Not sure if this rings a bell for any of you, but I can always give it a try.
I created a backup program based upon DotNetZip. This allows me a.o. to create AES 256 password protected zips.
Two recent full backups (zips of 40 GB) did not open correctly in a program like 7-Zip. I see only the first directory and then the first file of it. A test of the zip says
ERRORS: Headers Error Unconfirmed start of archive
WARNINGS: There are data after the end of archive
With a couple of more tests I found:
1 It is (now) always (reproducible) creating the zip again with the same selection (and probably a few more files)
2 Windows Explorer sees all directories (but can't open file because it does not support AES 256)
3 Winzip also can open everything the same zip
4 After creating some parts of the original backup the problem remained only in file from which I further found:
- It is not the size (one of the other 'partly' backups is 4x larger
- It does not seem to be the content either): one separate backup with only the root of that disk and one with only the subdirs with content resulted in 2 readable backups (=all the same files of the non working combined backup)
- When I create the same backup as differentials (so on the 'problem' disk the same root + subdirs but less files) this zip also opens in all programs.
So there does not seem to be a logical reason nor a solution. Maybe Fabrice has an idea (as X# FabZip uses DotNetZip too)?
Dick
DotNetZip created backup sometimes causes issues in (only) some unzip programs
DotNetZip created backup sometimes causes issues in (only) some unzip programs
Hi Dick,
unfortunately, I have not idea...
Have you tried with the same set of files (same condition), without AES ? or with another encryption method ?
just a shoot in the dark...
Fab
unfortunately, I have not idea...
Have you tried with the same set of files (same condition), without AES ? or with another encryption method ?
just a shoot in the dark...
Fab
XSharp Development Team
fabrice(at)xsharp.eu
fabrice(at)xsharp.eu
DotNetZip created backup sometimes causes issues in (only) some unzip programs
Hello Fabrice,
I should have added that to the list of what I tried. The problem is the same regardless the use of password protection.
Thanks for your suggestion though.
Hopefully I get an idea soon....
Dick
I should have added that to the list of what I tried. The problem is the same regardless the use of password protection.
Thanks for your suggestion though.
Hopefully I get an idea soon....
Dick
DotNetZip created backup sometimes causes issues in (only) some unzip programs
Hi Dick,
So ... Could it be related to the name of the Zipped files ?
Special Names, Special chars or char that are not/badly supported ??
Fab
So ... Could it be related to the name of the Zipped files ?
Special Names, Special chars or char that are not/badly supported ??
Fab
XSharp Development Team
fabrice(at)xsharp.eu
fabrice(at)xsharp.eu
DotNetZip created backup sometimes causes issues in (only) some unzip programs
Hello Fabrice,
The strange thing is that if I split the faulty content in 1 zip with the root content and one zip with the content fo all subdirectories, both zips are problem free. This while having the same content as the 1 zip file with both.
And it can't be the size either, because 1 of the other 'partly' zip files is 4 times bigger.
I also try to find some logic, so far in vain. There must be something which is written into the zip file in this specific combination which causes some zip programs to stop reading more than the first directory/file while others (like Explorer) still see the correct content in the same file. But what...
Dick
Dick
The strange thing is that if I split the faulty content in 1 zip with the root content and one zip with the content fo all subdirectories, both zips are problem free. This while having the same content as the 1 zip file with both.
And it can't be the size either, because 1 of the other 'partly' zip files is 4 times bigger.
I also try to find some logic, so far in vain. There must be something which is written into the zip file in this specific combination which causes some zip programs to stop reading more than the first directory/file while others (like Explorer) still see the correct content in the same file. But what...
Dick
Dick
DotNetZip created backup sometimes causes issues in (only) some unzip programs
Hi Dick,
this indeed rings a bell to me. Can you show us the code you are using to create the zip?
Regards
Meinhard
this indeed rings a bell to me. Can you show us the code you are using to create the zip?
Regards
Meinhard
- ArneOrtlinghaus
- Posts: 407
- Joined: Tue Nov 10, 2015 7:48 am
- Location: Italy
DotNetZip created backup sometimes causes issues in (only) some unzip programs
The original old ZIP-File formats had limits on the file sizes of single files and on the file size of the zipped file of 4 GB. Perhaps it is this the reason?
Arne
Arne
DotNetZip created backup sometimes causes issues in (only) some unzip programs
Hello Meinhard,
It's actually a C# program and I think this is basically what I do. First I assign List<FileInfo> liFilesToBackup to which files to be zipped are added from an XML file.
collect. Then I call:
This method then goes through the List, I stripped anything which I think is irrelevant, like checks on files dates or attributes like differentials, progress info and logs:
The CreateZipEntry as called within that loop looks as follows, again the important code.
