natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-4 11:27 pm
Anyone else getting this "Size on Disk" Anomaly?So I was checking some file sizes on my PC and noticed that when I checked the properties on a file or folder on my local drive, the "File size" and the "Size on disk" would either be the same or very close to being the same. I then checked files stored on my Synology Nas on the network and the sizes are grossly different. No, I mean like night and day different. WTH?
I have a similar computer setup with identical NAS at a remote location in another city, so I checked file sizes there. Files and folders on the C drive had similar file sizes on both "file size" and "Size on disk" .... then I check the NAS and it also shows that the "file size" and "size on disk" are the same ... or pretty close to it.
The only difference between my home network and the remote network is the OS. I'm using Win8.1 at home and Win7 at the remote location. It seems like when Windows 8.1 accesses files on the network the File size and the Size on disk are way out of wack.
Is this really related to my OS or do I have some other deeply seated issues going on?
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This should explain it for you. » tinyurl.com/mue7calBlob |
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natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-5 10:06 am
Yeah, I checked that out prior to posting. My question is why does windows 7 and windows 8.1 behave differently with file sizes on the network. |
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to natedj
Is there a difference in allocation unit size between the two OSs?
Blob |
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natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-7 10:41 am
I was under the impression that by default the two OS would have the same allocation unit size. |
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That is my assumption also.
Blob |
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natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-7 10:51 am
Just verified it with chkdsk . They both have the same file allocation unit size. |
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natedj |
natedj
Premium Member
2013-Dec-7 10:54 am
Its funny, we just got new Windows 8.1 PC's at the job and when I checked the files on the NAS at work I get the same results as my home system with the outrageous "size on disk" numbers. |
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dave Premium Member join:2000-05-04 not in ohio |
to natedj
The file system on the disk is the thing that 'has' the allocation size. It travels with the disk; it cannot be different between two different operating systems.
So, the thing that controls the allocation unit size of files on the NAS is... the NAS.
However, despite allocation size, it's perfectly possible for an program to decide it's sensible to store 1 byte of data in a 53 gigabyte file. This is not an allocation unit size issue, it's just over-allocation of space on a particular file. That is probably not happening, but it could be.
I suppose I should point out that directories (folders) on Windows don't actually 'have' sizes -- that is, the size of a directory itself is always reported (at the program level) as 0. Explorer adds up the sizes of everything in the directory, recursively, and says that's the size of the folder.
Other operating systems, such as the Linux system (I guess) running on the NAS do have directory sizes. Though I don't see how that could affect anything here.
It's possible that the NAS is bungling the protocol that is used to report the sizes of files. Due to ancient history, it's a mess. Perhaps the NASes have different firmware and one of them has a bug fixed.
I'd look at indvidual files in the directory and see whether there are radical per-file differences.
I'd also run a network sniffer (Network Monitor, Wireshark) to see what's coming across the wire: this would absolutely determine who was at fault. |
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OZO Premium Member join:2003-01-17 |
OZO to natedj
Premium Member
2013-Dec-7 3:36 pm
to natedj
Check it with TreeSize and see what's going on. |
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natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-7 4:32 pm
Yes the NAS is what controls the allocation unit size on the NAS but my quandary is why would Win7 and Win8.1 get different results when they both have the same file allocation unit size. Windows 8.1
Windows 7
Above are screen shots from my Win8.1 desktop and my wife's Win7 desktop both on the same network, accessing the same Folder on the same NAS. (BTW the NAS is running on Linux)
I'm leaning towards Win8.1 being at fault because the same weird behavior is happening at work only with Win 8.1 OS's. Is anyone else here experiencing this with W8.1 and files on network.
