[Ocfs2-devel] 40TB RAID and OCFS2 woes (inode64, JDB2, huge partition support, Volume might try to write to blocks beyond what jbd can address in 32 bits)

[Robert Smith]

Just thought I would let you guys know that creating a 20TB file was successful. I even appended data to the end of it. Any operations on the file are completely useless because they take way to long. A appended "hello" to the end of the file no problem, but tail -n 1 {filename} yielded nothing except a lot of disk read after 159minutes of waiting.

I don't really even know if this is good information or common knowledge.

dd bs=1000M count=20000 if=/dev/zero of=/data/storage/ReplayDataVolume001/biggest_yet_file

root at s2-replay02:/data/storage/ReplayDataVolume001# ls -aFl
total 1266312192
drwxr-xr-x 3 root root           3896 2009-12-31 23:31 ./
drwxr-xr-x 3 root root             88 2010-01-01 11:02 ../
-rw-r--r-- 1 root root     1048576000 2009-12-31 23:23 big_file
-rw-r--r-- 1 root root    10485760000 2009-12-31 23:24 bigger_file
-rw-r--r-- 1 root root   104857600000 2009-12-31 23:28 biggest_file
-rw-r--r-- 1 root root 20971520000006 2010-01-01 11:03 biggest_yet_file
drwxr-xr-x 2 root root           3896 2009-12-31 11:53 lost+found/
root at s2-replay02:/data/storage/ReplayDataVolume001#

-Robert


On Jan 1, 2010, at 5:08 AM, Joel Becker wrote:

> On Fri, Jan 01, 2010 at 04:36:02AM +0900, Robert Smith wrote:
>> Oh, I found it at line #2163 of fs/ocfs2/super.c.
>> 
>> I imagine that something as simple as the following would work, but perhaps I'll wait for your feedback.
>> 
>> 
>> /*
>>        if (ocfs2_clusters_to_blocks(osb->sb, le32_to_cpu(di->i_clusters) - 1)
>>> (u32)~0UL) {
>>                mlog(ML_ERROR, "Volume might try to write to blocks beyond "
>>                     "what jbd can address in 32 bits.\n");
>>                status = -EINVAL;
>>                goto bail;
>>        }
>> */
> 
> 	That should work.  The real solution will check based on the
> journal flags.  Be warned, there be tygers in here.
> 
> Joel
> 
> -- 
> 
> "But all my words come back to me
> In shades of mediocrity.
> Like emptiness in harmony
> I need someone to comfort me."
> 
> Joel Becker
> Principal Software Developer
> Oracle
> E-mail: joel.becker at oracle.com
> Phone: (650) 506-8127