Snapshot performances

[Emmanuel Dreyfus <manu%netbsd.org@localhost>]

Hello

On a busy mail server running NetBSD 7.1, I can reliabily reproduce
the following situation when using FFS snapshots: most processes get
stuck into tstile, load quickly raises to an unreasonable level,
nothing responds. I have not looked into the internals, but everything 
behaves likes if all I/O were serialized.

Is this known limitation? The man page does not state any caution on 
how to use snapshots, should we update it?

-- 
Emmanuel Dreyfus
manu%netbsd.org@localhost