On Wed, May 27, 2009 at 11:10:09AM -0300, Atila Romero wrote: > During a file write, if the compression doesn't proves to be economical > to a portion of the file, the whole file is marked as nocompress, and > subsequent writes don't use compression at all. This can be seen as a > feature, as it saves CPU in files like videos. But if the file is a dd > image of a disk, or other types of large files, this behavior is > undesirable, since different portions of the file will have different > compression ratios. > I only became aware of this after searching the source code, after > spending some hours trying to find out why the compression wasn't > working. This can be a really unexpected behavior for a end user who is > looking for compression. > The specific part of the code is at inode.c: > 477 <#l477> > /* flag the file so we don't compress in the future */ > 478 <#l478> btrfs_set_flag(inode, NOCOMPRESS); > > How about commenting line 478?
The plan is to add a flag for the file to make it always compress even when parts of the file do not compress well. -chris -- To unsubscribe from this list: send the line "unsubscribe linux-btrfs" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html
