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From Yuki Morishita <mor.y...@gmail.com>
Subject Re: Nodetool clearsnapshot
Date Tue, 13 Jan 2015 14:59:31 GMT
Snapshot during repair is automatically cleared if repair succeeds.
Unfortunately, you have to delete it manually if repair failed or stalled.

On Tue, Jan 13, 2015 at 8:30 AM, Batranut Bogdan <batranub@yahoo.com> wrote:
> OK Thanks,
>
> But I also read that repair will take a snapshot. Due to the fact that I
> have Replication factor 3 for my keyspace, I run nodetool clearsnapshot to
> keep disk space use to a minimum. Will this impact my repair?
>
>
> On Tuesday, January 13, 2015 4:19 PM, Jan Kesten <j.kesten@enercast.de>
> wrote:
>
>
> Hi,
>
> I have read that snapshots are basicaly symlinks and they do not take that
> much space.
> Why if I run nodetool clearsnapshot it frees a lot of space? I am seeing GBs
> freed...
>
>
> both together makes sense. Creating a snaphot just creates links for all
> files unter the snapshot directory. This is very fast and takes no space.
> But those links are hard links, not symbolic ones.
>
> After a while your running cluster will compact some of its sstables and
> writing it to a new one as deleting the old ones. Now for example you had
> SSTable1..4 and a snapshot with the links to those four after compaction you
> will have one active SSTable5 which is newly written and consumes space. The
> snapshot-linked ones are still there, still consuming their space. Only when
> this snapshot is cleared you get your disk space back.
>
> HTH,
> Jan
>
>
>
>



-- 
Yuki Morishita
 t:yukim (http://twitter.com/yukim)

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