From mboxrd@z Thu Jan 1 00:00:00 1970 From: Alex Zhuravlev Date: Tue, 19 Feb 2008 19:27:51 +0300 Subject: [Lustre-devel] storing SOM epoch in EA In-Reply-To: <18363.511.252694.497169@gargle.gargle.HOWL> References: <47BAA607.1000600@sun.com> <47BAAF3F.6030301@sun.com> <200802191359.47379.vitaly@sun.com> <47BAB962.8010901@sun.com> <47BABB01.8060402@sun.com> <18363.511.252694.497169@gargle.gargle.HOWL> Message-ID: <47BB0387.2010802@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 Nikita Danilov wrote: > One possible point here is that OSD has to do fid->ino translation > anyway, and it makes sense to use the same index to store other > information besides inode number. That is, we can use "object index" iam > file to map fid into (ino, gen, ioepoch, LOV, ...) records, and this > would not cause any additional seeks. The downside here is that object > index is so heavily used, that making its records larger is going to > increase the amount of IO significantly, so it only worth to place there > things that we are absolutely sure will be needed for every inode. well, we also need to update ioepoch when we update size/blocks. thanks, Alex