Snapshot XP software Vs Netapp flexclone

[Ninad_1]

Does any one use the Storageworks Snapshot XP software ? What do you primarily use this software for ?
Is there any software from HP which is similar to Netapp flexclone software - which creates instant point-in-time copy of the production volumes and can be used for say backup/development environments. The flexclone volumes are created by copying the metadata from the production volumes and any changes to data are recorded in additional storage (so only the changed data occupies additional space).
As I understand from some material I read on the HP Snapshot software - it has somewhat similar concept - only I am not able to understand if the snapshot volumes so created - whether they can be used by the development environments ? Are these volumes writeable by the development environments ?
If Snapshot is not the software similar to flexclone then is there any other ?

Thanks,
Ninad

[Albert_31]

Hello Ninad,

From what I understand of your query, here are my answers.

a) Snapshot is read only.
b) HP Storageworks Snapshot XP also creates instant Point in time copy of the primary volume..similiar to what you have described for flexclone..
c) If you want to make the snapshot read-write then you have to go for a product which has the cloning facility. This depends on the storage type you are talking about. Let me know the storage so I can help you find the correct software product.

regards

albert

[Ninad_1]

a) Snapshot is read-only - So can I use snapshot volumes made available to the same (production) server or any other server (backup server) to take backup from the snapshot volumes ?
c) I wish to know all software similar to flexclone for any HP/HDS storage array (Please mention which array can be used)- mid-range to high end. I need to check if we can use software similar to flexclone to get full size development environments, which should have read-write access, without needing storage to accomodate a full copy of the production.

Also if anybody has experience of using such software, what are their experiences and words of caution.
Thanks and regards,
Ninad

[Chan 007]

Ninad,

I1st would like to clear you that I am not using this netapps software. I am having both XP & EMC software.

But here are the details that your are looking for.

XP:Snapshot, details can be found in, but I think it works only on XP1200, as per this.

http://h18000.www1.hp.com/products/storage/software/snapshotxp/index.html

http://h18000.www1.hp.com/products/storage/software/snapshotxp/qa.html#1

Netapps:
http://www.netapp.com/products/software/flex.html

What I understand is that only with clone it may not be possible, you need flexvol too.

But both does the same thing in creating a virtiul copy of the DB & keeps track of new changes. For e.g When you are taking backup & If your data is 1 TB, till backup is completed your original Data (1TB) is not used, whereas an new track table (DB) will be created with some 50/100GB (assuming) where all the changes will be copied, once your backup is completed, this tracktable will update the original copy.

Hope this helps.

Chan

[Ninad_1]

Chan,

Nice to see your reply.
Are you using Snapshot XP software ?
My question is - or rather let me clarify in the flexclone a bit - I have already read through some flexclone docs from Netapp and heres my understanding. There is a bit miunderstanding - when you say that after backup the changed data is updated - its not so.
Say you have a 1 TB database - using flexvols. Now you want a development database to be an updated copy of the production database. So during say backup time or whatever when dataabse is down I create flexclones - these now can be assigned to development server and it will think that it has its own copy of database.
Now suppose the production database is back and changes are happening - before the actual block is changed the original data is copied to another block so that flexclone can reference the unmodified data and then the production changed data is updated to the original block. Now suppose during development phase there are some changes to data these are recorded to new blocks again. Thus the production as well as development can write without actually consuming 2 * database size of storage.

Is there something similar to this from HP for XP arrays or HDS for HDS arrays.
Also has anyone used Netapp clones with HP-UX (I am aware of the documents, I would like to hear any real life experience)

Thanks and regards,
Ninad

[Zinky]

Ninad, we do not use any of the array based SnapShot/Clone software as we mirror/snap accross different arrays. Hence we use host-based solutoins like VxVM FlashSnap, etc.

Hope this Helps.

