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Paths to disks: Is it a limited resource???

Fred2010
Level 6

Hi all,

I have a question about using multipathing disks on a 5230

Our setup is that we have several 5230 appliances, which are zoned to our 3PAR storage arrays in order to access our VMware disks for making (accelerated) VM backups

Currently, our Netbackup appliances are only zoned to just a few storage ports of our 3PAR arrays, whilst it has many more storrage processor ports available.

As only a few ports are zoned and seen by our 5230 appliances now, all data has to be moved to the NBU units, using the paths it has visible, which causes congestion on those ports.

My question:

I can extend the number of paths to the 3par storage processor ports to 16 possible paths in total per appliance, which means each disk that we export to the NBU appliances is now visible via 16 different paths. We have quite a large number of disks to export in total, so the number of disks * 16 paths becomes quite a dizzying amount of total paths...

Is this number of paths a limited resource within the netbackup appliances? Can I go ahead and zone all storage ports of all our 3PAR arrays (We have 6) and export all luns/disks (many) over 16 paths, without it causing issues?

Any help/input is appreciated!

Thanks

4 REPLIES 4

sdo
Level 6
Partner    VIP    Certified

Yes, is a limited resource.

I would have thought that your limit will be the same as the ESXi host limits, because VADP style backups use VDDK.

The limit is 1024 paths:

https://kb.vmware.com/selfservice/microsites/search.do?language=en_US&cmd=displayKC&externalId=1020654

Marianne
Moderator
Moderator
Partner    VIP    Accredited Certified

You forgot to tell us which Appliance version?

It seems that multipathing for SAN LUNs is supported as from 2.6.0.2. 
NetBackup Appliances 2.6.0.2 is now available!

Fred2010
Level 6

Hi SDO, Marianne,

Sorry for reacting so late: We are running a mix of 2.6.1.1 and 2.6.1.2 (Migrating to 2.7.2 soon)

Thank you for your information, but I am still unclear:

Is the number 1024 you mention per system or per disk?

My question was mainly about disk paths:

When I zone my appliance to the storage array using a total of 16 possible paths, all disks are 'seen' 16 times. Can I only have 1024 / 16 = 64 disks then?

Thanks for clarifying :)

 

 

 

sdo
Level 6
Partner    VIP    Certified

yes

so, if you were to use only eight paths per "disk" then you could have 128 "disks"

but I think there's a disk limit too - you'll have to check that.