Ext4 devel interlock meeting minutes (Nov. 29 2006)

Ext4 devel interlock meeting minutes (Nov. 29 2006)

[Avantika Mathur LTC]

Ext4 Developer Interlock Call: 11-29-06 Minutes

Attendees: Mingming Cao, Eric Sandeen, Dave Kleikamp, Jean-Pierre Dion, 
Valérie Clément, Jean-Noel Cordenner, Takashi Sato, Ted Ts'o, Avantika 
Mathur

- Preallocation:
  -- Suparna is has started working on implementation and will 
temporarily use ioctls as interface.
  -- Discussed XFS implementation details posted by Eric, why there are 
two methods, one zeroing out blocks, and the other setting flag in 
preallocated extents.
  -- Eric will work on a proposal for preallocation implementation using 
posix_fallocate and fcntl

- Nanosecond Timestamp:
  -- Reviewed status of Patch from Andreas Dilger in June
  -- Before moving forwars, we need to address design question of 
whether nanosecond timestamps should be supported in older filesystems 
with 128 byte inodes.  Will this feature be backported to ext3?
  -- Ted will reopen this issue on the mailing list
  -- Current plan is to only implement finer granularity timestamps for 
larger inodes, unless there is someone who feels it is critical to have 
them in current inodes.

- Defragmentation Patches:
  -- Takashi is working on addine improvements including support for 
quotas. 
  -- Will release new patch set in early December

- e2fsprogs: No updates to e2fsprogs since last week.
  -- New WIP released week ago; includes some recent patches including 
struct defs for new features
  -- Ted is still working to merge extents patches and will report 
progress next week

- New Wiki: ext4.wiki.kernel.org  Still a lot of work to be done to set 
it up.
  -- We will keep all interlock agendas and minutes here
  -- Will create ext4 roadmap with details on implementations for each 
feature

- Big Block Group patches:
  -- Valérie posted patches last week
  -- Need a clearer description of why this feature is needed and what 
the benefits are
  -- Decide whether it is a necessary feature and if all large 
filesystems should be using it.
  -- Ted will reply to Valérie's patches asking about specific benefits 
and requirements.
  -- Current thoughts on benefits of large block group size:
     o increase file system size
     o reduce file fragmentation because less extents are needed for 
large files
     o Reduce number of block descriptors, which reduces mkfs and fsck 
times for large filesystems

Re: Ext4 devel interlock meeting minutes (Nov. 29 2006)

[Alex Tomas]

>>>>> Avantika Mathur LTC (AML) writes:

 AML>     o reduce file fragmentation because less extents are needed for
 AML> large files

say, current limit for a single extent is 2^15 blocks or 128MB.
after regular mke2fs, a group has ~125MB free.

thanks, Alex