Richard Elling <richard.ell...@gmail.com> writes: > On Feb 8, 2010, at 9:10 PM, Damon Atkins wrote: > >> I would have thought that if I write 1k then ZFS txg times out in >> 30secs, then the 1k will be written to disk in a 1k record block, and >> then if I write 4k then 30secs latter txg happen another 4k record >> size block will be written, and then if I write 130k a 128k and 2k >> record block will be written. >> >> Making the file have record sizes of >> 1k+4k+128k+2k > > Close. Once the max record size is achieved, it is not reduced. So > the allocation is: 1KB + 4KB + 128KB + 128KB
I think the above is easily misunderstood. I assume the OP means append, not rewrites, and in that case (with recordsize=128k): * after the first write, the file will consist of a single 1 KiB record. * after the first append, the file will consist of a single 5 KiB record. * after the second append, one 128 KiB record and one 7 KiB record. in each of these operations, the *whole* file will be rewritten to a new location, but after a third append, only the tail record will be rewritten. -- Kjetil T. Homme Redpill Linpro AS - Changing the game _______________________________________________ zfs-discuss mailing list zfs-discuss@opensolaris.org http://mail.opensolaris.org/mailman/listinfo/zfs-discuss
