[Gluster-users] Tiered Volumes and Backups

Lindsay Mathieson lindsay.mathieson at gmail.com
Mon Aug 8 20:58:39 UTC 2016


On 9/08/2016 12:01 AM, Dan Lambright wrote:
> By default, files are marked for promotion on the first I/O. So if you did a backup and touched every file, they would all be marked for promotion. You ought to be able to change that, so only files touched some number of times (2X?) are promoted. See the "cluster.write-freq-threshold" setting below.

Wouldn't it be cluster.read-freq-threshold? the backup reads the files 
on the vol, and writes the backup elsewhere.

>
> What size files are you using? The way things work (right now), the smaller the file, the less benefit you will see... the cost of metadata round trips (LOOKUPS) start to exceed faster data transfers from SSDs.

Very interesting - all my files are shards of 64MB size (or less). My 
initial test of tiering has atrocious performance.

-- 
Lindsay Mathieson



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