Re: Disk Groups/Storage Management for a Large Database in PostgreSQL

Hi Amit,

El lun, 22 ene 2024 18:44, Amit Sharma <amitpgsql(at)gmail(dot)com> escribió:

> Hi,
>
> We are building new VMs for PostgreSQL v15 on RHEL 8.x For a large
> database of 15TB-20TB.
>
> I would like to know from the experts that is it a good idea to create
> LVMs to manage storage for the database?
>
> Or are there any other better options/tools for disk groups in PostgreSQL,
> similar to ASM in Oracle?
>
> Thanks
> Amit
>

Simple question that requires a somewhat more complex answer. There are
actually 3 metrics to consider:

1) Capacity
Your database doesn't fit on a single disk, so you need to distribute your
data across several disks. LVM would indeed be an option (as well as ZFS or
RAID disk arrays)

2) Safety
If you loose 1 disk, your data is at risk, as you're likely to loose all
tables partially loaded on that disk. LVM is still an option as long as it
is configured on a RAID array. ZFS can do that natively.

3) Performance
Oracle ADM ensures performance by automatically controlling the
distribution of the tables. I would need to see on a real case how it is
actually done. For sure, LVM and ZFS won't have this type of granularity.

On the other hand, you can distribute your data in table partitions to help
this distribution. It is not automatic but will surely help you to
distribute your workload.

Hope it helps
Olivier

>