Providing online data backup and restore, disaster recovery, and business continuity services

  

Data Processing & DS-Client Backup Appliance

Is data held on the DS-Client Backup Appliance or does it pass straight through? The DS-Client Backup Appliance acts as a gateway only, passing data through after it has been compressed and encrypted, using delta blocking, common file elimination and a digital signature. A database showing information on what has been backed up is held on the DS-Client Backup Appliance, but no actual data files are retained.    Is the Database on the DS-Client Backup Appliance backed up? Yes, by default the DS-Client Backup Appliance backs its own database up at 6:00am every morning, although this time can be changed if desired.    What happens if too much data is passed to the DS-Client Backup Appliance? The DS-Client Backup Appliance only requests data as it can process it and will not pull more data across the network than can be processed.    What is common file elimination? Common file elimination is one of the sophisticated ways that the DS-Client Backup Appliance reduces the raw data from your network servers to a size that can be transmitted over the leased line. It ensures that the same data is never transmitted offsite more than twice, thereby saving the bandwidth to transmit only new, unique data. It achieves this simple elimination by generating a Checksum of each file as it is backed up and comparing it against the known details of all previous files. If the Checksum matches a previously backed up file, it must be a duplicate and only a shortcut need be transmitted up the line.    Due to the way this technique is applied, it does not matter if the files are on different servers, or even have different filenames - the DS-Client Backup Appliance will still only transmit two copies.    What happens if a server stops or crashes during backup or if the backup is interrupted for some other reason? If the backup is stopped, for whatever reason, it will simply continue onto the next backup in its schedule. It will not revisit the failed backup set until the next time it is set to run, e.g. the following night, at which point it will pick up where it left off. If however the problem has been rectified, and backup window allows, the backup can be restarted manually, immediately. DataAssure has a dedicated team who monitor the progress of backup events 24 hours a day. If a problem occurs, it will be escalated through the appropriate channels.    Does the DS-Client Backup Appliance hold a connection open to a server all the time? No, the DS-Client Backup Appliance will only connect to your servers during the specified backup schedule, therefore will not use valuable connection licence at other times.    How many versions of my backed up files are held off site? By default, 7 versions of each backup are held. Unlike a tape backup, where the routine is to rotate tapes in a cycle, DASB will only backup a new version of a file when it has changed, guaranteeing that the customer is not wasting space backing up exactly the same version more than once. For example, if a file only changes once a month, we will have 7 months worth of that file. The number of versions stored can be configured on an individual backup set basis. Each backup set can be configured down to include just one file if desired, giving you the ability to maximize the efficiency of the storage.    What platforms are supported? DASB has full agentless support for a range of network platforms.    "NetWare 3 facilities include the ability to backup the bindery, where NetWare 4 and 5 include support for NDS.    "Windows NT & W2K is fully supported. Basic workstations and servers can have the registry backed up, where more advanced environments will take advantage of being able to backup MS SQL and Exchange, without the need to stop the service or install an agent. DASB provides full support to backup workstations operating Windows 95/98 and its registry.    Can the software backup Permissions on files? Yes, for Windows NT on NTFS volumes DASB can backup both Permissions and Streams. The Permissions and Extended NetWare Attributes can be backed up for NetWare. This is a configurable option in both NetWare and NT environments.    If the software is agentless, how is MS SQL and Exchange backed up? Microsoft® developed SQL and Exchange with the backup requirement in mind. Both products can respond to API calls requesting the services to dump their data, whilst online, to an external destination. In DASB's case the product simply asks the specified MS SQL or Exchange server to stream the data to the DS-Client Backup Appliance where it is delta blocked and transmitted offsite. This process is a totally supported Microsoft function and guarantees compatibility with your existing MS systems. This adhesion to Microsoft standards does however prevent us from restoring individual Exchange mailboxes as this is not a function Microsoft has ever supported.    Can DASB run pre and post commands on servers? Yes, even though DASB is an agentless solution, it is still capable of running commands on remote servers, be it NetWare or NT. For example, shutting down a database or application running on a server to back it up correctly and restart afterwards, or perhaps interact with some overnight batch processing.    How does DASB handle open files? Open files are an issue in most backup environments. If a file is open exclusively on a workstation, it is the server's responsibility to stop anyone else, including a backup package, accessing that file.    To help counteract these issues DASB has a range of options which attempt to handle open files. These options, combined with use of the Pre and Post commands, should enable the backup of almost any file. More complex environments such as Oracle or Sybase can usually be configured to dump their data into a normal file which will be delta blocked and backed up as normal.