Truncate needs no space. It just creates a hard link of all affected SSTables under the corresponding -SNAPSHOT dir (at least with default settings) and then removes the SSTables. Also this operation should be rather fast as it is mostly a file-deletion process with some metadata updates.
2017-04-21 11:21 GMT+02:00 Kunal Gangakhedkar <kgangakhed...@gmail.com>: > Hi all, > > We have a CF that's grown too large - it's not getting actively used in > the app right now. > The on-disk size of the <ks>.<cf> directory is ~407GB and I have only > ~40GB free left on the disk. > > I understand that if I trigger a TRUNCATE on this CF, cassandra will try > to take snapshot. > My question: > Is the ~40GB enough to safely truncate this table? > > I will manually remove the <ks>.<cf> directory once the truncate is > completed. > > Also, while browsing through earlier msgs regarding truncate, I noticed > that it's possible to get OperationTimedOut > <http://www.mail-archive.com/user@cassandra.apache.org/msg48958.html> > exception. Does that stop the truncate operation? > > Is there any other safe way to clean up the CF? > > Thanks, > Kunal >
