Showlock

[Dennis Malen]

Top Post

Just saw this after I replied with my question to Ken. Thanks for taking the
trime out and providing us all with such an extensive answer.

AIX file system does not have a limitation. Journaled file systems can be
expanded as needed.

-----Original Message-----
From: filepro-list-bounces+dmalen=malen.com at lists.celestial.com
[mailto:filepro-list-bounces+dmalen=malen.com at lists.celestial.com] On Behalf
Of Brian K. White
Sent: Tuesday, June 18, 2013 3:57 PM
To: filepro-list at lists.celestial.com
Subject: Re: Showlock

On 6/18/2013 1:32 PM, Richard Kreiss wrote:
>
>
>> -----Original Message-----
>> From: Dennis Malen [mailto:dmalen at malen.com]
>> Sent: Tuesday, June 18, 2013 12:15 PM
>> To: Richard Kreiss; ken_wakeman at me.com; 'Kenneth Brody'
>> Cc: 'FilePro Mailing List'
>> Subject: RE: Showlock
>>
>> Top Post
>>
>> Still not clear.
>
> Dennis,
>
> Fp, in the days of smaller drives, allowed for adding key/data extents to
the same or different drives.  Today with the larger drive capacity, the
only time one would want to do this is when the file size is nearing the 2GB
limit on a 32bit OS.
>
> I don't recall exactly what the naming convention is for these extents.

To add extents:

# touch keyqualxn dataqualxn
# chown filepro key* data *
# chmod 600 key* data*
(chmod and chown must be run *in this order*, or, just run a recent version
of setperms instead of chmod & chown)

Where qual is a qualifier (including nothing for unqualified), and n may be
anything from 1 to at least 9. I don't know if they can go beyond 9. I think
it must start at 1 and count up with no breaks if you need more than one
extent. IE, if you have one extent it must be x1. If you have 2 extents they
must be x1 and x2, etc. Each extent adds another 2G (or whatever your
OS/filesystem/fp binary max file size is) to the available "file size" to
the filepro file, up to the record limit in filepro which I don't remember,
but @rn are 9,.0 edit.

So, for unqualified with only one extent:

keyx1 datax1

For 3 extents in qualifier foo:

keyfoox1 keyfoox2 keyfoox3 datafoox1 datafoox2 datafoox3

Yes this means there is ambiguity between unqualified with extents, and
qualifiers that happen to be named x1 - x9. So the first extent of
unqualifed key is "keyx1", and the regular key in qualifier x1 is also
"keyx1".
All I can say about that is either try it and see what fp does, or "don't do
that" meaning don't make any qualifiers named x1, x2, ... x9.

I don't remember if you have to do indexes too and I never use blob or memo
but I imagine that blob and memo at least must also be extendable by the
same rules.



The limit per individual file is not simply 2G on 32bit OS. There are at
least 3 possible things that impose a limit, the OS, the filesystem, and the
fp binaries.

You could for instance have an OS that can do 64bit file i/o, and fp
binaries that can do 64bit file i/o, Meaning both could handle file sizes in
the terabytes, but if you are writing to a fat32 filesystem, then the max
file size is 4G because that is the limit in fat32.
There are also filesystem-specific tuning/layout options that affect max
file size where if you have an ext3 filesystem with 1k block sizes, your max
file size is 16 GB, but if you have a ext3 filesystem with 4k block sizes,
your max file size is 2 TB. The max file size in various 64bit filesystems
ranges from as little as 16 GB all the way to 8 EB

Generally though:
older 32bit OS & binaries = 2G
newer linux 32bit os & binaries can do 64bit file i/o = 2TB or more old or
new, 64bit any os & binaries = 2 TB or more

You could also be using old 32bit fp binaries on an otherwise 64bit OS and
filesystem, and in that case the limit would be 2G, unless the binaries are
32bit but new enough to support 64bit file i/o.

You are on AIX? your max file size depends on the same things as above but
for aix. 32 or 64 bit kernel? what filesystem? And possibly on options
chosen at the time the filesystem was created, which we can not know. For
JFS2 it looks like even for a 32bit kernel 1 TB is a safe bet for max file
size.

http://publib.boulder.ibm.com/infocenter/pseries/v5r3/index.jsp?topic=/com.i
bm.aix.baseadmn/doc/baseadmndita/fs_size_limit.htm

--
bkw
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