Re: ZFS filesystem - supported ?

On 2021-10-24 06:48, Mladen Gogala wrote:

> On 10/23/21 09:37, Laura Smith wrote:
>
>> Hi Mladen,
>>
>> Yes indeed, snapshots is the primary reason, closely followed by
>> zfssend/receive.
>>
>> I'm no stranger to using LVM snapshots with ext4/xfs but it requires a
>> custom shell script to manage the whole process around backups. I
>> feel the whole thing could well be a lot cleaner with zfs.
>>
>> Thank you for the links, I will take a look.
>>
>> Laura
>
> Yes, ZFS is extremely convenient. It's a volume manager and a file
> system, all rolled into one, with some additiional convenient tools.
> However, performance is a major concern. If your application is OLTP,
> ZFS might be a tad too slow for your performance requirements. On the
> other hand, snapshots can save you a lot of time with backups,
> especially if you have some commercial backup capable of multiple
> readers. If your application is OLTP, ZFS might be a tad too slow for
> your performance requirements. The only way to find out is to test. The
> ideal tool for testing is pgio:
>
> https://kevinclosson.net/2019/09/21/announcing-pgio-the-slob-method-for-postgresql-is-released-under-apache-2-0-and-available-at-github/
>
> For those who do not know, Kevin Closson was the technical architect
> who has built both Exadata and EMC XTRemIO. He is now the principal
> engineer of the Amazon RDS. This part is intended only for those who
> would tell him that "Oracle has it is not good enough" if he ever
> decided to post here.

Interesting subject... I'm working on a migration from PG 9.2 to PG 14
and was wondering which File System should I use. Looking at this
thread, looks like I should keep using ext4.

I don't know where you have your database deployed, but in my case is in
AWS EC2 instances. The way I handle backups is at the block storage
level, performing EBS snapshots.

This has proven to work very well for me. I had to restore a few backups
already and it always worked. The bad part is that I need to stop the
database before performing the Snapshot, for data integrity, so that
means that I have a hot-standby server only for these snapshots.

Lucas