Note: "permalinks" may not be as permanent as we would like,
direct links of old sources may well be a few messages off.
On 01/29/2016 11:08 AM, Julien Escario wrote: > Le 25/01/2016 15:19, Julien Escario a écrit : >> So I'm wondering how and when 'pool free' value is calculated. Is it >> recalculated only when a new ressource is created ? deleted ? It is normally recalculated whenever drbdmanage changes something that modifies the amount of available space. Another problem is that any backend that uses thin allocation essentially returns data from fantasy land, so the pool free value in drbdmanage will never be anything better than a rough estimate. Actually allocating a volume of the reported free size might work or might not work, depending on how much actual storage ends up being allocated upon creating the resource on each node. Right now, DRBD still full-syncs (which will also change in the future, because obviously that does not make a lot of sense with thin allocation), and drbdmanage does not yet have lots of logic for estimating thin allocation, and for both reasons, all the values returned by drbdmanage as it is now are usually very conservative and fat-allocation-like regarding free space. >> Is there a way to force it to rescan free space ? (with a dbus command perhaps ?) >> >> That could perhaps be done by a cron job running at defined frequency ? We have a prototype of a daemon that does something like that (drbdmanage-poolmonitord). While update-pool always locks the control volumes and updates pool data, the daemon uses a monitoring function (the update_pool_check() D-Bus API) that first checks whether the amount of space has changed, and only if it did, it triggers the update-pool command. That will be released with some future release of drbdmanage, as it will be especially useful if a storage pool is shared by drbdmanage and other allocators. > > Best regards, > Julien Escario > Mit freundlichen Gruessen / Best regards, -- : Robert Altnoeder : Trainer / Developer : LINBIT | Your Way to High Availability : : http://www.linbit.com DRBD® and LINBIT® are registered trademarks of LINBIT.