All we need is an easy explanation of the problem, so here it is.
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 ?
How to solve :
I know you bored from this bug, So we are here to help you! Take a deep breath and look at the explanation of your problem. We have many solutions to this problem, But we recommend you to use the first method because it is tested & true method that will 100% work for you.
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.
Note: Use and implement method 1 because this method fully tested our system.
Thank you 🙂