Re: Methods to quickly spin up copies of an existing databases

Kenneth Marshall <ktm@rice.edu> writes:

> On Fri, Mar 01, 2019 at 11:57:30AM -0800, Kevin Wilkinson wrote:
>
>> if you are able/willing to use ZFS (rather than ext4, xfs, ...) to
>> store your database, then it might work for you. ZFS is
>> copy-on-write so it can very quickly clone a database.
>> 
>> kevin
>
> Hi Arjun
>
> Redhat 7 does have LVM snapshots that does something similar. Kevin is
> correct, COW is the secret.

Going a bit further...

Any sort of storage backend that can support *atomic* snapshots across
*all* volumes (in case multiple tablespaces ar involved), can be used to
permit $instantaneous cloning where instantaneous relates to the actual
snapshot time and crash recovery.

Inability to make *atomic* snaps but perhaps seperate snaps very
quickly, combined with PITR can result in clones of high-churn systems
sized in TBs (as in our use case) to be provisioned in about 1 minute.

Nothing but the most trivial system can be cloned rapidly and perhaps
any number of times in succession without employment of
thin-provisioning, copy-on-write (as mentioned already), etc.

                   Virtual copy is more and more compelling as physical
                   size, or more precisely, *physical* copy time grow.

HTH



>
> Regards,
> Ken
>
>

-- 
Jerry Sievers
Postgres DBA/Development Consulting
e: postgres.consulting@comcast.net