Re: Real size vs. Allocated size...

["Steve Landess" <sjl_abc@xxxxxxxxxxx>]

Ken -

In your case, the "allocated" size is probably the _minimum_ amount of 
storage than can be allocated for the IFS object...it is probably the 
"cluster size" on the disk, or the minimum number of sectors that must be 
allocated for an IFS object.

This phenomenon can also be observed on any PC hard disk...open a text 
editor, put a single character into a text document, and save it to 
disk...then go back and see how much storage it occupies.

As a test, I just used Notepad to create a text file named XXX.TXT, and put 
a single 'A' into it.
when I use DIR to view the files in the folder, it shows a size of 5. 
However, when I use Explorer to view the properties of the file, it says 
that 4096 bytes are allocated, so on my PC the cluster size is probably 4096 
bytes.

Regards,
Steve

----- Original Message ----- 
From: "Graap, Ken" <keg@xxxxxxxxxxxxx>
To: "'Midrange'" <midrange-l@xxxxxxxxxxxx>
Sent: Monday, January 24, 2005 10:36 AM
Subject: Real size vs. Allocated size...


> We are storing "millions" of small TIFF images in the IFS.
>
> After doing this for a couple of months we have noticed that they are 
> taking
> up much more space than originally planned...
>
> When I look at the attributes for one of them I see this:
>
> Size of object data in bytes . . . . . :   33936
> Allocated size of object . . . . . . . :   65536
>
> OS/400 HELP tells me that "allocated size" is:
>
> The number of bytes that have been allocated for the object.  The
> allocated size varies by object type and file system.  For example, the
> allocated size includes the object data size as well as any logically
> sized extents to accommodate anticipated future requirements for the
> object data.  It may or may not include additional bytes for attribute
> information.
>
> I'm not completely sure if the allocated size is taking up "real" disk
> space...
>
> These files do not need additional space allocated. There are what they 
> are
> and will not grow in size...
>
> Does anyone know how I can make the allocated size equal to the real size,
> when I create new objects like this in the IFS or do I even have to worry
> about this?
>
> Kenneth
>
> ****************************************
> Kenneth E. Graap
> IBM Certified Specialist
> AS/400e Professional System Administrator
> NW Natural (Gas Services)
> keg@xxxxxxxxxxxxx
> Phone: 503-226-4211 x5537
> FAX:    603-849-0591
> ****************************************
>
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