Thanks! Does linkfile concept cause any performance degradation since now it will need to request every node if file exists or not? On Fri, Mar 18, 2011 at 10:19 AM, Amar Tumballi <amar at gluster.com> wrote: > Hi Mohit, > Sorry for the delay.. answer inline.. >> >> Thanks for getting this release out. I was going through the release >> and didn't quite understand "fix layout by issuing re-balance" means. >> Does it mean if server is added or removed and then new files created >> in "existing" directory will not hash accross all the nodes (including >> new nodes)? >> > > Currently, the hashing range/layout is different per directory, and is set > ?during the mkdir(). Hence, when a new node is added, new files created > under existing directory will not be hashed to new nodes. that is handled by > issuing a 'gluster rebalance' command. > And when there is a 'remove-brick' command, the existing hash layout in the > directory will miss some ranges which belongs to those new nodes, hence > again, you would need 'gluster rebalance' which does fix the layout issues. > >> >> And another question is it necessary to run "migrate-data" after >> running "fix-layout"? If answer is "no" then after fixing layout >> (fix-layout) wouldn't it confuse gluster hashing algorigthm in anyway >> when accessing existing files? >> > > answer to first part of the question is 'no' (ie, you don't need to run > 'migrate-data' always after 'fix-layout'). Internally the hashing algorithm > is fool proof to handle it. We have a concept called linkfile which does > this. > Regards, > Amar >
