Based on Eric's email, it sounds like EBS is a no go from the start. But given your snapshot feedback, it seems like you have to plan on leaving slack on every disk, and the % of slack depends on the size of a snapshot relative to the data (given the snapshot shares the disk with the data, at least temporarily).
will On Wed, Mar 9, 2011 at 11:59 AM, Sasha Dolgy <sdo...@gmail.com> wrote: > Hi will, > > Quickly did a snapshot: > > nodetool -h 10.0.0.2 -p 8080 snapshot 09032011 > > The snapshots end up in the data dir for cassandra. The default is > /var/lib/cassandra/data/<keyspace>/snapshots/ > > In this directory i have: 1299689801925-09032011 > > -sd > > > On Wed, Mar 9, 2011 at 5:54 PM, William Oberman > <ober...@civicscience.com>wrote: > >> I haven't done backups yet, so I don't know where the data is written. Is >> it where the nodetool is run from? Or local to the instance running >> cassandra (and there, local to the data directory?). I assumed it was the >> latter (not finding docs on that yet), and that would require 2x storage >> allocated on that instance for 1x data (to have room for the snapshot). If >> its the former, then yes, I'd totally run the command from an ephemeral >> store, and backup to S3. >> >> will >> >> >> On Wed, Mar 9, 2011 at 11:48 AM, Sasha Dolgy <sdo...@gmail.com> wrote: >> >>> Hi Will, >>> >>> http://wiki.apache.org/cassandra/Operations#Backing_up_data >>> >>> <http://wiki.apache.org/cassandra/Operations#Backing_up_data>If the >>> snapshot is written to the ephemeral storage ... there isn't a cost. (i need >>> to confirm that) >>> >>> You can then move this to an S3 bucket with RDS if you want or full >>> 99.999999999% redundancy and have it available to developers >>> >>> This is what I had in my head.... >>> -sd >>> >>> >>> On Wed, Mar 9, 2011 at 5:39 PM, William Oberman < >>> ober...@civicscience.com> wrote: >>> >>>> I thought nodetool snapshot writes the snapshot locally, requiring 2x of >>>> expensive storage allocation 24x7 (vs. cheap storage allocation of a ebs >>>> snapshot). By that I mean EBS allocation is GB allocated per month costs >>>> at >>>> one rate, and EBS snapshots are delta compressed copies to S3. >>>> >>>> Can you point the snapshot to an external filesystem? >>>> >>>> will >>>> >>>> >> >> >> -- >> Will Oberman >> Civic Science, Inc. >> 3030 Penn Avenue., First Floor >> Pittsburgh, PA 15201 >> (M) 412-480-7835 >> (E) ober...@civicscience.com >> > > > > -- > Sasha Dolgy > sasha.do...@gmail.com > -- Will Oberman Civic Science, Inc. 3030 Penn Avenue., First Floor Pittsburgh, PA 15201 (M) 412-480-7835 (E) ober...@civicscience.com
