From: Laurenz Albe <laurenz.albe@cybertec.at>
To: Ron Johnson <ronljohnsonjr@gmail.com>
To: Pgsql-admin <pgsql-admin@lists.postgresql.org>
Subject: Re: Would you ever recommend Shared Disk Failover for HA?
Date: Fri, 23 Feb 2024 10:08:14 +0100
Message-ID: <fa2bd3bec91dcf0c206931a3cfc0f31a46a6ea44.camel@cybertec.at> (raw)
In-Reply-To: <CANzqJaAUrKfvWgi4tEPgu2r4RPvbNW2HKy8jhA1v5i=8R6DqQg@mail.gmail.com>
References: <20240222185937.M23609@ibu.de>
<32d1035973ed0c7be36a419df1246f94efae3166.camel@cybertec.at>
<CANzqJaAUrKfvWgi4tEPgu2r4RPvbNW2HKy8jhA1v5i=8R6DqQg@mail.gmail.com>
On Fri, 2024-02-23 at 02:21 -0500, Ron Johnson wrote:
> On Fri, Feb 23, 2024 at 2:02 AM Laurenz Albe <laurenz.albe@cybertec.at> wrote:
> [snip]
> >
> > Anyway, my personal experience with a shared disk setup is a bad one.
> >
> > Imagine two nodes, redundantly attached to disks mirrored across data
> > centers with fibrechannel. No single point of failure, right?
> > Well, one day one of the fibrechannel cables had intermittent failures,
> > which led to a corrupted file system.
> > So we ended up with a currupted file system, nicely mirrored across
> > data centers. We had to restore the 3TB database from backup.
>
> 1. Sounds like both nodes were turned on.
Possible, but I think that's not relevant.
> 2. Couldn't this happen in /any/ SAN with redundant cabling?
I'd say yes, and the redundant cabling is irrelevant too - I just
wanted to emphasize that hardware redundancy is not enough.
The single point of failure was the file system.
Yours,
Laurenz Albe
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Reply to all the recipients using the --to and --cc options:
reply via email
To: pgsql-admin@postgresql.org
Cc: laurenz.albe@cybertec.at, ronljohnsonjr@gmail.com, pgsql-admin@lists.postgresql.org
Subject: Re: Would you ever recommend Shared Disk Failover for HA?
In-Reply-To: <fa2bd3bec91dcf0c206931a3cfc0f31a46a6ea44.camel@cybertec.at>
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
This inbox is served by DDX for PostgreSQL; see mirroring instructions
for how to clone and mirror all data and code used for this inbox