Date: Fri, 10 Apr 2020 17:01:54 -0400
From: Bruce Momjian <bruce@momjian.us>
To: Erik Brandsberg <erik@heimdalldata.com>
Cc: Lu Dillon <ludi_1981@hotmail.com>,
	Iuri Sampaio <iuri.sampaio@gmail.com>,
	Ed Behn <ed.behn@collins.com>, MichaelDBA <MichaelDBA@sqlexec.com>,
	Steve Midgley <science@misuse.org>,
	"pgsql-sql@lists.postgresql.org" <pgsql-sql@lists.postgresql.org>
Subject: Re: =?utf-8?B?5Zue5aSN?= =?utf-8?Q?=3A?= [External] Re: Separate
 volumes
Message-ID: <20200410210154.GC24987@momjian.us>
References: 
 <CAE1kc7VfQVz0VGf4cyjaY5KYSZxrPQjPWMoEsqFTJ41-LkMOHg@mail.gmail.com>
 <CAFcck8FF4T3_PL7Fa+iW5YBkA4iZ3aR2V_jka=GpV9taPph9NQ@mail.gmail.com>
 <CAJexoSLSHRVOKzVGD-pDHE=KY9un7bPsxGO6fSKZVgeGsj2t6g@mail.gmail.com>
 <5b60ae44-33e0-d9ea-d6e9-c6db9b4c7ef1@sqlexec.com>
 <CAE1kc7W=OtwRutn+4p1ShMk+koyvv8W0JunSLiV5wMdL0OVZTw@mail.gmail.com>
 <399454FC-D175-421C-AC3A-31B1082E7881@gmail.com>
 <HK2PR02MB4227F498470D5CC93158DF1385C30@HK2PR02MB4227.apcprd02.prod.outlook.com>
 <20200410200420.GA24987@momjian.us>
 <CAFcck8H1JfBE1sM98y1C+=Qfay4DayO-_gE_5hcjpX3_r4BmzQ@mail.gmail.com>
MIME-Version: 1.0
Content-Type: text/plain; charset=iso-8859-1
Content-Disposition: inline
Content-Transfer-Encoding: 8bit
In-Reply-To: 
 <CAFcck8H1JfBE1sM98y1C+=Qfay4DayO-_gE_5hcjpX3_r4BmzQ@mail.gmail.com>
User-Agent: Mutt/1.10.1 (2018-07-13)
Precedence: bulk

On Fri, Apr 10, 2020 at 04:52:06PM -0400, Erik Brandsberg wrote:
> A modern filesystem can help avoid even this complexity.  As an example, I am
> managing one PG setup that is self-hosted on an AWS EC2 instance, with 16TB of
> raw storage.  The bulk of that storage is in ST1, or the cheapest rotating disk
> capacity available in EBS, but is using ZFS as the filesystem (with
> compression, so realistically about 35TB of raw data).  The instance type is a
> Z1d.metal, which has two 900GB NVME drives, which have been divided to provide
> swap space, as well as ZFS read and write caching.  This setup has largely
> offset the slow performance of the st1 disks, and kept the performance usable
> (most of the data is legacy, and rarely used).   I'm a big fan of keeping the
> DB configuration simple, as it is way too easy to overlook tuning of a
> filespace for an index, causing performance problems, while if you keep it
> auto-tuning at the filesystem level, it "just works".

You are saying the cloud automatically moves data between the fast and
slow storage?  I know many NAS systems do this, but I have also seen
problems when NAS systems guess wrong.

-- 
  Bruce Momjian  <bruce@momjian.us>        https://momjian.us
  EnterpriseDB                             https://enterprisedb.com

+ As you are, so once was I.  As I am, so you will be. +
+                      Ancient Roman grave inscription +