Question about 2kb filesystems

[Dennis Page]

In article <978 at vsi.COM> friedl at vsi.COM (Stephen J. Friedl) writes:
>     A customer of mine has a 3B2/600 running System V Release
>3.2.1, with an Informix-SQL application (ver 2.10.00B).  We just
>converted the filesystem with the actual *large* database files
>to be a 2kb filesystem, and the customer notices that everything
>runs slower.

Did you test the rotation gap when you changed logical block sizes?  What
is the time difference between moving 1k & 2k blocks?  Did they change mkfs
to use *logical* gap size instead of physical (512) gap size?

Did you check to make sure that the data area still begins on a cylinder
boundary?  (Twice the logical block size means twice the boundary size for
superblock & inode tables.)

So many questions!  :-)

Btw: Be wary of the possibility of mkfs using logical blocks for gapping
and fsck using physical blocks.  This nasty screwup, especially if you do
fsck -s by habit.  I don't know if AT&T 3.2 has this disease (I really
doubt it -- they don't have it in 3.1.1) , but Unisys 3.x sure does.
-- 
Good health is merely the slowest rate at which one can die.