HPE EVA Storage

Re: Adding more disks to existing disk groups

 
Ebk
Advisor

Adding more disks to existing disk groups

Hi

I need to add more disks into our existing disk groups.
I have attached the current setup and would like to know the recommandations to integrate the new disks.

I want to add 8 disks into the disk group 1 and 16 in the disk group 2.

Finally I would like to know what is the size limit for disk group?

Many thanks
9 REPLIES 9
IBaltay
Honored Contributor

Re: Adding more disks to existing disk groups

Hi,
a) the best practice is to add the new disks in the group of 8 to create the default new RSSes.
b) for the disk group sizing see the eva perf best practices:
ftp://ftp.compaq.com/pub/products/storageworks/whitepapers/5982-9140EN.pdf

one rack config is up to 168 disks
two rack config is up to 240 disks
so the best is to have as less DGs as possible:
e.g. 2x84 and 2x120 or 3x80, from the disk distribution point of view, the back end performance grows almost linearly till the count of 80 disks, ...
http://h10025.www1.hp.com/ewfrf/wc/document?docname=c00365744&cc=us&dlc=en&lc=en&jumpid=reg_R1002_USEN
the pain is one part of the reality
Víctor Cespón
Honored Contributor

Re: Adding more disks to existing disk groups

You currently have 12 disk enclosures, so it must be an EVA8000 or 8100. All the disks on each disk group are the same size.
A disk group can contain up to 240 disks (adding an expansion cabinet to the EVA with 6 more enclosures).
Add disks following column order, so they are distributed among all the enclosures.
so in this case you'll add 8 disks from column 5 to one group and the rest to the other.
Ebk
Advisor

Re: Adding more disks to existing disk groups

thanks for the reply.
Just one more question: Is there any advantage to start from bottom or the top?
I have reattched the planned work after reading the pdf and your recommandations.

Thanks again!
IBaltay
Honored Contributor

Re: Adding more disks to existing disk groups

that is ok, and to stay fully vertical in the RSS group
a) 8 in bay 5,
b) 4 bay in 5 and first 4 in bay 6
c) 8 in bay 6

Note
before the group add the disk physicaly into bays in the groups max of 4 disks and wait approximately 1 minute for the initialization of all added disks...
the pain is one part of the reality
IBaltay
Honored Contributor

Re: Adding more disks to existing disk groups

so there is no difference between the addition them from the bottom to the top but there is a difference to let them nicely vertical (across 8 physical enclosures) not to have them 2 in one enclosure...
the pain is one part of the reality
Ebk
Advisor

Re: Adding more disks to existing disk groups

I realize that your option C) sounds like the one I need to go for to leave the disks of disk groups 2 all together. at least for now...

Thanks
Ebk
Advisor

Re: Adding more disks to existing disk groups

Thread closed.
IBaltay
Honored Contributor

Re: Adding more disks to existing disk groups

nono, it is my mistake, i wanted to say no matter where you will plug the new disks that it is always good to have it in 8 - verticaly across 8 physical bays...
the pain is one part of the reality
IBaltay
Honored Contributor

Re: Adding more disks to existing disk groups

errata not bays but enclosures... :-)
the pain is one part of the reality