Troubleshooting

The ExpeDat applications may report diagnostic messages if an unusual or aberrant condition occurs.  If the software does not appear to be working as expected, please re-read the documentation, including the "Known Issues" section and the list below.  If the performance is not as expected, be sure to read the performance chapter.  You may also find useful tips amongst the DEI Tech Notes.

If you are unable to resolve a problem, submit a Technical Support Request or email support@DataExpedition.com.

When reporting trouble, describe the circumstances as fully as possible.  Include the exact text of any messages and the revision codes of the applications.  The GUI version can be found by clicking the "Help" or Options Opt button.  Version codes in the CLI versions are displayed by adding "–v" to the command line.  Information about your networking environment, such as link type and speed, operating systems, and types of files being transferred is also very helpful.  See Tech Note 0037 for advice on achieving the fastest resolution to your request.

Following are some circumstances and diagnostic messages which you may encounter when using ExpeDat:

Data transfer speed is less than expected

Performance is always limited to the slowest component of any data path.  This includes storage, network links, routers, and every other device from a file's source to its destination.  There may be steps you can take to remove or work around such limitations.  Carefully read the Performance chapter for information on evaluating and optimizing your data path.

If you are copying a folder containing a large number of small files, try enabling Streaming Folders.  See the ExpeDat Desktop or movedat sections on folder copying for details.

MTP collects detailed diagnostic information about network and storage systems during each transaction.  See Tech Note 0033 for instructions on how to collect this data and send it to DEI for analysis.

Clicking an expedat:// URL results in an error or nothing happens

Either ExpeDat Desktop is not present, it was moved, or it was deleted.  See the Clients for Web Integration chapter for instructions.

The license period for this software has expired

You are using a trial or temporary executable and the time limit has expired.  You must download an updated version from either the DEI website or your customer download site.  See Tech Note 0012 for tips on updating your software, particularly if you are getting this error after installing purchased software.

Local Network: No Application at Given Port

This most likely means that the server is not currently running on the machine indicated by the server address or port.  Check that you have entered the correct address and port into the client.  If the server is running on a private network that is different from the client's network, you must make sure that the server's router has Network Address Translation (NAT) correctly configured.  Also check that the client is using the public address of the router, not the private address of the server.

No communication from the server for a while. Still Trying...

This warning occurs when there has been no communication from the server for several seconds.  The current transaction is still active and the client is still trying to reach the server.  If the transaction is able to resume, you may see a message such as "Server communication restored".  If the server remains inaccessible, the current transaction will fail as described below.  In either case, you should investigate your network for connectivity problems.

Local Network: No Response

This indicates a connectivity problem.  Verify that you are using the correct server address and port number.  Check the network connectivity between the two systems and make sure that an ExpeDat server is running on the remote system.

If there is a firewall or NAT device in the path, make sure that it is configured to pass through the UDP port number of the server.  For ExpeDat, the default server port is UDP 8080.  See DEI Tech Note 0002 for detailed instructions on configuring firewalls.

If the server you are contacting hosts multiple IP addresses, try using its default address (usually the first one listed by "ifconfig -a" or "ipconfig /all").  Note that servedat can be configured to bind to a specific local address by using the "-n" option or Interface configuration variable.

Bad Credentials, Username, or Password
Invalid username or password

You have not provided a valid username and password as required by the server.  Verify that you are contacting the correct server and that you have correctly typed the username and password.  See the Users chapter for details of how servedat matches usernames and passwords.  For a new server installation, see the Adding Users chapter for step-by-step authentication setup instructions.

Waiting for storage
Waiting for Server
Data transfer seems to pause at the end of a long transfer.

ExpeDat does not consider a file transfer complete until all of the data is written to storage.  Some other applications claim to be done while your data is still cached in memory.  If you frequently receive "Waiting" warnings, you may need to investigate your storage device or adjust your system write caching policies.  See Write Confirmation for details.

I cannot find my files on the server

If the client does not specify a remote path, then the server will determine a Home Directory based on the username provided (if any) and the server's configuration options.  Carefully read the Home Directories chapter for details.

Request Denied: User restricted to home directory

Absolute pathnames (those starting with "/", "C:/", or similar) are not permitted for Anonymous users, users with RestrictHome enabled, or when the global RestrictHome option is enabled, or when running without authentication enabled.  The AllowPath option can be used to create specific exceptions to this restriction.

The license code is not accepted or not remembered

Non-expiring versions of the software may require that you enter a license code the first time you run the software on new hardware.  If a computer has multiple network interfaces, such as ethernet and WiFi, the license code may need to be re-entered the first time you switch between interfaces.  You must enter the specific license code that matches the software and hardware you are using.  For more information about license codes, see the Setup chapter.  For more license code error messages and their possible meanings, see Tech Note 0027.

Unable to resolve host

The Domain Name or IP address could not be understood.  Verify that you are using the correct name and that your system is online.

Object Busy: Try again later

The file you are attempting to access is being used by another transaction or application.  If it is being uploaded by another ExpeDat transaction, you may receive an estimate of when it is expected to complete.

Server Busy
Server Capacity Exceeded: Try again later

The server may be beyond its configured capacity.  Wait for auto-retry or try your transaction again later.  If the problem persists, contact the server administrator.

FileWrite WARNING: Filesystem took XXms to write XX bytes
Write took XXms for XX bytes
File close took XX ms

These warnings occurs when a file write operation takes longer than 1000ms to complete.  It indicates that the network is delivering data faster than storage can keep up.  This may occur with network attached storage when transferring data at high speeds, on operating systems with excessive write cache sizes, when writing to slow media such as a USB stick, or when any storage system is in heavy use.  For example, anti-virus software which tries to scan files while data is still being written can cause such performance problems.

This warning may be safely ignored if it occurs only occasionally and performance is acceptable.  Frequent occurrence of this warning, especially with very high I/O latency, may indicate a serious hardware problem.  See Tech Notes 0018 Raid Performance, 0029 Tuning Network Attached Storage, and 0035 Linux Performance Tuning for storage optimization suggestions.

FileRead WARNING: Filesystem took XXms to read XX bytes

This warning occurs when a file read operation takes longer than 1000ms to complete.  It may occur when reading from an excessively busy storage system.  It may also indicate a serious problem with the storage media.  If the warning occurs frequently with long I/O times and poor performance, check the host operating system and storage devices for I/O or media errors.

Clock skipped XX seconds: performance may be impaired

These messages occur when an MTP application has been suspended from execution for longer than 200ms while trying to transfer data.  This can happen on systems with overloaded CPUs, particularly virtual machines on busy hosts.  It can also happen on systems configured to emphasize power saving over performance.

If the messages only occur occasionally and performance is acceptable, they can be safely ignored.  Frequent occurrences accompanied by poor transfer speeds indicate a problem with the operating environment.  Check the host operating system and hardware for performance limitations.  See Tech Notes 0023 Recommended Hardware, 0025 Amazon Web Services, and 0035 Linux Performance Tuning for system optimization suggestions.

Handler failed (system 10): No child processes

On some Linux systems, after installing or updating servedat, object handlers may begin failing with this message.  This is caused by bugs in some versions of systemd, resulting in servedat being launched without process group rights.  Rebooting the Linux system will fix the problem.

Other "MTP0" "DOC0" or "SEQ0" messages are appearing

These messages are produced if MTP encounters very unusual conditions or errors.  If you are unable to resolve the issue based on the message output and the problem persists, please contact technical support for assistance.