[CentOS] *BAD*gran_size

Thu Jun 13 15:50:25 UTC 2013
m.roth at 5-cent.us <m.roth at 5-cent.us>

CentOS 6.4, current, Dell PE R720.

Had an issue today with a bus error, and googling only found two year old
references to problems with non-Dell drives (we just added two WD Reds,
and mdadm raided them).

So, looking through dmesg and /var/log/messages, I ran into a *lot* of
G
 gran_size: 128K        chunk_size: 256K        num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 512K        num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 1M  num_reg: 10     lose cover RAM: 0G
 gran_size: 128K        chunk_size: 2M  num_reg: 10     lose cover RAM: 0G
 gran_size: 128K        chunk_size: 4M  num_reg: 10     lose cover RAM: 0G
 gran_size: 128K        chunk_size: 8M  num_reg: 10     lose cover RAM: 0G
 gran_size: 128K        chunk_size: 16M         num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 32M         num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 64M         num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 128M        num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 256M        num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 512M        num_reg: 10     lose cover
RAM:
0G
 gran_size: 128K        chunk_size: 1G  num_reg: 10     lose cover RAM: 0G
*BAD*gran_size: 128K    chunk_size: 2G  num_reg: 10     lose cover RAM: -1G

Googling finds various threads, and a bug or two, and one person has an
answer of setting this in the kernel line in grub. HOWEVER, the one person
who gave that thread's O/P what to put never responded to *how* he chose
those parms.

Anyone here have any idea how to chose them?

      mark