On Wed, Jul 31, 2013 at 04:34:16PM -0400, Nathan Scott wrote: > ----- Original Message ----- > > In SGI's ICE product we have a script that uses pcp to gather quota > > information to feed to ganglia and to alert the admin if a project is > > over quota. With newer pcp where pmcd is run as user pcp and not as > > root we get failures to obtain the quota information. Changing back > > to root or other similar techniques works (as expected). Since the > > hosts that run this are cluster infrastructure nodes this may be the > > hack we decide on but we'd like other suggestions. > > [ http://oss.sgi.com/bugzilla/show_bug.cgi?id=985 ] > > Hmm, interesting - sorry about that, its unintended fallout and it did > not occur to me that the XFS quota metrics would be affected. I would > strongly recommend not going back to running pmcd as root, kittens will > surely die (although it is likely to be your only solution currently). > > There is a better way we can tackle this - we should isolate those > parts that need to run as root, and run them that way. This means we > need to transition these quota metrics into a new PMDA which runs as > root, separately to pmcd. > > In a quirky twist, I happened to come across a very similar problem > recently with the xfs.control.reset metric - this needs root access > too in order to function (it provides a reset-stats-back-to-zero > mechanism by writing to a procfs file), so it also was an unintended > victim of the unprivileged-pmcd changes. > > Thus, I propose we abstract out the xfs.* and quota.* (which, despite > being generically named "quota" metrics, are all XFS-specific) into a > new pmdaxfs which we run as root, in exactly the same way pmdaproc is > now run as root. We will need to manage the PMID transition (domain > number on these metrics will change) via pmlogrewrite, but that is a > well-trod path now and happily pmdaproc is an existence-proof that we > can successfully make these transitions. > > If we do it correctly, we should be able to do this transparently so > that nobody notices. However, Murphy being Murphy ... I've CC'd the > XFS list to let 'em know this is coming. Thanks Nathan, we'll keep an eye out. _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
