Boxcryptor very slow opening files from LibreOffice

sombra

Hi,

I work with Libreoffice. After I have updated to Libreoffice 3.6.0.4 (before I had version 3.5), I have this situation:

when I open a Libreoffice file (odt or ods) Boxcryptor needs very much CPU (about 80%) and nothing happens. After 10-20 seconds the file opens normal. The same happens if I click the file with the right mouse button for preferences. Boxcryptor needs very much CPU and "freezes" for about 10-20 seconds.

This only happens with Libreoffice files. If the files are not stored in Boxcryptor, everything runs fine.

If I open PDF-Files Boxcryptor also needs very much CPU but it dont freezes. Just if I open the document fast a second and a third time, sometimes I become a error message. But here the problem is not so urgent like with Libreoffice files.

Regards.

Robert

Hi Sombra,

Just like with the other problem, it would be great if you could provide us a debug log when the problem occurs. To create the debug file do the following:
1) Quit BoxCryptor
2) Type into the Windows startmenu "boxcryptor.exe /debug"
3) Reproduce the error
4) Quit BoxCryptor
5) The "BoxCryptor.log" is located on your desktop

Best,
Robert

sombra

Hi Robert,

I have the log-File. What should I do with it? Should I send it to you via Email or do you prefer me to load it on Dropbox?

While I do it, Windows Explorer crashes two times...

sombra

I tried to send it through your contact webpage, but the connection allways lost. Maybe because of the size of 25 mb?

What should I do? Can you tell me a email adress?

sombra

Hi Robert,

because I became no answer, I send the logfile to the email-adress info@seco***.com.

I hoppe this was correct so and I would appreciate to ear something from you.

Regards.

Robert

I received it and I will investigate it.

-- Robert

Robert

Hi sombra,

I checked your log and the problem is that LibreOffice executes many many small file read operations rather than few big read operations. Here's an excerpt of the log file:

18:44:5327 | 662160 ReadFile : \file.ott | 4606 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4607 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4608 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4609 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4610 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4611 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4612 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4613 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4614 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4615 | 512 | 512
18:44:5327 | 662160 ReadFile : \file.ott | 4616 | 512 | 512

The first line shows that LibreOffice requested to read 512 bytes beginning at byte 4606 within the file.ott. Then it requests 512 bytes beginning at byte 4607 (second line) etc. Many small reads or writes degrade BoxCryptor's performance especially when they are smaller than BoxCryptor's block size of 4 KB (4096 Bytes) because BoxCryptor always has to read and decrypt the full block, even if only 1 byte has to be read.

There's not much to help you from our side. This file read behavior seems to be a bug in LibreOffice - especially when you didn't experience it before. Strange enough, LibreOffice (3.6.0) did not show this behavior on our test computer. Here it requests bigger chunks of data and correctly increments the offset.

18:01:8868 | 1644768 ReadFile : \sample.ott | 0 | 262144 | 262144
18:01:8948 | 1644768 ReadFile : \sample.ott | 262144 | 262144 | 262144
18:01:9028 | 1644768 ReadFile : \sample.ott | 524288 | 262144 | 262144
18:01:9108 | 1644768 ReadFile : \sample.ott | 786432 | 262144 | 262144
18:01:9118 | 1644768 ReadFile : \sample.ott | 1048576 | 33152 | 33152

Best,
Robert

sombra

Thanks Robert. Really strange...

I downgraded to version 3.5.6 and now is everything OK.

Thanks.