Akeeba Backup for Joomla!

Thursday, 10 January 2013 04:22 CST

user67358

Mandatory information about my setup:

Have I read the related troubleshooter articles above before posting (which pages?)? Yes
Have I searched the tickets before posting? Yes
Have I read the documentation before posting (which pages?)? Yes
Joomla! version: 2.5.8
PHP version: 5.3.13
MySQL version: 5.1.57
Host: Dedicated server running Windows 2008 R2, IIS and MySQL
Akeeba Backup version: 3.6.12 (same problem with 3.6.8)

EXTREMELY IMPORTANT: Please attach a ZIP file containing your Akeeba Backup log file in order for us to help you with any backup or restoration issue. If the file is over 2Mb, please upload it on your server and post a link to it.

Description of my issue:

When I create a backup in Zip format with multi-part zip file, the resulting file set cannot be opened in WinZip. WinZip gives error "Error: unable to seek to begining of central directory." I'm checking the Zip file on a local drive on the server so it's not a post-processing issue, all the parts of the Zip file seem to be there (.z01, z02, .zip).

Turning off the split archieves function results in a big zip file that can be opened by WinZip, but they the post process to upload to Azure fails.

How can I create a multi-part/split Zip file that can be opened?

Thursday, 10 January 2013 04:26 CST

nicholas

Akeeba Backup's ZIP feature follows precisely the ZIP standard (a.k.a. APPNOTE.txt) as provided by PKware. I have verified that the split archives do open correctly when using PKZIP for Windows which is the reference implementation of the ZIP format by the company which invented and still maintains the official ZIP format. If you do not want to spend money on PKZIP for Windows –understandably, it's an expensive piece of software– you can always use our free Akeeba eXtract Wizard which is available for Windows, Linux and Mac OS X. It is designed to extract single- and multi-part archives generated by Akeeba Backup, be it ZIP, JPA or JPS.

Nicholas K. Dionysopoulos

Lead Developer and Director

🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!

Thursday, 10 January 2013 04:40 CST

user67358

Thanks for your fast reply.

I just tested the split Zip file with Akeeba eXtract Wizard and it gives the error:

"The central directory is missing records; your archive appears to be truncated and can't be extracted"

I get the same message on many different files when loading the file on the web server itself. So I would say the problem is somewhere in the creation of the multi-part zip files and not in the software used to open them. I've tried different settings for the split size but no difference.

What do I do to get this working for future backups?

Thursday, 10 January 2013 05:13 CST

user67358

Also, given this is a public ticket is there any chance that you can remove my email address from under the profile photo? I can't edit my username in my profile. Yes I caused this by using an email address as the username but who wants to remember usernames anyway.

Anyway can you remove the email before every spammer in the world adds me to their medical supplies list?

Edited by user67358 on 2013-01-10 05:18 CST

Thursday, 10 January 2013 10:32 CST

nicholas

IMPORTANT: I have now changed your login name to gsimonds. You may have to reenter your Download ID to all of your Akeeba Backup Professional installations.

Sorry for the late reply. I have to go through the ZIP implementation in Akeeba Backup, its generated archives and archives generated by PKZIP and WinZIP with a hex editor to see what's going on. I found the problem. At the end of the ZIP file we are supposed to write the End of Central Directory Record which we do. One of the fields of this record is called "offset of start of central directory with respect to the starting disk number". The obvious meaning is that this is an offset relative to the start of the archive ("starting disk" is elsewhere meant to be "first archive part"). Yes, that would be the logical conclusion, but not what the spec means. They actually mean "relative to the first disk (archive part) where the central directory is located in". That's a huge difference.

So, to the practical side of things now.

You can extract your existing backup archives using Kickstart. You will not be able to extract them with anything else.

In order to address this issue I made a small change in the ZIP engine of Akeeba Backup. You can find it in the latest developer's release. I would appreciate it if you could install it and test the resulting backup archive.

Nicholas K. Dionysopoulos

Lead Developer and Director

🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!

Thursday, 10 January 2013 21:49 CST

user67358

Thanks for your explanation and software update.

I installed the latest developers release and created a multi-part zip backup which was uploaded to Azure.

I'm happy to say that I can now open the multi-part zip files in WinZip. Thanks for the update and email change.

Friday, 11 January 2013 02:30 CST

nicholas

Awesome! Thank you very much for your feedback!

Nicholas K. Dionysopoulos

Lead Developer and Director

🇬🇷Greek: native 🇬🇧English: excellent 🇫🇷French: basic • 🕐 My time zone is Europe / Athens
Please keep in mind my timezone and cultural differences when reading my replies. Thank you!

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