[NTLUG:Discuss] 4.5TB volume formats out to 95Gig *Half-way solved*

[Richard Geoffrion]

Richard Geoffrion wrote:
> Richard wrote:
>   
>> <snip>
>>
>> The new 4.5TB array is built and
>> configured as an LVM volume and I'm only seeing 95Gigs!
>>   
>>     
> Well, it appears that I'm gonna have to use 'parted' and use the new GPT 
> (GUID Partition Tables).  ...more to come...
>
>   
Maybe ext2/3 has a limitation!?!

Help from  
http://www.gnu.org/software/parted/manual/html_chapter/parted_7.html#SEC67  
seemed to be the key, but I had some strange results.  After following 
the instructions and creating my 'pv' on /dev/sdg the 'vg' showed that 
it was 4.1TB.
         PV /dev/sdg   VG prepress   lvm2 [4.09 TB / 0    free]

So I formatted it with the command:
     mke2fs -j -L PrepressDrive -O dir_index,has_journal,sparse_super -T 
largefile  /dev/prepress/drive

But after I mounted it, df still only showed 96gig.
     /dev/mapper/prepress-drive   95G   33M   91G   1% /prepress

So I unmounted it and formatted /dev/prepress/drive with reiserfs.  What 
do you know!  it sees all of the space!!!!!
     /dev/mapper/prepress-drive  4.1T   33M  4.1T   1% /prepress


So....I recreated the LVM volume on /dev/sdg1 (the partition created 
with 'parted') and formatted it with ext2 -- NO JOY!  Only 96Gig.  
Further research seems to show that EXT2/3 has a 4TB limit. But why the 
96GB???--space left over between the ext2/3 limit and the end of the 
disk space?

So my questions now are...
1) What filesystem SHOULD I use?   After reading some evil stuff about 
ReiserFS...I'm wary. (metadata vs block journaling)
2) If I'm using LVM, do I even NEED to partition the drive to see 
greater than 2TB? What is it on the system that determines the operating 
system's ability to use the drive space?
3) Any good hints on how to fill up and test 4TB of space to verify data 
integrity won't be compromised by something like ..say....a "drive wrap"?



-- 
Richard
'time to make the doughnuts'