On Sat, Sep 24, 2016 at 05:40:12PM +0500, Roman Mamedov wrote: > On Sat, 24 Sep 2016 15:26:14 +0300 > Alexander Tomokhov <alexoundos@xxxxx> wrote: > > > does setting No_COW on a file (chattr +C) imply disabling data checksumming on it? > > Yes. IIRC the reasoning was that it's more difficult to track checksums of > data which is being overwritten in-place (as opposed to CoW). It's because you can't update the data and the checksum atomically -- at some point in the writing process, they must be inconsistent. This is considered a Bad Thing. Hugo. > > may it disable checksumming only for newly written extents and keep for reading existing ones? > > You can't apply chattr +C to any files of non-zero length, so by definition > there won't be any pre-existing checksummed extents in that file. > > -- > With respect, > Roman -- Hugo Mills | Comic Sans goes into a bar, and the barman says, "We hugo@... carfax.org.uk | don't serve your type here." http://carfax.org.uk/ | PGP: E2AB1DE4 |
Attachment:
signature.asc
Description: Digital signature
