
 to bu's ability to arbitrarily back up any file or directory whether
 the parent directories have been backed up already or not.

 Example:

 If you type "bu /home/joe/projects/foo" and /home/joe/projects did
 not already exist on the backup filesystem, the parent directories,
 /home/joe/projects get created with default ownership and
 permissions not matching those on the original filesystem.  This
 happens even if you use "cp -a", cpio, or tar.

 Vincent


Subject: Re: On BU

 Date: Thu, 30 May 2002 04:00:02 -0500
 From: Vincent Stemen <bu@hightek.org>
 On Mon, May 27, 2002 at 11:15:41PM +0200, Dirk Schouten wrote:
 > Hi Vincent,
 > Some replies from a UNIX analphabetic and a computer ignorant:
 > 
 > >I was not originally planning to.  Do you need the ability to turn off
 > >the copying of empty directories?  If so, how would that be an
 > >advantage in your situation? 
 > Vincent, I do not need turning off empty directories. I was only wondering
 > how a next version of B U would look like.
 > Would it be version x with "no backup of empty directories" and
 > version x1 with "the ability to backup empty dirs",
 > or would it be version xn with the choise of yes/no backup of empty dirs.
 > Something like the possibility to do full or incremental backups as it is
 > now in B U.

 Hi Dirk.

 The next beta release will automatically backup empty directories in
 order to duplicate the original filesystems as closely as possible.  I
 do not currently plan to make it an option to turn it off unless I or
 somebody else comes up with a significant need or reason to do so that
 I have not yet thought of.

 > For your information (and to reveal a bit on my 'simple of mindness'):
 > I do a _full_ backup every night. I do not want to remember what's the full
 > backup and what's the incremental. I am only a simple network administrator
 > on a simple primary school. I feel safe with a full backup.
 > I tell you this to inform you on on the situation of one of your users.

 I have been doing all incremental backups with bu for several years.
 I am curious why you do a _full_ backup every night (assuming you mean
 you are turning incremental off).  I'm not sure if you are fully aware
 of how bu works but incremental mode copies any file that is newer or
 does not exist on the backup filesystem.  So, the first backup will be
 a full one by default since no files have been copied yet.  The only
 situation that should cause the end result of doing incremental vs
 full to be any different is if the time setting is significantly off
 between the two machines causing the file modification times to be
 wrong on one machine or the other.  In that case you can do a full
 backup once after reseting the time then go back to incremental.

 One of the ways I use bu the most is to stay backed up throughout the
 day.  I keep it in incremental mode and sometimes run it from the
 command line as often as every few minutes.  I will do some work that
 I don't want to loose and type "bu ." from my work directory and have
 the warm fuzzy feeling of seeing the specific files I have changed get
 copied to our NFS server without having to wait for it to copy files
 unnecessarily.

 Of course, I still need to add a synchronization feature to delete old
 files from the backup filesystem that no longer exist on the source
 filesystem.  A couple of people have requested that but I have not
 been able to commit the time to do it yet.  In fact, it would probably
 even be nice for it to be smart enough to correct any changes in file
 ownerships/permissions while it is at it.  Until I do, the backup
 filesystem gradually gets dirtier and fuller than the source
 filesystem over time and eventually needs to be wiped and started
 over.

 If anybody needs this bad enough to contribute financially to the
 cause, I could also probably take time off to get that done sooner as
 well.

 Vincent


Subject: Re: On BU

 Date: Mon, 27 May 2002 23:15:41 +0200
 From: Dirk Schouten <schoutdi@knoware...>
 Hi Vincent,
 Some replies from a UNIX analphabetic and a computer ignorant:

 >I was not originally planning to.  Do you need the ability to turn off
 >the copying of empty directories?  If so, how would that be an
 >advantage in your situation? 
 Vincent, I do not need turning off empty directories. I was only wondering
 how a next version of B U would look like.
 Would it be version x with "no backup of empty directories" and
 version x1 with "the ability to backup empty dirs",
 or would it be version xn with the choise of yes/no backup of empty dirs.
 Something like the possibility to do full or incremental backups as it is
 now in B U.
 For your information (and to reveal a bit on my 'simple of mindness'):
 I do a _full_ backup every night. I do not want to remember what's the full
 backup and what's the incremental. I am only a simple network administrator
 on a simple primary school. I feel safe with a full backup.
 I tell you this to inform you on on the situation of one of your users.

