After a fresh install of Owncloud you may get the following error after uploading a file larger than a couple of MB.
“Failed to Write to Disk”
This is a pretty quick and easy one to fix, it is just a setting in the php.ini file, for example on Gentoo
Then we have to uncomment and set the “upload_tmp_dir” to a logical location for Owncloud, on our test machine we set it to the following.
upload_tmp_dir = /var/www/localhost/htdocs/owncloud/data/tmp
While you are here you may also want to increase the “upload_max_filesize” as that could cause some problems with big files. We set ours to 1GB but you could do what you feel comfortable with.
upload_max_filesize = 1024M
Once you have saved the php.ini make sure that you create your tmp directory if it does not already exist
mkdir /var/www/localhost/htdocs/owncloud/data/tmp ; chown -R apache:apache /var/www/localhost/htdocs/owncloud/data/tmp
Now restart apache and you should be all set.