Calibre Network Request

[erwin1234]

Originally Posted by Adoby

Also, if/when calibre really becomes multiuser, then that implies that the problems with access over the network has been solved. Perhaps the two are not directly related, but multiuser support necessitate network access.

Yes the problem will be solved when the multiuser calibre is ready!

You do not have to solve the network file access problem, it will just not be needed anymore. I can imagine that Kovid wants to avoid network file access competely and use a database driven approach. So all data is going over the network using database requests, the client connects to the database on the server transparantly, only the calibre server manipulates the files, locally, on the server. You could even connect over the internet this way and add and manipulate books and metadata.

So until there is a multiuser networked calibre, my single user library-on-network-share issue is still relevant

[cybmole]

maybe you need to see what cached-write settings windows is using on the networked drives. Your issues may go away if you disbale all write caching - just a thought.
by default AFAIK windows sets removable drive to don't cache, fixed drives to cache - not sure what it does with network mapped drives...
As what works for others is not working for you, and you all have the same calibre software, it is likely that windows file management settings are the differentiating factor.

[CRussel]

One thing to check if you're trying to use Calibre across a network share. Make sure that you have mapped the drive from both your user logon and elevated. I do this from each of two command line windows, one regular and one as administrator. (The windows I use are actually PowerShell, but a cmd window will be the same for this.) Type:

 Net use K: \\server\share

At each cmd window, where server and share are replaced by the win7 computer and the share name. And you can use whatever drive letter you want, but K: seemed right to me.

Something that Calibre is doing seems to need that administrative connection.

[shaqan]

you might kill your "calibre library" while accessing it from several devices at once. It's using SqLite and SqLite is single-user database. Multiple accesses may very easily corrupt the whole thing.

[mundus08]

I got the „OSError: [Errno 13] Permission denied“ after made a software update on my Synology DS211 NAS. Before calibre worked perfect for years in my single user environment.
I debugged the source code and found these lines in filenames.py:
# try:
# windows_hardlink(path, dest)
# return
# except:
# pass
…

def windows_hardlink(src, dest):
import win32file, pywintypes
try:
win32file.CreateHardLink(dest, src)
except pywintypes.error as e:
msg = u'Creating hardlink from %s to %s failed: %%s' % (src, dest)
raise Exception(msg % e)
src_size = os.path.getsize(src)
# We open and close dest, to ensure its directory entry is updated
# see http://blogs.msdn.com/b/oldnewthing/.../10251026.aspx
for i in range(10):
# If we are on a network filesystem, we have to wait for some indeterminate time, since
# network file systems are the best thing since sliced bread
try:
if windows_get_size(dest) == src_size:
return
except EnvironmentError:
pass
time.sleep(0.3)

For me it’s a bit weird to use a hardlink on a linux/samba based fileserver. I downloaded the calibre source from http://calibre-ebook.com/get-involved and switched to development mode as described in http://manual.calibre-ebook.com/develop.html. I commented out windows_hardlink call. Calibre 2 now works perfect again without any errors when importing or moving books.

[itimpi]

Calibre is not officially supported with the library on a network server. If it works then OK, but if you have problems with the library on a network device then you are on your own.

[Agama]

Why not use your own simple locking system via a .bat file script? Choose a shared location for your lock file and only launch calibre if the lock file does not exist. On return to the script when calibre closes you then delete the lock file. Then make each user a shortcut to this script in place of the normal calibre shortcut so that they don't run calibre outside of the locking.

This should work as an interim solution although the .bat file will stay open whilst calibre is running and locking could be circumvented by a rogue user deleting the lock file.

[erwin1234]

Originally Posted by itimpi

Calibre is not officially supported with the library on a network server. If it works then OK, but if you have problems with the library on a network device then you are on your own.

Yes we know itimpi, kovidgoyal left this thread with a clear message that he does not want to be bothered about this, more than a year ago. See the first page. So yes, we are on our own for quite a while already

Originally Posted by mundus08

I got the „OSError: [Errno 13] Permission denied“ after made a software update on my Synology DS211 NAS. Before calibre worked perfect for years in my single user environment.
I debugged the source code and found these lines in filenames.py:
.....
For me it’s a bit weird to use a hardlink on a linux/samba based fileserver. I downloaded the calibre source from http://calibre-ebook.com/get-involved and switched to development mode as described in http://manual.calibre-ebook.com/develop.html. I commented out windows_hardlink call. Calibre 2 now works perfect again without any errors when importing or moving books.

Nice catch. The hardlink should ofcourse also fail on a windows (CIFS/SAMBA) server since hardlinking only works within a local filesystem. Will try this solution!

[erwin1234]

Originally Posted by Agama

Why not use your own simple locking system via a .bat file script? ....

I suggested this last year see earlier messages but it is not a solution, the root cause of the error lies elsewhere. Calibre has a problem with a networked filesystem. Although some users have reported success: please read this thread.

[erwin1234]

Wow 6,517 views as of today! Kovid are you sure you do not want to come back?

[eschwartz]

Originally Posted by erwin1234

Wow 6,517 views as of today! Kovid are you sure you do not want to come back?

And how many of those views are just from people wanting to know what all the fuss is about? Or suggesting the use of rsync instead?

Kovid will be ready when he's ready.

[BetterRed]

Originally Posted by erwin1234

Nice catch. The hardlink should ofcourse also fail on a windows (CIFS/SAMBA) server since hardlinking only works within a local filesystem. Will try this solution!

@erwin1234 - Suggestion : do a search for "remote Hardlinks" here Link Shell Extension

Not sure if its relevant, but I have found the author of LSE, Herman Shinagl, to be most forthcoming in providing knowledge on obscure issues - e.g. how to get real symbolic links on XP/NTFS.

Disclosure : I made a minor contribution to LSE's early development.

BR

[Adoby]

Originally Posted by erwin1234

I suggested this last year see earlier messages but it is not a solution, the root cause of the error lies elsewhere. Calibre has a problem with a networked filesystem. Although some users have reported success: please read this thread.

No, calibre is not designed to work with networked filesystems. Indeed you are instructed not to store the calibre library on a networked filesystem, because it most likely won't work. So it could be argued that networked filesystems have a problem with calibre.

Calibre makes assumptions about the filesystem that are only guaranteed to be true on a local filesystem. And even that may fail if that local filesystem is shared or the files in the calibre library are accessed by other programs while calibre is running.

Sometimes accepting reality means adapting. If you don't duck when you try to enter a house with a low doorway, you may end up with severe damage to your head or structural damage to the house.

Some day in the future the house may get a bigger doorway, but until then please duck if you want to enter.

[eschwartz]

I wonder if it is also calibre that has problems with Google Drive (renames files out from under you) or with having files simultaneously open in other programs like MSWord or synced by Dropbox/other.