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<p>Hi Jonathan -</p>
<p>Thanks for the "heads-up" regarding wal files. The technical
problem is using the xFAT file system - when xFAT gets corrupted,
it will partly be write-protected. This will inhibit QGIS in
making the 2 wal files (or updating or deleting them). <br>
</p>
<p>But QGIS has an issue here: When the situation occurs, QGIS will
quietly tell you about in the relatively obscure log system. And
it will show you an <b>empty</b> GeoPackage - no layers. That is
not smart. It will upset users (It certainly did upset me :-) .
They will believe, that their precious layers in the GeoPackage
has disappeared. However, the layers is perfectly alright. If you
copy the GeoPackage to another filesystem, QGIS will happily open
the layers from the copy. <br>
</p>
<p>IMHO, a better approach would to have a big fat error message
informing users that they have a problem with the underlying file
system. (I plan to write a feature request about this later today)
<br>
</p>
<div class="moz-cite-prefix">
<p> <br>
</p>
--
<pre class="moz-signature" cols="72">Med venlig hilsen / Kind regards
Bo Victor Thomsen
</pre>
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<div class="moz-cite-prefix"><br>
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<div class="moz-cite-prefix">Den 18-05-2020 kl. 17:49 skrev Jonathan
Moules:<br>
</div>
<blockquote type="cite"
cite="mid:34908334-89b9-ab21-c6b4-2be63394db3a@lightpear.com">
<meta http-equiv="Content-Type" content="text/html; charset=UTF-8">
<p>Hi Bo,</p>
<p>Looking at the WAL docs for SQLite (<a
class="moz-txt-link-freetext"
href="https://www.sqlite.org/wal.html" moz-do-not-send="true">https://www.sqlite.org/wal.html</a>)
(what geopackage is built from) I see this:</p>
<p>"The WAL file exists for as long as any database connection has
the database open. Usually, the WAL file is deleted
automatically when the last connection to the database closes.
However, if the last process to have the database open exits
without cleanly shutting down the database connection, or if the
SQLITE_FCNTL_PERSIST_WAL file control is used, then the WAL file
might be retained on disk after all connections to the database
have been closed."</p>
<p>So it sounds like whatever the last process is to touch the
GeoPackage may not be closing the connection cleanly on exFat.</p>
<p>Cheers,</p>
<p>Jonathan<br>
</p>
<div class="moz-cite-prefix">On 2020-05-11 13:10, Bo Victor
Thomsen wrote:<br>
</div>
<blockquote type="cite"
cite="mid:dff03255-2f20-d875-5474-15485b099714@gmail.com">
<p>Hi all -</p>
<p>I have a strange problem. I'm have 3 different disk on my
windows based system on Mac hardware<br>
</p>
<ol>
<li>My system drive. Formatted to NTFS.</li>
<li>A flash-drive. Formatted to FAT32.</li>
<li>A data drive. Formatted to exFAT. The last is my primary
data drive and is shared between my Windows partition and my
Mac partition on my MacBook Pro. Hence the use of exFAT.<br>
</li>
</ol>
<p>I have a QGIS plugin, which copies a template of a GeoPackage
file to "where-ever the user wants it placed" and afterward
make some content changes in the copy using the PyQT QSQL
module with the QSPATIALITE driver<br>
</p>
<p>This work if the Geopackage file is copied to either disk no
1 (NTFS) or disk no 2 (FAT32). However, it doesn't work if the
file is copied to disk no 3 (exFAT). The process leaves the
WAL files even after the database is closed properly. <br>
</p>
<p>And even more strange: If I reformat the flash-drive to exFAT
and repeat the experiment using the reformatted drive it too
works without a hitch.</p>
<p>The normal "divide et impera" method tells me that my exFat
data disk is bork'ed. However this error <b>only</b> occurs
with the QGIS/GeoPackage creation/modification scenario.
Everything else is working OK.<br>
</p>
<p>The disk is not shared on the network. Has anyone experienced
the same type of problems ? And have a solution ?? Just asking
before I begin to clean up / reformat my 100 GB data disk <br>
</p>
<p>System setup: MacBook Pro 2014 / Windows 8.1 OS /QGIS 3.10.5
(the same problem occurs with 3.10.0 , 3.10.2 ...3.12.2) <br>
</p>
<br>
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<pre class="moz-signature" cols="72">--
Med venlig hilsen / Kind regards
Bo Victor Thomsen
</pre>
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