RE: Verify or dump pgdata files

[Murthy Nunna <mnunna@xxxxxxxx>]

Hi Muhammad,

 

Thank you for responding to my query.

 

I don’t think checksum method will work in my situation because the source file would have changed by the time I run checksum. So, the checksum (or diff) will be different.

I am doing rsync of active cluster.

 

What I am looking for is physical (structural) verification of target file such as beginning block and end block, beginning of file and end of file etc. All I want to know is “completeness” and “readability” of the file by postgres.

 

Thanks.

 

 

From: Muhammad Ikram <me.mikram@xxxxxxxxx>
Sent: Sunday, October 20, 2024 10:34 PM
To: Murthy Nunna <mnunna@xxxxxxxx>
Cc: pgsql-admin@xxxxxxxxxxxxxx
Subject: Re: Verify or dump pgdata files

 

[EXTERNAL] – This message is from an external sender

Hi,

 

Could you use diff ? e.g.

 

diff -qr /var/lib/pgsql/15/data /tmp/data

 

Or

 

pg_checksums --verify --data-dir=/pgdata  (for checksum enabled databases)

 

or do checksum on source and target and take diff between two checksum generated files e.g.

 

cd /pgdata
find . -type f -exec sha256sum {} \; > /tmp/source_checksums.txt

 

 

Regards,

Ikram

 

 

 

On Sun, Oct 20, 2024 at 4:45 AM Murthy Nunna <mnunna@xxxxxxxx> wrote:

Hi,

 

We are currently using pg_waldump to verify integrity of WAL files after archiving them in external storage. If the WAL is incomplete pg_waldump returns error, which is great.

 

Similarly, I am wondering if there is any utility that can be used against data files in /pgdata. Just to verify after “rsync” of /pgdata.

 

Thanks in advance for your response.