Error during opening 7z file created using Multi Commander.

[kamil_w]

I have created a 7z archive of virtual machine using Multi Commander. File has about 3GB. Archiving went well, but now, when I want to open that file using MC a window with error message appears with information "Failed to open volume. Corrupted or wrong format". I haven't got such problem with small files.

[Mathias (Author)]

I'm not able to reproduce that.
That error happen when MC can't open the file because the 7z engine does not recognize it or something.
There might be more info in the logwindow (Ctrl+L)
MC do not encode/decode 7z by it self it is using the 7za.dll that is provided by the creators of 7z
Maybe the archive was created with a newer version of 7z and then opened with a older version? or it maybe it was corrupted when copied between machines or AntiVirus is blocking MC from opening it. Or they are permission issue on the file and MC is not allowed to open it.

[kamil_w]

There might be more info in the logwindow (Ctrl+L)

I have tried one more time. There is no information about compressing, but there is an error which is appearing when archive is being opened.

Code: [Select]

2015-11-08 20:27:21.552 ERROR : Failed to open volume : "H:\BackUP\SDPWWKVMHV1.7z" - Wolumin jest zły. Uszkodzony lub nieprawidłowy format! (Error code :41)
Here is screenshot with error message:

Maybe the archive was created with a newer version of 7z and then opened with a older version? or it maybe it was corrupted when copied between machines or AntiVirus is blocking MC from opening it. Or they are permission issue on the file and MC is not allowed to open it.

1. Archive creation and opening was made in the same session of MC, so library version must be the same.
2. File wasn't copied/moved.
3. Permissions are fine.

[Mathias (Author)]

I don't know why it does not work for you. I can pack/unpack a vm images that is over 20Gig with no issues.

As I said that error is shown if the 7zip that MC is built with can't open the archive (Or if something external is preventing it like AV or other )
Why it does not work on your machine don't know.

Are you sure the 7z archive is correct ? can the standalone 7z open and unpack it ? Maybe the issues is with packing and not unpacking ?

[kamil_w]

Are you sure the 7z archive is correct ?

That is the point. 7z archive created in MC is incorrect.



EDIT:
I have installed 7zip. Is there a way to compress files using standalone 7zip by pressing key combination in MC?

[Mathias (Author)]

Then it is not unpack that is the issues but pack (all posts before was about unpacking and browsing so assumed the issues was that), however that is even more strange.
No one else seems to have that issues. So not sure why it does not work on your machine.

And as I said MC is using a dll provided by 7z to create the archive.  MC is not creating the archive by it self.
I have no idea left why it does not work on your system.  The question is really what is different from your system and other users system where it works.

The only why I can think of this happening is if something goes bad during packing, So that the packing is not completed. Did you check if there was any errors in the log windows from the packing process? MC should have shown an error dialog, But there might be some issue that made it not do that.
Maybe some of the files that it was about to pack was in use or something.

And no, external packers are not supported.  You can script it your self using the script editor.

[Timon]

May be it's a good idea to update 7z Standalone Plugin from version 9.20, that is used in MC currently?

Of course, you can say, that current 7-Zip 15.11 is only beta, but look how many problems were solved since version 9.20 was released.

History of changes in 7-Zip - http://7-zip.org/history.txt

[Mathias (Author)]

You can not compare the 7Z Api with the entire 7Zip app. the entier 7Zip app have a lot more then just 7z
Most of the things in the list is for the App and not the API
But yes upgrading is on my list. but it require to much work at the moment since they changed some apis.
And according to 7Z everything is compatible.

Also the version number of 7zip jumped from 9 to 15 ( There have not been a lot of version since 9, so 9 is not 6 version old)

The error kamil_w has, has nothing to this with this.

[Timon]

Also the version number of 7zip jumped from 9 to 15 ( There have not been a lot of version since 9, so 9 is not 6 version old)

Yes, you are right, but I never counted something only according major version builds, but between version 9.20 and 15.11 there were 18 updates released... And if you open discussion for every build, you'll see how many changes is beyond the words 'Some bugs were fixed'

[Mathias (Author)]

Yes there are bugs fixed, However most of them are for the entire 7Z app. that include zip and rar , UI and everything
Not many bugs are fixed for 7Z encoder/decode. However, It will be updated, I got it on my list.  But since I do not have a reproducible case that shows that there are issues in 7z,  an upgrade is not top prio at the moment, since doing a upgrade will eat up a lot of dev time and my time to spend on development is a bit limited.  So I have to choose, fix a known issues that can cause serious problem or upgrade something that works and have no known serious issues ?

[Timon]

Exclusively for information: 7-Zip 15.12 stable release was published just 2 hours ago.

[Mathias (Author)]

Nice.. hopefully I got some time over so I can upgrade.

[bushi]

Hello Mathias,

For what its worth, I am able to replicate something resembling this error - although I use 7Zip itself (not MC) to compress, but I am getting this error, when:
1. Create 7Zip archive (large ones, >several hundred megs - couple gigs)
2. Copy it TO a network drive (using MC - but that one goes properly; read on)
3. Copy it FROM the network drive, using MC (this might be the root cause - the FIRST copy operation FROM the network drive)
4. Try to open the file copied in 3., either by MC, or 7Zip  - got the "File corrupted" error
5. Copy the same archive FROM the network drive AGAIN (using MC, OVERWRITE the file copied in 3.) - after that, archive can be opened properly, both in MC, and 7Zip

So it looks like something dodgy happens in the FIRST copy operation FROM the network drive (since the same file, can be eventually opened, then it must be copied properly TO the network drive, and the second copy operation FROM the network, apparently, solves it)

Hope that helps.

Many thanks for your outstanding work on MC,

Regards,
Michal

[Mathias (Author)]

That is weird, then the first copy should be bad, without any error happen. I find that unlikely, unless there are bad blocks or bad memory.
But then you would see a lot of other bad files. Something else must have a hold on the file or something.
Latest release will output more errors in the logwindow. Maybe there is a error message there ?

So when the first copied are done, are the files the same size ?
Select the files in source and and target panel and select Menu>Tools>CheckSum>Compare Two files
and it will do a checksum compare on them and tell you if the content of them are different.

When you copied a archive, many AntiVirus software will take a hold on the file and check the archive before any program may use it.
And if the archive are large this can take some times. And when the files is copied a second time then it already have the hash of that file it's databas where it say it is okey. and is not doing a check that time ..  Maybe this is happening ?

[bushi]

(...) many AntiVirus software will take a hold on the file and check the archive before any program may use it.
And if the archive are large this can take some times.(...)

...ahhh, brilliant, well spotted... let me check this, but that smells like the real cause, thanks! That would explain why the network drive must be involved - company policies/antivir settings!

[Jungle]

One more problem. If you pack a folder with locked file, operation completes successfully, but archive is broken. File operations log contains fail record, but if logs are disabled you will not see that something was wrong.

One of the way to reproduce:

Code: [Select]

1. Hide MC logs
2. Create a folder and copy some files there
3. Copy e.g. *.xls file in that folder
4. Open that *.xls file in Excel
5. Try to 7z-pack the folder