 >Also, to give you an update: The code changes are taking considerably
 >more work than I had anticipated.  I have made good progress but will
 >likely not be done for a few more days. 
 We do not want you to have it ready 'tomorrow'. (But this does not mean we
 want _too_ much delay)

 > I discovered another weakness
 >while testing that I am also fixing while I am at it.  I will write
 >documentation to fully describe it but, briefly, there were situations
 >where you would not get the correct permissions and ownerships on
 >directories in the backup filesystem.  Since I want bu to mirror
 >filesystems as closely as possible, I am fixing this while I am at it.
 This I can grasp (understand) and I am glad you fix it, although I have not
 yet noticed the problem.

 >If you type "bu /home/joe/projects/foo" and /home/joe/projects did
 >not already exist on the backup filesystem, the parent directories,
 >/home/joe/projects get created with default ownership and
 >permissions not matching those on the original filesystem.  This
 >happens even if you use "cp -a", cpio, or tar.
 Ahh, I am so glad you are the expert!! I do not understand what to say.
 Keep on working and we (all the users of BU 'next version') will end up
 with something that's an improvement.

 To give you a small update on what I have been doing the last days:
 Arguiing in a Dutch newsgroup on education and new media about educational
 institutions paying for  'free' software.  In Holland there are a lot of
 schools that use 'free software' in the sense of  'free beer'. What I say
 is that we have money enough to pay developers and that we shoud, with our
 contributions, keep free software free. 
 The last couple of hours, since this remark  the topic has remained  _very_
  silent.... Bah, sometimes I despise my country-fellows and deeply
 understand what 'Dutch treat' means.

 We keep in touch,
 Dirk

 _________________________________________
 Dirk Schouten

 Media Action Projects
 http://utopia.knoware.nl/users/schoutdi
 Take a peek at the NEWS and REVIEWS sections!


Subject: Re: On BU

 Date: Thu, 30 May 2002 11:41:28 +0200
 From: Dirk Schouten <schoutdi@knoware...>
 Hi Vincent,
 LOL on your 'fuzzy warm feeling'!
 Thank you for your extensive reply on full and incremental.

 >I am curious why you do a _full_ backup every night (assuming you mean
 >you are turning incremental off). 
 That's correct.
 > I'm not sure if you are fully aware
 >of how bu works but incremental mode copies any file that is newer or
 >does not exist on the backup filesystem.  So, the first backup will be
 >a full one by default since no files have been copied yet.  
 As I understand it. Even when incremental = on , the first time you do a
 backup B U makes a full backup.

 >The only
 >situation that should cause the end result of doing incremental vs
 >full to be any different is if the time setting is significantly off
 >between the two machines causing the file modification times to be
 >wrong on one machine or the other.  In that case you can do a full
 >backup once after reseting the time then go back to incremental.
 I think I understand.
 Maybe I should tell you: I make a backup every night on a secnd HD in the
 same computer. I have 5 directories: /monday, /tuesday ... /friday.
 With cron at 04.00 am a backup is made of a couple of dirs.
 Once a week I shut off the sambaserver, insert a HD in a tray, switch on
 the server and make a backup which I store on another place, outside the
 school. 
 Maybe there are better, more elegant, less time consuming possiblilities.
 It sure gives this newbie a warm fuzzy feeling :).

 >
 >Of course, I still need to add a synchronization feature to delete old
 >files from the backup filesystem that no longer exist on the source
 >filesystem.  A couple of people have requested that but I have not
 >been able to commit the time to do it yet.  In fact, it would probably
 >even be nice for it to be smart enough to correct any changes in file
 >ownerships/permissions while it is at it.  Until I do, the backup
 >filesystem gradually gets dirtier and fuller than the source
 >filesystem over time and eventually needs to be wiped and started
 >over.
 >
 >If anybody needs this bad enough to contribute financially to the
 >cause, I could also probably take time off to get that done sooner as
 >well.
 Since this is the mailing list it is perhaps an idea to ask you how much
 such a significant improvement would cost. The readers could then say how
 much they individually  would like to contribute. Ah, how I love the
 implications of the new economy!

