Real Time or Continuous Backup Software?
Thread Starter
Joined: Nov 2002
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From: 39N 77W
Real Time or Continuous Backup Software?
Real Time or Continuous Backup Software?
A friend has asked me the following question. Can any of you help?
seacue
---- quoting ----
Is there a backup utility that starts by creating a full partition
image on an (external?) drive and then keeps its backups up-to-date
by continually backing up files as they are changed? There would be
a default list of file types subject to these backups, editable by
user. Or maybe an exclusion list of file types NOT to back up. I'd want
a user interface that seamlessly integrated the partition images
and the later file-level backups. That way, if you needed to
restore a file that you had accidentally trashed or had become
corrupted, you wouldn't have to think about where you'd
find the latest intact version - in the partition image or in
later file backups. There would be issues of having multiple file
versions, but that's something that authors of file-backup
software have found ways of dealing with.
Shutting down the PC without disabling continual backups means
there is a high probability of interrupting a write operation to
the target drive. One should have a scheme to allow shutdown
without corrupting the contents of the drive used for the backups.
A friend has asked me the following question. Can any of you help?
seacue
---- quoting ----
Is there a backup utility that starts by creating a full partition
image on an (external?) drive and then keeps its backups up-to-date
by continually backing up files as they are changed? There would be
a default list of file types subject to these backups, editable by
user. Or maybe an exclusion list of file types NOT to back up. I'd want
a user interface that seamlessly integrated the partition images
and the later file-level backups. That way, if you needed to
restore a file that you had accidentally trashed or had become
corrupted, you wouldn't have to think about where you'd
find the latest intact version - in the partition image or in
later file backups. There would be issues of having multiple file
versions, but that's something that authors of file-backup
software have found ways of dealing with.
Shutting down the PC without disabling continual backups means
there is a high probability of interrupting a write operation to
the target drive. One should have a scheme to allow shutdown
without corrupting the contents of the drive used for the backups.
Administrator
Joined: Mar 2001
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From: Twickenham, home of rugby
Acronis gets the popular vote.
But try googling for "imaging backup software" or "drive image backup software"
Then read through the software specs to see if all the requirements are met.
SD
But try googling for "imaging backup software" or "drive image backup software"
Then read through the software specs to see if all the requirements are met.
SD
Joined: Dec 1999
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From: Where?
Thread Starter
Joined: Nov 2002
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From: 39N 77W
No, a RAID array doesn't keep earlier versions which are increments from the last major backup. A RAID array is a way of reducing exposure to HD disk failure, but doesn't allow going back to (slightly) earlier versions of files.
Plastic PPRuNer
Joined: Sep 2000
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From: Rochechouart, France
Another vote for MirrorFolder
DeltaCopy - http://www.aboutmyip.com/AboutMyXApp/DeltaCopy.jsp - is a Windows wrapper for rsync - fast and free.
DeltaCopy - http://www.aboutmyip.com/AboutMyXApp/DeltaCopy.jsp - is a Windows wrapper for rsync - fast and free.
Joined: Feb 2007
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From: Dublin, Ireland. (No, I just live here.)
There is a commercial product I've worked with, NSI DoubleTake, which is used on servers. After an initial Mirror, it switches to a Replication mode that immediately copies any changes over = near real-time, depending on how fast the network is. You can define filters on what to replicate, and control bandwidth and schedules. However, it's not really "backup", because if there's any damage on the source (e.g. you delete a file)... it replicates the damage too. Unless you limit transmission times, that happens Immediately. 
You don't say what version of Windows your friend has, but if it's Vista, he has the Shadow Copy option built-in. This is a "snapshot" technology adapted from Windows Server 2003, that "copies out" modified data blocks to a new location quickly and transparently. What you get is a friendly "Previous Versions" tab on a directory or file's Properties that lets you roll back changes, which sounds like it fits the bill. However, without going into too much detail about snapshots, note that it copies only the disk blocks that change, not whole files or directories, so it relies on the original drive being up: it's useful, but it's not a full replacement for backup to an external location.
