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  • lcm337
  • (4 posts)

If a scheduled backup cant run (ie computer switched off) is it set to run as soon as it can?

Does the scheduled backup check a file to decide whether to upload? What are these checks? (file date/size or md5 checksum etc)

Are these same checks used for real time backups?

Thanks!


9/12/2007 2:56:26 AM

  • DriveHQ Webmaster
  • (1099 posts)
Subject: Re: scheduled backups

>> If a scheduled backup cant run (ie computer switched off) is it set to run as soon as it can?

Yes. It is. Please make sure you have the latest version Online Backup build 248.

>> Does the scheduled backup check a file to decide whether to upload? What are these checks? (file date/size or md5 checksum etc)

All of these are checked to determine if the file needs to be uploaded again. Even if the physical file has not been changed in the case of "MagicCode" match, the file date on server is still updated but upload is skipped.

>> Are these same checks used for real time backups?

All DriveHQ Client software (FileManager, Desktop Express, Online Backup) uses the same advanced caching, date-time comparison and MagicCode comparison. MagicCode is a proprietary version of MD5 and is generally much more secure than MD5.


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9/12/2007 4:41:58 AM

  • lcm337
  • (4 posts)
Subject: Re: Re: scheduled backups

User: DriveHQ Webmaster  -  9/12/2007 4:41:58 AM

>> If a scheduled backup cant run (ie computer switched off) is it set to run as soon as it can?

Yes. It is. Please make sure you have the latest version Online Backup build 248.

>> Does the scheduled backup check a file to decide whether to upload? What are these checks? (file date/size or md5 checksum etc)

All of these are checked to determine if the file needs to be uploaded again. Even if the physical file has not been changed in the case of "MagicCode" match, the file date on server is still updated but upload is skipped.

>> Are these same checks used for real time backups?

All DriveHQ Client software (FileManager, Desktop Express, Online Backup) uses the same advanced caching, date-time comparison and MagicCode comparison. MagicCode is a proprietary version of MD5 and is generally much more secure than MD5.

Thanks for the answers!

I have a problem in that I have a TrueCrypt file (encrypted mounted drive) that doesnt change size or change its date when you write to the drive (a fixed size file is allocated on creation) and I'm guessing MagicCode isnt picking up the changes so the latest file isnt being backed up.

Have you come accross this before? Is there anything I can do to ensure its backed up?


Reply
9/13/2007 3:13:12 AM

  • DriveHQ Webmaster
  • (1099 posts)
Subject: Re: Re: Re: scheduled backups

User: lcm337  -  9/13/2007 3:13:12 AM

User: DriveHQ Webmaster  -  9/12/2007 4:41:58 AM

>> If a scheduled backup cant run (ie computer switched off) is it set to run as soon as it can?

Yes. It is. Please make sure you have the latest version Online Backup build 248.

>> Does the scheduled backup check a file to decide whether to upload? What are these checks? (file date/size or md5 checksum etc)

All of these are checked to determine if the file needs to be uploaded again. Even if the physical file has not been changed in the case of "MagicCode" match, the file date on server is still updated but upload is skipped.

>> Are these same checks used for real time backups?

All DriveHQ Client software (FileManager, Desktop Express, Online Backup) uses the same advanced caching, date-time comparison and MagicCode comparison. MagicCode is a proprietary version of MD5 and is generally much more secure than MD5.

Thanks for the answers!

I have a problem in that I have a TrueCrypt file (encrypted mounted drive) that doesnt change size or change its date when you write to the drive (a fixed size file is allocated on creation) and I'm guessing MagicCode isnt picking up the changes so the latest file isnt being backed up.

Have you come accross this before? Is there anything I can do to ensure its backed up?

Well, I believe our backup program checks the file time and file size before it re-computes the MagicCode. If the file time and size never changes, it will assume the file has not been updated. I am surprised that TrueCrypt doesn't update file size and file date... It seems we need to do some tweak on this. Please also check if you can configure it so that it changes the file time.


Reply
9/13/2007 11:13:16 AM

  • lcm337
  • (4 posts)
Subject: Re: Re: Re: Re: scheduled backups

User: DriveHQ Webmaster  -  9/13/2007 11:13:16 AM

User: lcm337  -  9/13/2007 3:13:12 AM

User: DriveHQ Webmaster  -  9/12/2007 4:41:58 AM

>> If a scheduled backup cant run (ie computer switched off) is it set to run as soon as it can?

Yes. It is. Please make sure you have the latest version Online Backup build 248.

>> Does the scheduled backup check a file to decide whether to upload? What are these checks? (file date/size or md5 checksum etc)

All of these are checked to determine if the file needs to be uploaded again. Even if the physical file has not been changed in the case of "MagicCode" match, the file date on server is still updated but upload is skipped.

>> Are these same checks used for real time backups?

All DriveHQ Client software (FileManager, Desktop Express, Online Backup) uses the same advanced caching, date-time comparison and MagicCode comparison. MagicCode is a proprietary version of MD5 and is generally much more secure than MD5.

Thanks for the answers!

I have a problem in that I have a TrueCrypt file (encrypted mounted drive) that doesnt change size or change its date when you write to the drive (a fixed size file is allocated on creation) and I'm guessing MagicCode isnt picking up the changes so the latest file isnt being backed up.

Have you come accross this before? Is there anything I can do to ensure its backed up?

Well, I believe our backup program checks the file time and file size before it re-computes the MagicCode. If the file time and size never changes, it will assume the file has not been updated. I am surprised that TrueCrypt doesn't update file size and file date... It seems we need to do some tweak on this. Please also check if you can configure it so that it changes the file time.

Hi, Okay you can make truecrypt change the file modification date on modifications. Although this does limit the functionality of the program. ("plausible deniability" of modification). (Goto Truecrypt preferences uncheck "preserve timestamps") The accessed date does change when the drive is mounted - maybe this gives you an easy tweak to make to catch truecrypt mods. Although this could of course mean transfers are made (of what are reasonable large files as they're mounted drives) when no data has changed (ie the file's been mounted to retrieve data only). Maybe one for a configuration option & documentation. Or perhaps regular forced backups for some files could be allowed. Thanks PS I've tried this and it seems to work although I'm concerned the file modification timestamp isnt enough to push the upload (ie can magiccode overrule if it finds no changes?)

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10/2/2007 2:54:25 AM

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