From mboxrd@z Thu Jan 1 00:00:00 1970 From: Johann Lombardi Date: Wed, 28 May 2008 10:06:13 +0200 Subject: [Lustre-devel] Moving forward on Quotas In-Reply-To: References: <18490.63940.619731.992500@gargle.gargle.HOWL> Message-ID: <20080528080613.GN3582@lore> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org Hello Peter, On Tue, May 27, 2008 at 07:28:10AM +0800, Peter Braam wrote: > >> When a slave runs out of its local quota, it sends an acquire request to the > >> quota master. As I said earlier, the quota master is the only one having a > >> global overview of what has been granted to slaves. If the master can satisfy > >> the request, it grants a qunit (can be a number of blocks or inodes) to the > >> slave. The problem is that an OST can return "quota exceeded" (=EDQUOT) > >> whereas > >> another OST is still having quotas. There is currently no callback to claim > >> back the quota space that has been granted to a slave. > > Hmm - the slave should release quota. I don't think that the slave can make such a decision by itself since it does not know that we are getting closer to the global quota limit. Only the master is aware of this. Actually, the scenario I described above can no longer happen - with recent lustre versions at least - thanks to the dynamic qunit patch because the master broadcasts to all the slaves the new qunit size when it is shrunk. Cheers, Johann