User manual QUANTUM A-SERIES FTP FILE SERVER 07-2008

[. . . ] A-Series FTP File Server A-Series FTP File Server 81-81800-03 A01 Quantum A-Series FTP File Server User's Guide, 81-81800-03 A01, July 2008. Quantum Corporation provides this publication "as is" without warranty of any kind, either express or implied, including but not limited to the implied warranties of merchantability or fitness for a particular purpose. Quantum Corporation may revise this publication from time to time without notice. COPYRIGHT STATEMENT Copyright 2008 by Quantum Corporation. [. . . ] This is automatically detected and accommodated by A-Series drives as with all other GbE products. Gigabit Ethernet is backwards compatible so you can connect an A-Series drive to 100Base or even 10Base networks although your transfer speed will be much slower than even these networks can accommodate since the drive must stop each time it runs out of data and then restart when it gets the next packets. The Jumbo Frames setting is discussed in the configuration sections but is worth mentioning here. It allows transfers of much larger packets and most GbE devices can accommodate them (for instance, all MacPro computers have dual Jumbo Frame enabled GbE ports). Enabling Jumbo Frames provides about a 25% increase in performance in our experience. You will have to experiment in your environment, but it should be worth trying. When Directory Updates Occur 2 It is important for users to understand that the directory (also known as the TOC or Table of Contents) is only updated when the user fully disconnects from the drive. Thus, if you wrote something to the tape and then turned off the drive before disconnecting, that information will 57 Quantum A-Series FTP File Server User's Guide Chapter 2 Using the FTP File Server A-Series Best Practices never be recorded in the TOC and the archived data has no record of being written and is at that point lost. You will see a power failure message and data loss warning when you reconnect and it may be possible for Quantum to recover that data, but this is clearly a situation to avoid. For this reason we not only recommend that A-Series drives be on an uninterruptible power supply (UPS), and also that users always select the Disconnect button whenever an archiving session is completed. Further, to be completely safe, the tape should always be ejected from the drive when done. This is most easily done from the Contextual menu (right click in the tape directory column) and select Eject Tape for standalone drives or Prepare for magazine unload on SuperLoaders. File Naming Considerations 2 FTP Servers and Clients typically do not handle many unusual characters such as quotation marks or slashes, and some can't handle even minor infractions such as extra spaces or periods. A-Series version 3. 0 and later firmware has been modified to accept any filenames within our 97 total character limit, regardless of special characters, as we have seen many user problems arising from this. With this new capability to accommodate any filename in place, there will be still be issues when users attempt to restore such files cross platform. When a Mac file has characters illegal on a Windows machine, and you attempt to restore it to a Windows machine, the transfer will fail because Windows will not let the application create that file name. In general, it is best practice to limit your filenames to be absolutely safe and adhere to the Windows filename restrictions: · No control characters (Carriage Return (CR), NULL, and Linefeed (LF) are control characters) · Don't use < > : " / \ | ?* % · Don't use space or period as the last character If you are not adhering to this limited recommended naming practice, the only way to be assured files will restore is to put them back on the same type of machine they came from. Note that, to the best of our knowledge, any Windows files can still always be restored to Macs because Windows naming is much more restrictive. Quantum A-Series FTP File Server User's Guide 58 Chapter 2 Using the FTP File Server A-Series Best Practices Third-Party FTP Clients 2 While A-Series drives employ the IT industry FTP standard, use of the A-Series with other FTP clients may cause problems for a variety of reasons: · Many FTP clients we have evaluated cannot be set for a long enough timeout to handle latencies experienced with tape drives and especially with SuperLoader operations · While A-Series drives use standard FTP commands, they also support extended FTP SITE commands which are not supported by third-party FTP clients (like eject, erase, etc. ) · Error messages important to understanding any problems which may be encountered are frequently not passed on to the user by thirdparty FTP clients · Extended drive capabilities such as viewing MXF properties or doing partial restores can not be accessed by third party FTP clients For these reasons, we strongly recommend that the A-Series only be accessed by our built-in Web-served FTP client or approved third-party applications (currently including only the Pictron Network Tape Gateway application and Imagine Products HDLog / TEP applications). One more set of reasons to be cautious of general purpose FTP clients is that most do not support Apple file resource forks as described in the following section. Users who want to use third-party FTP clients may still be able to do so without problems, especially on Windows platforms. Many customers have reported good results with Flash FXP in that environment. Please note that in those situations where you are doing so, Quantum cannot offer technical support. Apple Resource Forks and the A-Series 2 Apple computers before Mac OSX used something called "resource forks" to keep track of what application created each file rather than the Windows convention of a three letter dot suffix to keep track of the association (i. e. a . doc file is a Microsoft Word file or a . jpg is a JPEG image). [. . . ] SNTP is based on NTP, the Network Time Protocol, an industry standard way for computers to synchronize their time to an external reference standard. Each consists of a client, for example the SuperLoader, which obtains the current time (in UTC) from either an SNTP server or an NTP one. SNTP and NTP are in wide use on the Internet. reread from the disk or corrected by ECC. [. . . ]