PHYLOCK or VSS in Image for Windows?

Trying to pull the threads together here to answer my original question.

It would seem that VSS must take the least time to initiate a backup, but risks a complete failure to achieve a lock. IFW can accommodate that by using phylock instead, but only when VSS fails to obtain a lock.

Phylock alone on the other hand seems to need individual tuning of it's lock delays to always ensure a sensible lock time.

My opinion then, would tend be to always use both locking mechanisms, with VSS as default and failure defaulting to phylock. I would also not use the file VSS exclude checkboxes in the interests of complete backup.

If the two checkboxes for excluding pagefile.sys and hiberfil.sys ('omit' checkboxes not in the standard settings screen) work independently of which lock is achieved and when the registration key for VSS is not used, that would be the ideal position. I would like that confirmed by Terabyte.

Anybody disagree ?

 

GB, I agree... but pls don't lose sight of what I think is a major consideration.

Because of the way that VSS works, all major database applications tie in to the VSS sync feature, the feature that allows VSS to signal those apps to flush their data caches and close the database file for consistency purposes... this only happens under VSS. This feature insures that dynamic databases are "in tact" and consistent when backed up under VSS.

No such sync feature exists using PHYLOCK... only the ability to try and wait for a quiescent system before issuing the lock. If the system is quiet and the lock is issued, any open databases may not be consistent at the time of backup.

If that feature isn't a driving force... go for it!

 

In IFW I find myself confused as to why a VSS and a PHYLOCK backup are so different, when I try to use identical settings.

For VSS I do not set the 'exclude files to not backup' nor 'exclude files to not snapshot' switches, but I do set the 'omit pagefile.sys' and 'omit hiberfil.sys' switches.
For PHYLOCK I just unset the 'Use VSS when available' switch. There is no other change.

However, an image taken with VSS is 20.817 Gb and says it backed up 68035120 sectors. Immediately repeating the same backup with PHYLOCK gives an image 16.596 Gb backing up 51725328 sectors.

The only logic I can make of that is the VSS option DOES include pagefile and hibernate file (because the exclude switch is off). It is therefore IGNORING the separate omit switches which it seems are only observed by a PHYLOCK backup.

Right or wrong?

 

gbhall,

Strange. I've found VSS images to be smaller than PHYLock images.

 

I'm sorry, that is right. I mistook which image I took first in this test. Here is the log ending -

[19/09/2013 12:26:10] Image for Windows 2.82a (GUI)
[19/09/2013 12:26:10] Starting using phylock...
imagew.exe /b /d:w0@0x2 /f:"F:\IFW-Win7-012" /vb /comp:14 /desc:"using phylock"
[19/09/2013 12:26:10] PHYLock is waiting for drive writing to stop ...
[19/09/2013 12:26:13] PHYLock using drive C:
[19/09/2013 12:26:13] PHYLock Started
[19/09/2013 12:26:13] PHYLock Using Disk
[19/09/2013 12:26:13] PHYLock version 10
[19/09/2013 12:26:14] Backup: Drive 0 (C Windows7 Partition (02) 124446 MiB HPFS/NTFS
[19/09/2013 12:26:14] To: F:\IFW-Win7-012.TBI
[19/09/2013 12:36:30] INFO: Total Sectors:254865232 Total Allocated:78121136
[19/09/2013 12:36:30] INFO: 68035120 Sector(s) backed up
[19/09/2013 12:36:30] Validating: Windows7 Partition (02) 124446 MiB HPFS/NTFS
[19/09/2013 12:36:30] From: F:\IFW-Win7-012.TBI
[19/09/2013 12:51:21] Operation Completed with Error Code 0
[19/09/2013 12:51:21] Stop
--------------------------------------------------------------------------
[19/09/2013 13:25:38] Image for Windows 2.82a (GUI)
[19/09/2013 13:25:38] Starting with VSS...
imagew.exe /b /d:w0@0x2 /f:"F:\IFW-Win7-013" /comp:14 /desc:"with VSS"
[19/09/2013 13:25:38] Attempting to Create VSS Snapshot...
[19/09/2013 13:25:55] VSS Snapshot Created Successfully.
[19/09/2013 13:25:56] Backup: Drive 0 (C Windows7 Partition (02) 124446 MiB HPFS/NTFS
[19/09/2013 13:25:56] To: F:\IFW-Win7-013.TBI
[19/09/2013 13:32:21] INFO: Total Sectors:254865232 Total Allocated:78841808
[19/09/2013 13:32:21] INFO: 51725328 Sector(s) backed up
[19/09/2013 13:32:21] Notifying VSS that backup completed...
[19/09/2013 13:32:22] Operation Completed with Error Code 0
[19/09/2013 13:32:23] Stop

But the question is still valid - it is not clear to me why a phylock image is so much bigger? It seems a VSS lock normally results in omitting ALL items in the 'not to backup' registry key, and setting the two flags flags in IFL effectively just makes sure that happens. It still happens without those flags being set. PHYLOCK on the other hand, backs up everything but does something that effectively omits pagefile.sys and hiberfil.sys without actually removing the space (by saving all zeros ).

So one might say a phylocked image is more complete, but is needlessly large ?

 

The VSS image is smaller because more files are omitted. Both omit pagefile and hibernate file.

 

It seems to me that PHYLock was developed before VSS (so that early versions of IFW could lock system files). Nowadays VSS is very refined and just about every Windows app is VSS-aware, so I just don't see a valid reason to continue to use PHYLock (with possible exception of Rollback Rx users).

If anyone disagrees with this, I'd sure like to know your reasoning.

TS

 

I continue to use Phylock and never gave VSS a look. I would be interested in a definitive, SAFE answer to that question too.

 

I'm with The Shadow on this; I use VSS for the very reasons he cited. But I too am open to considering any logical arguement in favor of Phylock.

Cruise

 

It comes down to personal preference. I prefer PHYLock as I don't want files omitted from the image. PHYLock won't work on my wife's Asus tablet so VSS is used.

The following is from a TeraByte forum post...

 

The page file and hibernate file amount to approx 5Gb in my case, which is omitted from both a VSS and a PHYLOCKed image, but my checking whilst booting off a Linux CD show me that the big backup size difference comes from another place. It is System Volume Information, totalling 82 items size 8.6Gb.

Now you cannot see what is in there unless you use Linux, and when you do, it is quite a few restore points, but mainly a subdirectory WindowsImageBackup. I suspect that is VSS snapshot of some description. All that is eliminated in a VSS image.

The point of interest to many people is that a PHYLOCK image does include these things, when actually they are not always necessary. For example, there is not a lot of point in allowing more than say 1Gb for restore points, if you are taking regular images.

This link http://indrajitc.wordpress.com/2008/03/25/reclaiming-disk-space-from-system-volume-information/ shows you how to minimise things in SystemVolumeInformation, where most people can save many Gb and some save extraordinary amounts of waste storage. Everone should be aware of this. I myself was aware, but failed to act on it. Because you cannot see all that space in almost any Windows situation, you don't make the connection between restore points and wasted disk space very easily.

Of course, there are other ways of removing that space than typing into a command box.