Performance expectation of Business Copy

[Berd]

I have setup Business Copy for a 2.5TB database spread over 128 LUNS. I am yet to perform the initial paircreate as I am awaiting DB's to complete some work on the instance before doing so.

Is there any way I can predict how long the initial paircreate will take ?

Regards,
Berd

[whiz_kid]

i donno if any calculation sheet is available or not but it takes a bit longer and i guess it would be better to schedule it on a night or weekends.

[m saravanan]

Berd,

It all depends...

* Host IO on the array
* P-VOL & S-VOl location (different raid groups, diff ACP pairs)
* Copy pace setting (slow, medium & fast)
* Raid level (1/5)
* cache utilization
* Spindle speed


- saravanan

[Amar_Joshi · Accepted solution]

Berd,

If all the LUNs are of same size, you may try starting PAIRCREATE on 16 LUNs at a time and note the time, multiply by 7 to estimate the time for rest of the volume.

Note: paircreate can be done in "installments" but pairsplit must be done together.

On XP12000 with moderate load (30-50%), from RAID1 (16 10k RPM spindles) to RAID5 (16 10k RPM spindles) I have experienced 1TB in half an hour. So you if your XP is also moderately loaded, you can play safe to say 2 hours. But again it all vary as mentioned in previous posts.

[Alzhy]

And I trust, subsequent "resynchs" will be faster and dependent largely on how much changes there've been between sets?

We're just studying moving to BusinessCopy/XP (aka Hitachi ShadowCopy?).

Is it also possible to have more than one splittable set? What's the maximum?

Currently, all of our disk join and split operations are all HostBased (VxVM) --- it still works and we've no option as we deal with heterogenous arrays. But it is highly breakable and I think we've reached already a limit. And the fact that we will soon be virtualizing the other arrays via the XP12K - we'll now be able to use BusinessCopy/XP...


Thanks!

[Berd]

Nelson,

Thats correct, subsequent re-sync's will be quicker as only the amended blocks will be replicated.

I believe you can have upto 3 business copies of a single source.

Amardeep - I have 2 BC's of the same PVOL, would it be advisable to run the paircreate's simultaneously ?

Cheers,
Berd

[Alzhy]

Amardeep, Berd, et al,

Hmmm... then we'll have an issue then going with BusinessCopy. Our requirement is that for every multi-TB DB Instance - there could be anywhere from 4 to 8 "Clone Sets". With VxVM Flashsnap - we can have up to 32 sets that can be synched and resynched.

Any suggestions? Can BusinessCopy/XP perform nested clones? I.e. Clone from Clones?


Thanks and sorry for hijacking this thread.

[Berd]

Nelson,

I believe there is something similar. You may want to read up on cascaded copies in the attached doc.

Sorry doc was to big, you can pick it up at

http://h18006.www1.hp.com/products/storageworks/xp12000/relatedinfo.html

Look for Storage Software docs

Berd

[Amar_Joshi]

Hi Berd,

To answer your question about running 2 SVOLs for a single PVOL is a mathematics of ArrayGroups. In a well organised XP where PVOL and both SVOLs are configured on individual ArrayGroup and probably on separate ACP pairs, it's very much possible to run both the paircreate/pairresync together. Again make sure the applications are not heavy IO intensive to be affected by pair operations.

For the question about how many pairs can be created, it's in attached picture. A Volume can have upto 3 Business Copies, and each of these 3 copies can have 2 Business Copies from them.

My 2 cents worth.

[Amar_Joshi]

Sorry, forgot to attach the picture.