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Disk Storage Unit - Maximum Concurrent Jobs

Level 4
I have 2 10TB sata arrays configured as storage units. What is everyone else doing in this situation? or in any similar situations regarding maximum concurrent jobs? Is there a formula to figure out the best possible config.?

Level 6
you need to work out what sustained throughput you will get when reading, writing, and read/writing, as this will influence how many streams you run concurrenty, and also how many you want to run when you are staging or destaging to tape.

I would say the other thing you need to consider with the size of the LUNs is the possible issues with fragmentation...

Level 6
h m has it here...
This is how we figure it out in general for ours.

1) Use a tool to figure out your max write on the LUN (if it is SATA, it is likely 150MB/s)
You can use some tools to figure this out such has HDSpeed on windows. This will depend on the type of array etc.
2) Figure out the backup throughput of your clients. This vary's widly... what we have found is that our windows filesystems average about 5-10MB/s. But things like SQL and Exchange can go all the way up to 50-70MB/sec.
3) Like h m said, to address fragementation, we typically split up the large LUNS. We have one 6TB that we split into 3-2TB volumes. That LUN can sustain about 90MB/s writes so we basically have about 30MB/sec/volume, so we limit to 3-4 streams. Except for exchange which we only do 1 stream.