[zfs-discuss] Checksum question.

Brian McBride
Wed, 02 Jul 2008 05:49:13 -0000

I have some questions from a customer about zfs checksums.
Could anyone answer some of these? Thanks.

Brian

Customer:
 I would like to know more about zfs''s checksum feature.  I''m
guessing
it is something that is applied to the data and not the disks (as in
raid-5).

 For performance reasons, I turned off checksum on our zfs filesystem
(along with atime updates).  Because of a concern for possible data
corruption (silent data corruption), I''m interested in turning checksum
back on.  When I do so, will it create checksums for existing files or
will they need to be rewritten?  And can you tell me the overhead
involved with having checksum active (CPU time, additional space)?

--
Brian McBride
System Support Engineer
Sun Microsystems
Cell: 206-851-1028
Email: brian.mcbride at sun.com