From mboxrd@z Thu Jan 1 00:00:00 1970 From: Eric Barton Date: Tue, 11 Oct 2011 14:20:44 +0100 Subject: [Lustre-devel] IPv6 NIDs Message-ID: <06e901cc8818$95acbc60$c1063520$@com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org I'd like to canvass thoughts on how big an IPv6 compatible NID might be. We'd like to start anticipating changing to these NIDs so that current development at least doesn't dig us deeper into a hole (e.g. on the nidtable entries sent over the wire in imperative recovery). So here are some suggestions.... Current NID: 32 bit address-within LNET + 32 bit LNET number 64 bits / 8 bytes total IPv6 compatible NID: 1. Minimum: 128 bit address-within-LNET + 32 bit LNET number. 160 bits / 20 bytes total. 2. Hedge a little by reserving an additional (say) 32 bits for something we've not thought of yet and keeping the total a multiple of 64 bits to simplify alignment. 192 bits / 24 bytes total. 3. Hedge a lot with a nice round number. 256 bits / 32 bytes total. (2) gets my vote currently... Cheers, Eric Eric Barton CTO Whamcloud, Inc. Tel: +44 (117) 330 1575 Mob: +44 (7920) 797 273