From mboxrd@z Thu Jan 1 00:00:00 1970 From: di wang Date: Mon, 06 Apr 2009 18:02:14 -0400 Subject: [Lustre-devel] [RFC] two ideas for Meta Data Write Back Cache In-Reply-To: References: <200904061339.02850.alexander.zarochentsev@sun.com> <20090406100345.GO3199@webber.adilger.int> Message-ID: <49DA7BE6.6070006@sun.com> List-Id: MIME-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit To: lustre-devel@lists.lustre.org > 2) "create w/o name" (this is what MDT accepts these days) isn't operation, > it's partial operation. but for partial operations we already have OSD > - clear, simple and generic. having one more "partial operations" adds > nothing besides confusion, IMHO > I am not sure you can( or should) translate all the MD partial operation into object RPC for these partial MD operation. For example rename, (a/b ---> c/d, a/b in MDS1, c/d in MDS2). RPC goes to MDS1. 1) delete d (entry and object) from c in MDS2. 2) create b entry under c in MDS2. 3) delete b entry under a in MDS1. So if you do 1) and 2) by object rpc (skip mdd), then you might need create create all 4 objects (a and b are local object, c and d are remote object), and permission check locally (whether you can delete d under c). Not sure it is a good way. And also some quota stuff are handled in these partial operation in remote MDD, so I am not sure we should skip mdd totally here. Am I miss sth? Thanks WangDi