It looks like you are trying to copy from a process other than the one which holds the lock.
Think abnout it - the lock gives exlusive access to the file to the process which sets it and blocks all other processes. Stan Bielski wrote: > Just to make sure I understood you correctly, is this what you are suggesting? > > * Open file with sqlite app (in my case sqlite3) > * execute BEGIN EXCLUSIVE TRANSACTION; > * initiate the file copy > * COMMIT; after the copy is finished. > > I tried doing this, but very early into the copy Windows issues the > following error: > > Errror 0x80070021: The process cannot access the file because another > process has locked a portion of the file. > > > On Tue, Jul 7, 2009 at 1:03 PM, John Stanton<jo...@viacognis.com> wrote: > >> You should synchronize your backup (copy). Try surrounding it with an >> exclusive transaction. >> >> Stan Bielski wrote: >> >>> Sorry for the repost, but the original thread was hijacked by another >>> list user. This is a serious problem IMHO; it looks like the DB can't >>> be backed-up without rendering the machine unusable if a query hits it >>> while a copy is in progress. >>> >>> Hello, >>> >>> In the course of copying a largish (20 GB) database file while >>> accessing it via sqlite3, the machine became very unresponsive. I >>> opened task manager and found that the system was using a huge amount >>> of virtual memory, causing it to thrash. Per-process memory usage >>> looked normal and did not add up to anywhere near system-wide VM >>> usage. >>> >>> I ran into this issue at a customer site and was able to reproduce it >>> using a local Windows 2008 installation. I have not installed any >>> backup software or a virus scanner. Storage is local disk, SQLite >>> version is 3.3.17. >>> >>> At first I thought that this was a general Windows problem involving a >>> process accessing a file that is being copied, but other binaries I >>> tested do not cause the same behavior that sqlite3 does. I performed >>> the following experiments to try to diagnose the issue. >>> >>> Case 1: >>> >>> * I copy a 20 GB sqlite DB using Windows' own copy utility (e.g. via >>> explorer). >>> * At any point during the copy, I open the file being copied in sqlite3 >>> * I exit sqlite3. >>> * During the rest of the copy the OS will consume virtual memory >>> linear (seemingly identical) to the amount of data copied since the >>> process opened the file. >>> >>> I repeated this experiment using a similarly-sized file created from >>> /dev/zero (i.e. an invalid DB) and the results were the same. >>> >>> Case 2: >>> >>> * I copy the sqlite DB using Windows' own copy utility (e.g. via explorer). >>> * At any point during the copy, I run 'strings' with the file as an >>> argument. >>> * I exit strings. >>> * The copy does not result in the OS consuming additional virtual memory. >>> >>> Case 3: >>> >>> * I open the DB in sqlite3 >>> * I let sqlite3 idle and do not input any commands. >>> * I copy a sqlite DB using Windows' own copy utility (e.g. via explorer). >>> * I continue to let sqlite3 idle and do not input any commands. >>> * During the rest of the copy the OS will consume virtual memory >>> linear (seemingly identical) to the amount of data copied since the >>> process opened the file. >>> >>> Is there a workaround for this issue? Any assistance or info is appreciated. >>> >>> Thanks, >>> -Stan >>> _______________________________________________ >>> sqlite-users mailing list >>> sqlite-users@sqlite.org >>> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >>> >>> >> _______________________________________________ >> sqlite-users mailing list >> sqlite-users@sqlite.org >> http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users >> >> > _______________________________________________ > sqlite-users mailing list > sqlite-users@sqlite.org > http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users > _______________________________________________ sqlite-users mailing list sqlite-users@sqlite.org http://sqlite.org:8080/cgi-bin/mailman/listinfo/sqlite-users