[Peter Mattei]

A snapshot XP volume is from the server perspective identical to a standart Business Copy XP volume.
Thus a snapshot volume is read/write
The difference is that while BC is a 100% clone snapshots only keep delta data in a pool area. If you write to the primary volume the track to be changed will first be copied to the pool area to keep the snapshot consistent. This is called copy on write.

If you want to read more about see here
http://h18006.www1.hp.com/products/storage/software/snapshotxp/index.html

A maula can be found here:
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00633928/c00633928.pdf


Cheers
Peter

[Ninad_1]

Hi Peter,

Can the PVOL and SVOL copies of the snapshot be read/write ? As per the manual of Snapshot XP page 24 read/write to SVOl is possible in PSUS/PSUF states.
So is following possible ?
A]
1)Can I present the PVOL and SVOL volumes to the same host and import the VGs ? Wont there be a clash in VGID for the 2 copies ?
2) Can I then have writes to both PVOL as well as SVOL volumes ?

B]
1) Can I present the PVOL and SVOL volumes to different hosts ?
2) Suppose the SVOLs are presented to a development server, can I then have writes to PVOL by host1 and writes to SVOL by host2 ?

Will the pool allocate space to writes for both PVOL and SVOL ?

Thanks and regards,
Ninad

[Peter Mattei · Accepted solution]

Ninad

Yes, a snapshot volume can be used similar to a BC volume, thus in if in PSUS mode (suspended) you can read an write to it!

A1) no, you cannot present the S-Vol to the same host unless you change the vg credentials.
A2) see above

B1) sure you can, like a BC volume
B2) Yes, that is OK

No the pool is only used for deltas of the S-vols! Remember the P-Vol will be written to directly. What changes is, that before writing to the P-vol the XP copies the data from the P-Vol to the pool area (copy on write)

Cheers
Peter

[Ninad_1]

Thanks all.
Thanks Peter again for your help.

Regards,
Ninad

[Zinky]

Ninad,

Did you end up using Snapshot/XP? We're looking at it to have the utmost protection and "roll-backability" of our multi-TB sized Databases.And this alongside with Full clones (BusinessCopy/XP) - which I heard is now possible...

Peter M. any word of wisdom as to the viability of Snapshot/XP? Also does it now support External Storage?

[Peter Mattei]

Hi Nelson

Yes, snapshot sources and pools can now reside on external storage since FW 50-07-30-00.

Snapshot XP is a mature solution. It needs careful planning to keep up high performance due to copy on write effects and possible pool contention.

Cheers
XP-Pete

[Zinky]

Peter..

Would this "proper" configuration be one of the service that we can "buy" for an engagement with a MASE?

Any suggested readings/docus on External Storage/XP, BusinessCopy and Snapshot/XP?

Our DBA Team is skeptical about in-array based BCV or SnapSHot solutions and are actually for having Standby Databases instead that will be "6 hours behind in archive logs" -- so the issues we're trying to address - i.e. quick rollback and recoverability can be "addressed" ,etc.

We currently use VxVM Host Based Flashsnap (former Fast Mirror Resynch). It's served us well over the years but is no longer viable as our DB's have now reached multi-TB in size and our "resynch" windows are getting tighter and is alredy impacting performance a lot. I am for a BusinessCopy/Extenral Storage/XP solution considering we've an XP12K and an EVA8K ecosystem -- which is perfect for this kind of solution.

[Peter Mattei]

Sure, XP professionals can help you deploying an optimal XP layout!

I recommend having a look at the XP whitepapers on the HP storage whitepaper site on:
http://h18006.www1.hp.com/storage/arraywhitepapers.html

Especially have a look at the XP12000 performance whitepaper:
http://h71028.www7.hp.com/ERC/downloads/4AA0-7923ENW.pdf
and the XP External Storage WPs:
http://h71028.www7.hp.com/ERC/downloads/4AA0-6162ENW.pdf and
http://h71028.www7.hp.com/ERC/downloads/4AA0-7935ENW.pdf

Cheers
XP-Pete