Am Sonntag, 5. August 2012 schrieb Stefan Priebe: > Am 05.08.2012 um 00:43 schrieb Dave Chinner <david@xxxxxxxxxxxxx>: > > On Tue, Jul 31, 2012 at 03:56:54PM +0200, Stefan Priebe - Profihost AG wrote: > >> Hello list, > >> > >> i'm planning to create a couple of VMs with just 30GB of space while > >> using xfs as the main filesystem. > >> > >> Now i alreay know that some of the VMs will grow up to 250GB while > >> resizing the block device and using xfs_growfs. > > > > Just use thin provisioning and make it 250GB to begin with. Thin > > provisioning mades filsystem grow/shrink pretty much redundant.... > > But dm thin isn't stable isn't it? Does xfs reallocate used parts of > the block Device before using new parts? Otherwise deleting and > recreating files will result in full used space pretty fast. A periodic fstrim might help if the TRIM/DISCARD is supported in all layers. And whether it is is a good question that depends on well where your data is stored and what layers in the kernel are involved in storing it and the kernel version of course. > >> Is it a problem if this grow will happen in small portions (30GB => > >> 50GB => 75GB => 100GB => ... 300GB)? > > > > Growing a filesystem by an order of magnitude is the limit of what > > I'd suggest is sane. Growing it by two orders of magnitude > > (espcially if you start with a 16 AG filesystem because of stripe > > alignment) is going to cause problems with the number of AGs and > > the subsequent freespace management scale issue.... > > I would start with ag=4 and end up in ag 48 in my tests. Thats IMHO quite much for upto 500 GiB. But it still depends on what kind of storage this is located. -- Martin 'Helios' Steigerwald - http://www.Lichtvoll.de GPG: 03B0 0D6C 0040 0710 4AFA B82F 991B EAAC A599 84C7 _______________________________________________ xfs mailing list xfs@xxxxxxxxxxx http://oss.sgi.com/mailman/listinfo/xfs
