Re: [sleuthkit-users] TSK-4.4 and SlackFiles

[Luís F. N. <lfc...@gm...>]

Thank you, Brian, for your explanation! No problem for our application,
just curious to know if it was a bug or, if not, why it is there.

But, currently, no slack files are created for VSC files and other files
with initsize smaller than allocated size. I thought slack is created only
when allocated > logical size (based on line 1001 of db_sqlite.cpp)

And is the allocated size 4096 from istat output? I do not know where the
slack size of 2.026.496 bytes came from...

2017-01-31 18:05 GMT-02:00 Brian Carrier <ca...@sl...>:

> Actually, making this decision could incur some significant overhead for a
> step that (at least in Autopsy) we try to keep as fast as possible.  Is
> your application impacted by the fact that there is a large and empty slack
> file or were you just curious if it was a bug?
>
>
>
> On Tue, Jan 31, 2017 at 2:54 PM, Brian Carrier <ca...@sl...>
> wrote:
>
>> Yea, this looks like "VDL Slack".  Same general idea as in Issue 466 (
>> https://github.com/sleuthkit/sleuthkit/issues/466), but in this case the
>> file has 1K of initialized size.
>>
>> I suppose this "slack" file is a bit wasted though because no blocks were
>> allocated to it. So, there will be no real content for it.
>>
>> I'll make an internal story to keep track of this and maybe Ann will be
>> able to take a look at not making these if they are going to be all for
>> address 0.
>>
>>
>>
>> On Tue, Jan 31, 2017 at 10:55 AM, Luís Filipe Nassif <lfc...@gm...
>> > wrote:
>>
>>> Hi Brian,
>>>
>>> Thank you very much for your attention. The output of
>>> FsContent.getMetaDataText() (equals to istat right?) is below. The
>>> system.LOG-slack size is 2.026.496 bytes and system.LOG size is 1024 bytes.
>>>
>>> details of /img_PC-HP.dd/vol_vol2/WINDOWS/system32/config/system.LOG-sl
>>> ack
>>>
>>> MFT Entry Header Values:
>>> Entry: 4106        Sequence: 1
>>> $LogFile Sequence Number: 79246281526
>>> Allocated File
>>> Links: 1
>>>
>>> $STANDARD_INFORMATION Attribute Values:
>>> Flags: Hidden, Archive
>>> Owner ID: 0
>>> Security ID: 281  (S-1-5-32-544)
>>> Last User Journal Update Sequence Number: 105272096
>>> Created: 2004-09-02 08:00:12.000000000 (Hora oficial do Brasil)
>>> File Modified: 2011-09-16 14:33:38.375000000 (Hora oficial do Brasil)
>>> MFT Modified: 2011-09-16 14:33:38.375000000 (Hora oficial do Brasil)
>>> Accessed: 2011-09-16 14:33:38.187500000 (Hora oficial do Brasil)
>>>
>>> $FILE_NAME Attribute Values:
>>> Flags: Hidden, Archive
>>> Name: system.LOG
>>> Parent MFT Entry: 3982 Sequence: 2
>>> Allocated Size: 4096   Actual Size: 1024
>>> Created: 2004-09-02 08:00:12.000000000 (Hora oficial do Brasil)
>>> File Modified: 2004-09-02 08:00:12.000000000 (Hora oficial do Brasil)
>>> MFT Modified: 2004-09-02 08:00:12.000000000 (Hora oficial do Brasil)
>>> Accessed: 2004-09-02 08:00:12.000000000 (Hora oficial do Brasil)
>>>
>>> $ATTRIBUTE_LIST Attribute Values:
>>> Type: 16-0 MFT Entry: 4106 VCN: 0
>>> Type: 48-4 MFT Entry: 4106 VCN: 0
>>> Type: 128-0 MFT Entry: 40678 VCN: 0
>>>
>>> Attributes:
>>> Type: $STANDARD_INFORMATION (16-0)   Name: N/A   Resident   size: 72
>>> Type: $ATTRIBUTE_LIST (32-5)   Name: N/A   Resident   size: 96
>>> Type: $FILE_NAME (48-4)   Name: N/A   Resident   size: 86
>>> Type: $DATA (128-6)   Name: N/A   Non-Resident   size: 1024  init_size:
>>> 1024
>>> 847844 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0 0
>>> 0 0 0 0 0 0 0
>>>
>>> 2017-01-31 12:56 GMT-02:00 Brian Carrier <ca...@sl...>:
>>>
>>>> Hi Luis,
>>>>
>>>> My guess is that it's a file that has preallocated a large amount of
>>>> space, but that has not fully used it yet. NTFS allows this.  If you read
>>>> the file, TSK will only show you the space that is used.  Reading the
>>>> slack, gives you the rest.
>>>>
>>>> If you run 'istat' on one of these files and send it along, we can
>>>> confirm.
>>>>
>>>> thanks,
>>>> brian
>>>>
>>>>
>>>> On Tue, Jan 31, 2017 at 7:04 AM, Luís Filipe Nassif <
>>>> lfc...@gm...> wrote:
>>>>
>>>>> Hi folks,
>>>>>
>>>>> I am upgrading to tsk-4.4 to benefit from the new support to
>>>>> slackfiles from java bindings. But I noticed some slackfiles larger than
>>>>> the cluster size (4k) are created in database. Some of them have megabytes
>>>>> of size and its contents are accessible. Is it expected to have slackfiles
>>>>> larger than cluster size? Could someone explain?
>>>>>
>>>>> Thanks,
>>>>> Luis Nassif
>>>>>
>>>>> ------------------------------------------------------------
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>>>>>
>>>>>
>>>>
>>>
>>
>