In the "worst" case, compaction combines them all into a single file anyway. So I think your approach is flawed. It's designed to allow adding capacity by adding nodes, not just by adding more space, or your cpu / ram ratio will degrade.
On Thu, Feb 25, 2010 at 2:48 PM, Anthony Molinaro <antho...@alumni.caltech.edu> wrote: > Okay, so the disk sizing seems to make sense for what I am seeing, the > disk which seems to get all the data is the largest. On the new machines > which have 3 disks of equal size, compaction seems to be distributing > among the disks. > > Raid0 would sort of defeat the purpose of being able to add additional > capacity on the fly (ie, adding ebs volumes to increase capacity), as > I need to know ahead of time what my configuration is. > > The new boxes ended up with all the data files in one directory because > of the bug in 0.5.0 when bootstrapping with multiple directories which > I worked around by using one directory, bootstrapping, then adding > the other directories. > > So when I have the situation of I just added an additional directory > with space equal to a current directory, is there any way to redistribute > the data files? The operations page makes me think that maybe nodeprobe > repair might do it, will it? > > Thanks, > > -Anthony > > On Thu, Feb 25, 2010 at 01:43:22PM -0600, Jonathan Ellis wrote: >> Compaction is why http://wiki.apache.org/cassandra/CassandraHardware >> recommends raid0-ing if you are concerned about free disk space >> limits. >> >> On Thu, Feb 25, 2010 at 1:36 PM, Gary Dusbabek <gdusba...@gmail.com> wrote: >> > Cassandra always compacts to the directory with the most free space. >> > There is not a way to influence this. >> > >> > Gary >> > >> > On Thu, Feb 25, 2010 at 13:23, Anthony Molinaro >> > <antho...@alumni.caltech.edu> wrote: >> >> Hi, >> >> >> >> So is there anyway to force distribution among DataFileDirectory entries >> >> when you add a new one? Looking at the nodeprobe operations it seems like >> >> repair which causes a major compaction might do it? I've tried shutting a >> >> node down moving files around by hand and starting up, but the next >> >> compaction seems to move everything back to a single directory? >> >> >> >> I do see files show up in other directories as they are flushed, but >> >> then they all seem to make their way back to the first directory in the >> >> list. >> >> >> >> Thanks, >> >> >> >> -Anthony >> >> >> >> -- >> >> ------------------------------------------------------------------------ >> >> Anthony Molinaro <antho...@alumni.caltech.edu> >> >> >> > > > -- > ------------------------------------------------------------------------ > Anthony Molinaro <antho...@alumni.caltech.edu> >