 Kind regards,
 dirk

 _________________________________________
 Dirk Schouten

 Media Action Projects
 http://utopia.knoware.nl/users/schoutdi
 Take a peek at the NEWS and REVIEWS sections!


Subject: Re: fuzzier feeling

 Date: Fri, 31 May 2002 16:59:58 -0500
 From: Vincent Stemen <bu@hightek.org>
 On Fri, May 31, 2002 at 03:03:09PM +0200, Afd. ICT Rosaboekdrukker wrote:
 > Hi Vincent,
 > Doing a full backup and occasionally looking at the screen, seeing _all_ the
 > files being copied passing by gives me a warmer, fuzzier feeling than an
 > incremental backup. With incremental I only see a couple of files. Is this
 > really trustworty?? :)).

 Hi Dirk.

 It has been trustworthy for me.  On the other side of the coin, I have
 caught mistakes many times using incremental because I expected only a
 few files to be copied and when a lot of files started going by,
 discovered I specified a wrong directory or was using the wrong backup
 filesystem.  Also, if I cannot remember if I made any more changes
 since I last backed up, and bu tells me "No new or changed files to
 back up", it quickly confirms to me that I am fully backed up.  This
 is the way I have used bu for years.

 Incremental mode is really nice for running from the command line on
 specific directories or files all the time throughout the day, even if
 you feel more comfortable using full mode for your nightly backups.
 In fact, this method of usage is one of the primary reasons I
 originally wrote bu.  Up to 8 or 10 hours of work can be lost in a
 crash before the scheduled nightly backup and no other tools I found
 were designed to be used in this way.

 However, that is why I made bu so configurable, so it fits the needs
 and preferences of everybody :-).

 Have a good weekend.
 Vincent


Subject: Re: Bu errors when a file type changes to or from a directory

 Date: Fri, 31 May 2002 23:07:14 -0500
 From: Vincent Stemen <bu@hightek.org>
 On Sat, Mar 23, 2002 at 01:18:29PM -0600, Vincent Stemen wrote:
 > On Sat, Mar 23, 2002 at 12:14:55PM +0100, Alain Cochard wrote:
 > > Hello.  Me again.
 > > 
 > > I had a file, say 'foofoo'.  After having changed the name of this
 > > file, I created a directory also named 'foofoo'  (to which I moved the
 > > initial 'foofoo' file, together with other new files).
 > > 
 > > At the next incremental backup, bu smartly notified me that:
 > > 
 > >    cp: `/backup/home/me/foofoo' exists but is not a directory
 > > 
 > > The problem is that the above warning (or an equivalent one) did not
 > > appear in the log file.  Only because I was standing by chance in
 > > front of the computer that I noticed it.
 > > 
 > > Is it the expected behavior?  If yes, I would be tempted to say that
 > > it is not fortunate.
 > > 
 > > I'm using version 2.8.
 > > 
 > > Best regards,
 > > Alain
 > > 
 > 
 > Hi Alian.
 > That's a good point.  The stderr of cp needs to go in the log file as
 > well.  I added it to my todo list.
 > 
 > Thanks for the input.
 > 
 > Vincent
 > 

 This was not originally posted on the list but I am following up here
 in case others have encountered it.

 This problem is now fixed in the about to be released 3.1 beta.  The
 backup() routine has been completely re-written in Perl and no longer
 uses "cp".  It uses a tar stream and utilizes part of the code I wrote
 for the CDRW dumps.  Situations similar to the one described above no
 longer generate an error.  It corrects the difference.  If a file type
 has changed between backups, for example from a directory to a regular
 file, or vice versa, bu will remove the file or directory from the
 backup filesystem first, so there should be no more errors of this
 nature.  It should always correct the backup filesystem to match the
 original filesystem.

 When there are errors, there is also now an error log, $LOG.errors.
 Although, not all errors are logged in it yet, but some are.

 Vincent