Backup copy IOPS (type + count)

[cividan]

Hi, I'm looking at information on backup copy job, we want to use backup copy to send backup to a different bacupk storage pool. How does retention work for backup copy job and what type of IOPS are done when doing backup copy job. The storage we plan to use has only NLSAS drive which are very bad at random I/O so it's not good enough for regular backup but we would like to be able to use it for backup copy job but I didn't find any information on these 2 questions.

Any info or link would be appreciated.

[Shestakov]

Hi,
Backup copy uses forever forward incremental method, which means it merges full backup with the latest increment each time a new increment created. And yes merge is a heavy random I/O process.
Thanks!

[foggy]

However, you could avoid the merge process by enabling backup copy active fulls. This will effectively switch it to a simple forward incremental mode with sequential writes on the target storage.

[cividan]

We do not want the backup copy job to touch the Live production VM to do active full as this would take too long and would mess with the daily backup job.

We're using reverse incremental on our "main backup storage" with a retention settings of 7 version (daily), We want to create backup copy job (weekly) to this "slow speed storage" with a retention of only 4 version.

Question #1: Can we specify different retention setting for backup job and backup copy job?

Question #2: Can we tell the "backup copy job" to always copy the latest full from the "main backup storage" and never do incremental so that it doesn't have to deal with merge and random IO?

With this setting in mind, the "slow speed storage" would always do sequential write and simply remove the oldest full backup when expiration occur. I'm far from beeing an expert in storage IO so maybe what I'm impliing will be sequeltial IO will actually not be the case and if so please please enlighten me.

[cividan]

However, you could avoid the merge process by enabling backup copy active fulls. This will effectively switch it to a simple forward incremental mode with sequential writes on the target storage.

Meaculpa, I had not read the whole link before replying. This seem to be exactly what we need and even better. Thanks!

[Shestakov]

Correct,
Backup copy Active Full doesn`t touch the VM.
Thanks!

[foggy]

Question #1: Can we specify different retention setting for backup job and backup copy job?

Yes.

Question #2: Can we tell the "backup copy job" to always copy the latest full from the "main backup storage" and never do incremental so that it doesn't have to deal with merge and random IO?

No need to copy full each time, after switching to active fulls, backup copy will produce increments between fulls without merge, just as the forward incremental backup job does.