Re: [zfs-discuss] zvol space consumption vs ashift, metadata packing

2011-10-10 Thread Daniel Carosone
On Tue, Oct 04, 2011 at 09:28:36PM -0700, Richard Elling wrote: On Oct 4, 2011, at 4:14 PM, Daniel Carosone wrote: I sent it twice, because something strange happened on the first send, to the ashift=12 pool. zfs list -o space showed figures at least twice those on the source, maybe

Re: [zfs-discuss] zvol space consumption vs ashift, metadata packing

2011-10-10 Thread Bob Friesenhahn
On Sat, 8 Oct 2011, Daniel Carosone wrote: This isn't about whether the metadata compresses, this is about whether ZFS is smart enough to use all the space in a 4k block for metadata, rather than assuming it can fit at best 512 bytes, regardless of ashift. By packing, I meant packing them full

Re: [zfs-discuss] zvol space consumption vs ashift, metadata packing

2011-10-10 Thread Jim Klimov
2011-10-08 7:25, Daniel Carosone пишет: On Tue, Oct 04, 2011 at 09:28:36PM -0700, Richard Elling wrote: On Oct 4, 2011, at 4:14 PM, Daniel Carosone wrote: What is going on? Is there really that much metadata overhead? How many metadata blocks are needed for each 8k vol block, and are they

Re: [zfs-discuss] zvol space consumption vs ashift, metadata packing

2011-10-10 Thread Bob Friesenhahn
On Mon, 10 Oct 2011, Jim Klimov wrote: Thus I proposed the second idea with a code-only solution to optimize performance (force user-configured minimal data block sizes and physical alignments) where metadata blocks would remain 512 bytes because the pool is formally ashift=9 - and on-disk data

Re: [zfs-discuss] zvol space consumption vs ashift, metadata packing

2011-10-10 Thread Richard Elling
[exposed organs below…] On Oct 7, 2011, at 8:25 PM, Daniel Carosone wrote: On Tue, Oct 04, 2011 at 09:28:36PM -0700, Richard Elling wrote: On Oct 4, 2011, at 4:14 PM, Daniel Carosone wrote: I sent it twice, because something strange happened on the first send, to the ashift=12 pool. zfs

Re: [zfs-discuss] zvol space consumption vs ashift, metadata packing

2011-10-04 Thread Richard Elling
On Oct 4, 2011, at 4:14 PM, Daniel Carosone wrote: I sent a zvol from host a, to host b, twice. Host b has two pools, one ashift=9, one ashift=12. I sent the zvol to each of the pools on b. The original source pool is ashift=9, and an old revision (2009_06 because it's still running xen).