Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-07-08 Thread Edward Ned Harvey
From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Bertrand Augereau is there a way to compute very quickly some hash of a file in a zfs? As I understand it, everything is signed in the filesystem, so I'm wondering if I can avoid reading

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-07-08 Thread Garrett D'Amore
On Thu, 2010-07-08 at 18:46 -0400, Edward Ned Harvey wrote: From: zfs-discuss-boun...@opensolaris.org [mailto:zfs-discuss- boun...@opensolaris.org] On Behalf Of Bertrand Augereau is there a way to compute very quickly some hash of a file in a zfs? As I understand it, everything is

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-07-08 Thread Peter Jeremy
On 2010-Jul-09 06:46:54 +0800, Edward Ned Harvey solar...@nedharvey.com wrote: md5 is significantly slower (but surprisingly not much slower) and it's a cryptographic hash. Probably not necessary for your needs. As someone else has pointed out, MD5 is no longer considered secure (neither is

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-07-08 Thread Garrett D'Amore
On Fri, 2010-07-09 at 10:23 +1000, Peter Jeremy wrote: On 2010-Jul-09 06:46:54 +0800, Edward Ned Harvey solar...@nedharvey.com wrote: md5 is significantly slower (but surprisingly not much slower) and it's a cryptographic hash. Probably not necessary for your needs. As someone else has

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-07-07 Thread Daniel Carosone
On Tue, Jul 06, 2010 at 05:29:54PM +0200, Arne Jansen wrote: Daniel Carosone wrote: Something similar would be useful, and much more readily achievable, from ZFS from such an application, and many others. Rather than a way to compare reliably between two files for identity, I'ld liek a way

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-07-07 Thread Mike Gerdts
On Tue, Jul 6, 2010 at 10:29 AM, Arne Jansen sensi...@gmx.net wrote: Daniel Carosone wrote: Something similar would be useful, and much more readily achievable, from ZFS from such an application, and many others.  Rather than a way to compare reliably between two files for identity, I'ld liek

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-07-06 Thread Arne Jansen
Daniel Carosone wrote: Something similar would be useful, and much more readily achievable, from ZFS from such an application, and many others. Rather than a way to compare reliably between two files for identity, I'ld liek a way to compare identity of a single file between two points in

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-05-18 Thread Bertrand Augereau
Thanks Dan, this is exactly what I had in mind (hashing the block checksums). You convinced me to do it independently from zfs. -- This message posted from opensolaris.org ___ zfs-discuss mailing list zfs-discuss@opensolaris.org

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-05-17 Thread Daniel Carosone
On Tue, May 11, 2010 at 04:15:24AM -0700, Bertrand Augereau wrote: Is there a O(nb_blocks_for_the_file) solution, then? I know O(nb_blocks_for_the_file) == O(nb_bytes_in_the_file), from Mr. Landau's POV, but I'm quite interested in a good constant factor. If you were considering the hashes

[zfs-discuss] Hashing files rapidly on ZFS

2010-05-11 Thread Bertrand Augereau
Hello everybody, is there a way to compute very quickly some hash of a file in a zfs? As I understand it, everything is signed in the filesystem, so I'm wondering if I can avoid reading whole files with md5sum just to get a unique hash. Seems very redundant to me :) Bottom line is I want to

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-05-11 Thread Darren J Moffat
On 11/05/2010 11:14, Bertrand Augereau wrote: Hello everybody, is there a way to compute very quickly some hash of a file in a zfs? As I understand it, everything is signed in the filesystem, so I'm wondering if I can avoid reading whole files with md5sum just to get a unique hash. Seems

Re: [zfs-discuss] Hashing files rapidly on ZFS

2010-05-11 Thread Bertrand Augereau
Is there a O(nb_blocks_for_the_file) solution, then? I know O(nb_blocks_for_the_file) == O(nb_bytes_in_the_file), from Mr. Landau's POV, but I'm quite interested in a good constant factor. -- This message posted from opensolaris.org ___ zfs-discuss