Disk partitioning for Red Hat installation

DCIM_Support · ‎2020-07-05

Hi Team!

I need your advice about disk partitioning when we need to install DCO on Red Hat.

As per manual disk space should be parted like this:

/data is used for indexes and ETL configuration. Minimum size 5 GB.
/data/backup is used for backups. Minimum size 50 GB. Backups should always be mounted on a remote network share.
/opt/jboss-as is used for the application server. Minimum size 10 GB.
/var/lib/pgsql is used for the postgres database. Minimum size 30 GB.
/var/log is used for log files. Minimum size 5 GB.

Total size is 100 Gb.

How I need to change this disk space in case I have 400 Gb disk?

Should I expand all disks propotionally or I need expand only /var/lib/pgsql for example?

What is the best practice? Please advice.

DCIM_Support · ‎2020-07-05

Hello Valentin.

Did you use logical volume manager when the above partition layout was created? This decision is made when the CentOS or Redhat host is installed.

If yes, then expanding filesystems at a later time is possible. If not, then its less likely you'll be able to expand the filesystems without having to re-install DCO on a server with the modified partition layout.

Regards

Greg Sterling

See Answer In Context

DCIM_Support · ‎2020-07-05

Hello Valentin.

Did you use logical volume manager when the above partition layout was created? This decision is made when the CentOS or Redhat host is installed.

If yes, then expanding filesystems at a later time is possible. If not, then its less likely you'll be able to expand the filesystems without having to re-install DCO on a server with the modified partition layout.

Regards

Greg Sterling

DCIM_Support · ‎2020-07-05

Hi Greg!

Thanks for your answer!

My question is about initial DCO installation from scratch.

What I should say to customer's Linux administrator about disk size?

I'm worry about useful resource usage and afraid situations when we have too much space for ETL and not enough space for DB, for example.

Playing with filesystem on production server is not best option I guess. As well as re-install because of initial mistake.

DCIM_Support · ‎2020-07-05

I don't think there is an official "best practice" here as the requirements are sometimes dictated by the customers operating systems policies.

You are correct the user guide makes the following recommendations:

/data is used for indexes and ETL configuration. Minimum size 5 GB.
/data/backup is used for backups. Minimum size 50 GB. Backups should always be mounted on a remote network share.
/opt/jboss-as is used for the application server. Minimum size 10 GB.
/var/lib/pgsql is used for the postgres database. Minimum size 30 GB.
/var/log is used for log files. Minimum size 5 GB.

That being said, if I run a default installation of DCO on CentOS using our iso you'll end up with something like this:

/boot is 500MB
/boot/efi about 200MB
swap about 512MB (may change based on the size of the disk)
/ will own the rest of the disk space

In the above default layout the customer is not defining specific partitions for /opt/jboss-as, and /var/lib/pgsql and so on. In this case if you define a 400GB disk, most of the disk space would remain on the / filesystem and would be available to all of the directories mentioned in the user guide.

There are a couple of reasons to consider defining specific partitions.

One would be to protect the app or operating system if a partition becomes full. If the /data partition was full, DCO will have issues but the operating system would continue to run.
The other could be performance related if the customer was to choose to separate disk IO's, they could allocate separate disks from an array as the source of the above partitions. So the disk IO's to the /var/lib/pgsql folder would be separated from the disk IO's to the other folders.

If deployed as one disk with the above directories all under the / filesystem, then DCO, Postgres, and the operating system are all sharing/accessing the same disk.

I have worked with customers which require the partitions be split out, others not.

I can tell you the /var/lib/pgsql directory has the postgres database on it so it will grow as your customers configuration grows. /data/backup is the default location for DCO backup files, so if the solution is large this directory could consume a lot of disk space, so make sure if needed you define a cleanup policy in the backups settings in the web client. /var/log contains OS log files and some postgres/dco logs, but most of the dco logs are under /opt/jboss-as

Hope this helps

GregS

DCIM_Support · ‎2020-07-05

Thank you very much!

DCIM_Support · ‎2020-07-05

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