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darciliciousCyber Librarian Premium Member join:2001-01-02 Forest Grove, OR |
I can't duplicate that issue on my Windows 8.1 system for files stored on a WHS v1 box. |
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dave Premium Member join:2000-05-04 not in ohio |
to natedj
said by natedj:... they both have the same file allocation unit size. First, let's squash this line of argument. The OS does not have an 'allocation size'. If you look, for example, at the allocation unit size for C:, then what you've got is the allocation unit size for C:, and not for any other file system volume on the same computer, must less for any volume on the other sode of a network link. So, if we are talking about the same file system volume on the same NAS device, there's only one 'allocation unit size' involved - the one on the disk in question. -- My guess is that it's more likely to be a NAS protocol incompatibility. But that's probably because I used to work in that area, and know how many ways it can be got wrong. Perhaps the NAS doesn't send a size-on-disk and therefore the client 'guesses' differently. Two requests: 1. Can you post screen shots for the properties of a single file in that folder? (From both Win7 and Win8 if possible) 2. Any chance of installing Wireshark on the Win8 system and capturing traffic to the NAS when you're getting that size info? |
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natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-7 6:34 pm
I'm totally at sea with Wireshark so I'll try a capture with it and sent you the file via IM. Screen shots of file posted Windows 7
Windows 8.1
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natedj |
natedj
Premium Member
2013-Dec-7 6:39 pm
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elwoodbluesElwood Blues Premium Member join:2006-08-30 Somewhere in |
to workablob
1.5tb slack? for 7 files. That can't be it. |
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dave Premium Member join:2000-05-04 not in ohio |
to natedj
OK, here's the relevant part of a response to a query for 'standard info' for the file Peachpit.Press.The.Photoshop.CS5.Pocket.Guide.May.2010.pdf which is in your screen shot above.
QUERY_PATH_INFO Data
Allocation Size: 268435456
End Of File: 5686822
Link Count: 1
Delete Pending: Normal, no pending delete (0)
Is Directory: This is NOT a directory (0)
Unknown Data: 0000
Size around 5M, allocation 256M. This is what the NAS server is saying. The Windows system is apparently innocent in all this. |
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dave |
dave
Premium Member
2013-Dec-7 10:17 pm
Later at frame 158 the client needs to actually open the file. Here's the response. The size data are identical -- i.e., it's not just a buggered-up message. As far as we can tell, the file really has that allocation on the NAS. NT Create AndX Response (0xa2)
Word Count (WCT): 42
AndXCommand: No further commands (0xff)
Reserved: 00
AndXOffset: 0
Oplock level: Batch oplock granted (2)
FID: 0x4fe6 (\Manuals\photoshop tutorials pdf\Peachpit.Press.The.Photoshop.CS5.Pocket.Guide.May.2010.pdf)
Create action: The file existed and was opened (1)
Created: Jan 1, 2013 11:52:15.999999900
Last Access: Dec 7, 2013 17:48:15.999999900
Last Write: Dec 22, 2012 11:30:36.999999900
Change: Dec 22, 2012 11:30:36.999999900
File Attributes: 0x00000020
Allocation Size: 268435456
End Of File: 5686822
File Type: Disk file or directory (0)
IPC State: 0x0007
Is Directory: This is NOT a directory (0)
Byte Count (BCC): 0
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dave |
to natedj
So why are the results from the two systems so different?
Do you want to get the same sort of trace from the Windows 7 system? |
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natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-7 10:57 pm
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dave Premium Member join:2000-05-04 not in ohio |
dave
Premium Member
2013-Dec-7 11:07 pm
That has exactly the same sort of response messages with the same size fields.
So, the NAS is consistently saying '5MB written, 256MB on disk' but for some reason Windows 7 doesn't believe it. |
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natedjElected Premium Member join:2001-06-06 Irmo, SC |
natedj
Premium Member
2013-Dec-8 2:31 pm
I see that I'm not alone, there are about two to three topics in the Synology forums about this, but no solution yet either. |
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dave Premium Member join:2000-05-04 not in ohio |
dave
Premium Member
2013-Dec-8 2:37 pm
I'm not familiar with the Synology NAS, is there any way to find out what the local file system thinks of the file?
Something like the Linux 'stat' command on the file would be good. That requires you to be able to get to a shell, though. |
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