Re:Re: Re: compression btrfs

2013-03-26 Thread yiletian
I think the biggest problem is how we can reclaim the space when the extent is a compressed one. In this case, we may need to read and decompress data in the extent, and then compress the valid range to generate a new extent. Is this process a performance killer? At 2013-03-27 02:03:57,"Josef Bac

Re: Re: compression btrfs

2013-03-26 Thread Josef Bacik
On Tue, Mar 26, 2013 at 10:27:34AM -0600, yiletian wrote: > Yes, I use compress-force=zlib for my partition. > > Consider this scenario. > > We first write a file with size of 256KB. Assume all data is compressed to > 128KB size, > btrfs create a extent item in extent-tree to record the 128KB di

Re: compression btrfs

2013-03-26 Thread Josef Bacik
On Mon, Mar 25, 2013 at 10:03:20PM -0600, lonat_fr...@163.com wrote: > Hi everyone, > >   I have used btrfs as a work partition with compression=zlib. The > compression ratio is not satisfied to me.  > So you probably want compress-force=zlib. With just compress we will bail out of the compres