Is there anything you may see which is missing or wrong?
Dick
I would be great if a simple addition would do the trick!Meinhard post=26318 userid=300 wrote: this indeed rings a bell to me. Can you show us the code you are using to create the zip?
It's actually a C# program and I think this is basically what I do. First I assign List<FileInfo> liFilesToBackup to which files to be zipped are added from an XML file.
collect. Then I call:
Code: Select all
DoZipping(cZipName,FileMode.Open,liFilesToBackup,dLastChanged,lDifferential,lIncremental);
Code: Select all
try
{
using (Ionic.Zip.ZipFile zip = new Ionic.Zip.ZipFile())
{
string cPW = this.PW.Password.ToString();
if (!string.IsNullOrEmpty(cPW))
{
if (this.pkzip.IsChecked == true)
{
zip.Encryption = Ionic.Zip.EncryptionAlgorithm.PkzipWeak;
}
if (this.aes128.IsChecked == true)
{
zip.Encryption = Ionic.Zip.EncryptionAlgorithm.WinZipAes128;
}
if (this.aes256.IsChecked == true)
{
zip.Encryption = Ionic.Zip.EncryptionAlgorithm.WinZipAes256;
}
zip.Password = cPW;
}
zip.ZipErrorAction=ZipErrorAction.Skip;
zip.UseZip64WhenSaving = Zip64Option.AsNecessary;
string cFilesToBackup = liFilesToBackup.Count.ToString();
tStart = DateTime.Now;
foreach (FileInfo file in liFilesToBackup)
{
cFileFull = file.FullName;
bool lResult = CreateZipEntry(zip, file, cFileFull);
} // ForEach
try
{
zip.SaveProgress += ZipSaveProgress;
zip.Save(cZipName);
} // try
catch (Exception e)
{
}
} // using
} // try
catch (System.Exception e)
{
}
Is there anything you may see which is missing or wrong?
Code: Select all
private bool CreateZipEntry(Ionic.Zip.ZipFile zip, FileInfo file, string cFileFull)
{
{
string cFileToBackup;
string cPath;
string cFileOnly;
string cRoot;
string cPathOnly;
int nLen;
try
{
DateTime dtNow = File.GetLastWriteTime(cFileFull);
cPath = System.IO.Path.GetDirectoryName(cFileFull);
cFileOnly = System.IO.Path.GetFileName(cFileFull);
cFileToBackup = cPath + "" + cFileOnly;
cRoot = System.IO.Path.GetPathRoot(cFileFull);
nLen = cRoot.Length;
cPathOnly = cPath.Remove(0, nLen - 1);
cFileToBackup = cPathOnly + "" + cFileOnly;
if (cFileToBackup.Substring(0, 1) == "")
cFileToBackup = cFileToBackup.Substring(1);
System.Text.StringBuilder builder = new System.Text.StringBuilder(cFileToBackup);
builder.Replace("", "/");
string cPathToAdd = builder.ToString();
try
{
{
var zipEntry=zip.AddFile(cFileFull, cPath);
zipEntry.Comment=cPath.Substring(0,1);
}
if (lResetArchivebit)
{
bool lArchive = ((File.GetAttributes(cFileFull) & FileAttributes.Archive) == FileAttributes.Archive);
File.SetAttributes(cFileFull, File.GetAttributes(cFileFull) & ~FileAttributes.Archive);
}
}
catch (Exception e)
{
}
return true;
} // try mainloop
catch (Exception e)
{
}
};
// return taskZip1File.Result;
}
DotNetZip created backup sometimes causes issues in (only) some unzip programs
Hello Arne,
Dick
No, that is not the problem. A full backup, over 4 different (logical) disks is 42 GB. When I create a separate backup for each of the disks, the one with the error is <6GB while one other without problems is 25 GB.ArneOrtlinghaus post=26319 userid=367 wrote:The original old ZIP-File formats had limits on the file sizes of single files and on the file size of the zipped file of 4 GB. Perhaps it is this the reason?
Dick
- ArneOrtlinghaus
- Posts: 407
- Joined: Tue Nov 10, 2015 7:48 am
- Location: Italy
DotNetZip created backup sometimes causes issues in (only) some unzip programs
if Only 7-zip does not manage to read the zips then perhaps 7-zip is the problem. 7-zip surely has reprogrammed the zip-format and does not use another DLL.
Otherwise perhaps some files/directories are changing while trying to zip the files? The bigger the list of files to save the bigger gets this risk.
Or what is not excluded: Interaction with other tasks on the same computer, for example an Antivirus.
Arne
Otherwise perhaps some files/directories are changing while trying to zip the files? The bigger the list of files to save the bigger gets this risk.
Or what is not excluded: Interaction with other tasks on the same computer, for example an Antivirus.
Arne