© Copyright Robert Vasvari, 2005-2009.
AASYNC ONLINE FAQ (Windows Version)
This FAQ is updated on a daily basis, so check back often!
I'm syncing one of my folders to a UNIX box and the sync fails, I get many failure messages.. why?I'm setting up a new sync for my website, the destination (my published website) is not empty. Right now the sync mode is set to auto (the default). Which sync mode should I use?
Is AASync free software?
Are there any situations where use of AASync is not recommended?
If AASync terminates abnormally for any reason, can it possibly damage the source or the target folder?
Remote-to-Local sync using FTP is not detecting file changes every time. Why?
Can AASync be used as a system backup?
I set up a new sync definition. The initial sync took longer than expected, so in the middle of the sync operation another automated local sync operation changed the composition of the source folder. What can I do in this situation?
Can a sync operation be safely restarted after any kind of abnormal termination?
The sync engine chokes on my web pages when I upload to the server. Why?
Can AASync handle a sync from a SAMBA mounted disk?
Does AASync have a limitation on the length or encoding of filenames?
I have a sync where the one of the folders is mounted over VPN. AASync generates a lot of network traffic. Can I reduce that somehow?
I'm syncing one of my folders to a UNIX box and the sync fails, I get many failure messages.. why?
Depending on the files you sync and the protocol you use there
are a large variety of errors you can get during the sync, especially
the first time. Different systems have various levels of tolerance
of certain filenames, character encodings, etc.. Windows has certain rules
in filenames, what characters you can and canot have. These rules are different
on other hosts, so you MUST keep in mind that syncing between different hosts
means that you must keep your filenames to adhere to the rules on BOTH sides.
Not to mention the character encoding.. if if the local and remote system uses
different encoding, the chances of errors are very high. Please read the troubleshooting
page for more answers.
If you get errors, you should repeat the sync several times. If you keep getting
failures always at a certain place, well, you may have to leave that
folder out of the sync or try to change the source, or, if all fails
and you cannot see what the incompatibility is, contact support with
the error message, transcript, etc...
I'm setting up a new sync for my website, the destination (my published website) is not empty. Right now the sync mode is set to auto (the default). Which sync mode should I use?
When a new sync definition is set up, the baseline condition needs to be reached, which means that source and destination are mostly in sync, needing only small changes. This can be achieved by running the "Source-Destination Comparison" mode. Once the sync completes in this mode, the two sides are in sync, switch to "auto" mode so the source database can be built. Once that completes stay in auto mode, your sync will be very fast since it will no longer need to scan the remote destination to find changes. See Sync Options for details on sync modes.
Is AASync free software?
Yes, and No. The Local-to-Local sync is free, but the sync ops involving remote hosts will require a license.
Are there any situations where use of AASync is not recommended?
Yes, in cases where the source could change while the sync operation is in progress. AASync keeps running while it finds changes, and terminates only when it cannot find any changes. In these cases AASync may either runs forever, or returns with an error.
If AASync terminates abnormally for any reason, can it possibly damage the source or the target folder? First off, the source folder's contents are NOT TOUCHED by AASync, so there is no chance that the source files could be damaged by AASync. Upon abnormal termination, the target folder may be in an undetermined state. Re-running AASync can solve this problem.
Remote-to-Local sync using FTP is not detecting file changes every time. Why? FTP is a very poor protocol, and does not allow an error free
comparison of files, due to the fact that FTP servers trash mod dates during upload, and allow no checksums. Due to these limitations, RtL sync
in this case may not work correctly in some cases. With most FTP servers,
mod date and size changes can be detected. One must test these servers before
productions use, to make sure sync ops work as expected.
Can AASync be used as a system backup? NO! AASync is *generic* backup program designed to be used on user folders, regular files, folders, links etc..
System folders (like /WINNT or /WINDOWS) contain special files that cannot be copied or moved. To do a system dump, one needs
a special system backup program designed for that specific purpose.
I set up a new sync definition. The initial sync took longer than expected, so in the middle of the sync operation another automated local sync operation changed the composition of the source folder. What can I do in this situation?
This situation must always be avoided! You should not set up scheduled sync for very large source folders until you are certain that the destination folder has an identical copy and the manual sync process finishes without making any changes. Only after that you can have an idea how long the sync lasts, since that is size and network speed dependent!
Can a sync operation be safely restarted after any kind of abnormal termination?
Do not have to worry about restarting at all, AASync was designed to work fine after restarts. It might spews some errors during the first restart, but as long as it has a successful run, it restores the database. Just keep on running it until it has a successful pass without any changes.
The sync engine chokes on my web pages when I upload to the server. Why? Many times web page designed programs publish your pages with : and ! characters in the filenames. When you try to upload these to an FTP server, it fails because these characters are not allowed in the filenames on most FTP servers. Solution: be sure to edit the filenames and make sure these characters are not used in the names (contents can have anything). Can AASync handle a sync from a SAMBA mounted disk? AASync does not care how you mount a filesystem onto your local host. As long as it is available to read, AAsync can use it as a source for synchronization. If it is mounted read/write, then AASync can use it as a sync destination, regardless of the underlying protocol. Does AASync have a limitation on the length or encoding of filenames? No, AASync does no impose any limitations whatsoever. That having said, the destination host/file system's limitations do apply. For instance, if you sync onto an FTP host, you cannot have characters like '@' in the filenames. I have a sync where the one of the folders is mounted over VPN. AASync generates a lot of network traffic. Can I reduce that somehow? Consider the following: In that sync AASync sees a source and destination, both of which are local folders. AASync cannot know that one of those is actually mounted over a network, that even if it has decent speed, it still is an order of magnitude slower than an internal disk. Now, the default setting in AASync for File Contents Verification (checksum in other words) is ON, so in this case AASync computes a checksum for all the files in the mounted folder, which means reading through the files. That in turn causes the VPN (or other mounts like Webdav, Samba, etc..) to actually download the file into a local cache and then serve them out like a local file. So, the solution here is to turn File Contents Verification off for this sync. AASync will rely on other metadata to detect changes of your files, and things will still work. To get the necessary metadata (like size and modification dates, etc..) should generate a lot less network traffic.