What about the standard Windows Backup program? Select the external drive as the target, Advanced mode in the Wizard, set up the schedule you want, and use Incremental mode to back up only changed files.
Heck, if your friend wants to get back to basics, use XCOPY /S with /M or /A (using the file Archive bits).
You don't say what version of Windows your friend has, but if it's Vista, he has the Shadow Copy option built-in. This is a "snapshot" technology adapted from Windows Server 2003, that "copies out" modified data blocks to a new location quickly and transparently. What you get is a friendly "Previous Versions" tab on a directory or file's Properties that lets you roll back changes, which sounds like it fits the bill. However, without going into too much detail about snapshots, note that it copies only the disk blocks that change, not whole files or directories, so it relies on the original drive being up: it's useful, but it's not a full replacement for backup to an external location.
What about the standard Windows Backup program? Select the external drive as the target, Advanced mode in the Wizard, set up the schedule you want, and use Incremental mode to back up only changed files.
Heck, if your friend wants to get back to basics, use XCOPY /S with /M or /A (using the file Archive bits).
More bang for your buck
Joined: Nov 2005
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From: land of the clanger
No, a RAID array doesn't keep earlier versions which are increments from the last major backup. A RAID array is a way of reducing exposure to HD disk failure, but doesn't allow going back to (slightly) earlier versions of files.
There would be issues of having multiple file versions, but that's something that authors of file-backup software have found ways of dealing with.
Administrator
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From: Twickenham, home of rugby
Ideally you would use a snapshot-aware NAS - such as a NetApp filer. I remember having a presentation from and discussion with them about 6 years ago, and I was extremely impressed with their concept.
From their white paper:
Interestingly, they use RAID 4 in their filers - the dedicated parity disk avoids having to overwrite data blocks with parity data, thus maximising the space available for data and shadow copies.
SD
From their white paper:
Files are composed of blocks, which are linked together to form files. Each block pertaining to a file contains bits of information that are part of the file. File systems keep track of the information stored in blocks.
WAFLŪ is write-optimized and always writes new disk blocks to available locations on disk. Pre-existing data blocks are never overwritten. This is true whether a new file is being created or an existing file is being updated. This process minimizes disk drive seeks, which improves performance. Thus preexisting blocks still exist and can be accessed in the form of Snapshot copies until they are deleted. The amount of disk space reserved for such copies is configurable on a per-volume basis.
Snapshots are not copies of data, rather Snapshots record the state of the blocks in the file system at a given point in time and provide read-only access to that image of the file system.
WAFLŪ is write-optimized and always writes new disk blocks to available locations on disk. Pre-existing data blocks are never overwritten. This is true whether a new file is being created or an existing file is being updated. This process minimizes disk drive seeks, which improves performance. Thus preexisting blocks still exist and can be accessed in the form of Snapshot copies until they are deleted. The amount of disk space reserved for such copies is configurable on a per-volume basis.
Snapshots are not copies of data, rather Snapshots record the state of the blocks in the file system at a given point in time and provide read-only access to that image of the file system.
SD
Plastic PPRuNer
Joined: Sep 2000
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From: Rochechouart, France
"...get back to basics, use XCOPY /S with /M or..."
XXCOPY - http://www.xxcopy.com/index.htm - is far more powerful, has none of XCOPY's inconsistent behaviour and is free for non-commercial use.
XXCOPY - http://www.xxcopy.com/index.htm - is far more powerful, has none of XCOPY's inconsistent behaviour and is free for non-commercial use.
Joined: Dec 2000
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From: United Kingdom
Wait a few more weeks and Microsoft Windows Home Server will be available(the product has just been released to manufacturing) and OEM's will be selling their versions of the servers before the end of the year.
It will do exactly what you asking and as it was designed from the start as a home user product very easy to set up.
If it is for business use, then really you need to invest in Windows Server 2003 and a decent backup system (hardware & software)!
Also here is a video on Home server being demonstrated.
It will do exactly what you asking and as it was designed from the start as a home user product very easy to set up.
If it is for business use, then really you need to invest in Windows Server 2003 and a decent backup system (hardware & software)!
Also here is a video on Home server being demonstrated.
