Veeam backup & copy job storage IO

[stewsie]

Hi

We are starting to look at a replacement storage array and with our existing array have suffered with the merge operation in particular being IO intensive. I had been given information before about the IO patterns for the merge but cannot find it. Does anyone have any information on this? I think it was the number of reads and writes for the merge that was important.

Thanks

[Mildur]

Merge Process is normally a "Forward incremental, synthetic full":


https://bp.veeam.com/vbr/VBP/4_Operatio ... thods.html

Method I/O impact on destination storage

• Forward incremental 1 x write I/O for incremental backup size

• Forward incremental, active full 1 x write I/O for total full backup size

• Forward incremental, transform 2 x I/O (1x read, 1x write) for incremental backup size

• Forward incremental, synthetic full 2 x I/O (1x read, 1x write) for entire backup chain

• Reversed incremental 3 x I/O (1x read, 2x write) for incremental backup size

• Synthetic full with transform to rollbacks 4 x I/O (2x read, 2x write) for entire backup chain

[stewsie]

Excellent. Thank you

[Andreas Neufert]

The table above need extra background information as you have to combine the IOs

Synthtic Full + Incremental
Daily
=> Near Sequential Write per 1MB source change rate equals 1 IO + overall some metadata updates (additional 2% IOs)
SF day
=> Near Sequential Write per 1MB source change rate + some metadata updates additional 2% IOs)
=> For 100% of the source data devided by 1MB is the number of random read (1 IO per 1MB) + near sequential write 1IO per 1MB + some metadata updates additional 5% IOs)

Forever Forward Incremental
Daily
=> Near Sequential Write per 1MB source change rate equals 1 IO + overall some metadata updates additional 2% IOs)
=> Add the same amount additionally with sequential read
=> Add the same amount additionally for random write processing + overall some metadata updates additional 2% IOs)

It is important to mention Veeams IO operation works on 1MB level while the storage works usually on a lower block size. Please use the tools from the vendors with the Veeam input.