IBM DB2 database backup speed

Question

I have a IBM DB2 database on LUW that is around 5TB. Currently the backup of 5TB takes around 24 hours.

I am thinking of creating a mountpoint called /dbbackup and that mount point is a LVM powered by 4 SSD Disks and the write speed of SSD is 500Mbps would it be fair to assume that my DB will be backed up in 1 Hour ?

i.e 5242880 / (500 * 4) ?

Is my back of the envelope calculations correct ? Should I instead use say HDD's with 200Mbps write bandwidth ?

• Lennart - Slava Ukraini: How much is changed in the database each day? You might want to have a look at incremental delta backups and take a full backup every week or even month. See ibm.com/docs/en/db2/… as a starter

Answer 1

Disk speed is just one of the variables in the equation. You'll need to factor in the file system overhead, the degree of parallelism the backup utility can handle and its own processing cost, the extra work by the database encryption or compression, if used, and the concurrent activities on the database server.

So, no, it will not be backed up in one hour. How long it will take in reality, only tests can tell.

I know you didn't ask for this, but consider delta and/or tablespace-level backups.

• jhon.smith: Thanks for taking timeout and taking a look at this question. Assuming I only have 1 tablespace and i do db2 backup mydb to /dbbackup /dbbackup /dbbackup /dbbackup do you think there will be any benefit at all ?