Re: commit: ldap/doc/man/man5 slapd-bdb.5

[Howard Chu <hyc@symas.com>]

Hallvard B Furuseth wrote:
> Howard Chu writes:
> > Besides, no worthwhile filesystems in common use today use 512 byte blocks.
>
> Famous last words...  Next FS revolutions will see - oh, blocks of
> blocks where the inner blocks often are small.  Or whatever.

Heh. Total digression now. But no, not at all.

This isn't like saying "no one will ever need more than 640K." Historical 
trends shows that resource sizes only ever increase, never decrease. Storage 
densities increase, capacities increase, and the overhead of managing the 
storage increases. The only way to keep a handle on such large capacities is 
to use larger and larger allocation units. The hard drive industry has been 
trying to push for 4KB sectors as a standard for years, because the command 
overhead with 512 byte sectors is too high. The SSD industry is using flash 
memory devices with erase blocks at 128KB and growing.

Filesystem block sizes can only increase, to keep up, otherwise performance 
will be abysmal. The only thing to be afraid of here is that BDB's 64K limit 
may already be too small for a lot of common technologies today.
--
  -- Howard Chu
  CTO, Symas Corp.           http://www.symas.com
  Director, Highland Sun     http://highlandsun.com/hyc/
  Chief Architect, OpenLDAP  http://www.openldap.org/project/