One thing this thread indicates is the need for a warning in mkfs.xfs - according to several developers, there is, I think, linear increase in allocation time to number of allocation groups. It would be helpful for the end user to simply issue a warning stating this when the AG count seems high with a brief explanation as to why it seems high. I would allow it, but print the warning. Even a simple linear check like agroups>500 should suffice for "a while". Paul On Mon, Jun 27, 2011 at 4:55 AM, Stan Hoeppner <stan@xxxxxxxxxxxxxxxxx> wrote: > On 6/26/2011 11:14 PM, Marcus Pereira wrote: >> Em 27-06-2011 00:33, Stan Hoeppner escreveu: >>> >>> I recommend 3 changes, one of which I previously mentioned: >>> >>> 1. Use 8 mirror pairs instead of 4 >>> 2. Don't use striping. Make an mdraid --linear device of the 8 mirrors >>> 3. Format with '-d agcount=32' which will give you 4 AGs per spindle >>> >>> Test this configuration and post your results. >> >> I am thanks for all advices. I will make the tests and post, may take >> some time. >> >> About all other messages. My system may not be a Ferrari but its not a >> Volks. I certainly do not have that many HDs in fiber channel, but the >> sever is a dual core Xeon 6 cores with HT. Linux sees a total of 24 >> cores, total RAM is 24GB. The HDs are all SAS 15Krpm and the system runs >> on SSD. They are dedicated to handle the maildir files and I have >> several of those servers running nicely. >> But I don’t want to make the thread about my system larger. > > So you do or don't have the excessive head seek problem you previously > mentioned? If not then use the mkfs.xfs defaults. > >> Yes, I don’t know much about XFS and Allocation groups, thanks for you >> all to help me a bit. > > You're welcome. Google should turn up a decent amount of information > about XFS allocation groups if you're interested in further reading. > >> At the end the reason why I opened the thread it the error and the >> developers should take some care about that. > >> Ok, no reason to use that many agcount but giving a "mkfs.xfs: pwrite64 >> failed: No space left on device" error for me stills seems a bug. > > The definition of a software bug stipulates incorrect or unexpected > program behavior. Error messages aren't bugs unless the wrong error > message is returned for a given fault condition, or no error is returned > when one should be. > > Are you stipulating that the above isn't the correct error message for > the fault condition? Or do you simply not understand the error message? > If the latter, maybe you should simply ask what that error means before > saying the error message is a bug. :) > > -- > Stan > > _______________________________________________ > xfs mailing list > xfs@xxxxxxxxxxx > http://oss.sgi.com/mailman/listinfo/xfs > _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
