OctavioG1
2 Iron

Scheduling a refresh of an snapshot

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Hello Everyone:

The last week, we create an Consistency Group and a Snapshot set for him. The Snapshots volumes were presented to AIX Test  Server and customer could recognize the snapshot volumes in the OS and start up the Oracle DB.

Now, Customer is asking a refresh of the snapshot. In the last two days,  we did tests with the refresh option in the GUI for the Snapshot Set and everything worked so very well.

The only point, is that we don't see any option to schedule the refresh of the snapshot set .... I did a SR and the answer was "not possible schedule a refresh of snapshot", only possible by demand using the GUI.

We're requiring run the refresh every Sunday at 4:00 am. Somebody, can say me if there is any way to schedule the refresh by cron using CLI ? ... or any other method ??

Thank you in advance for your help.

1 Solution

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scotthoward
2 Iron

Re: Scheduling a refresh of an snapshot

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The reason we don't support a scheduled refresh from within XtremIO is that a refresh will normally require more than just action on the array - it'll need you to do some stuff on the host first.

Before you refresh a snapshot you will need to make sure that nothing on the host has it mounted in any way. This isn't a requirement on the array side (the refresh will work regardless), but if the host is still using the device when it's refreshed (eg, the filesystem is still mounted, or Oracle ASM still has the diskgroup mounted, etc) then the host will see this as data corruption - as the data on the LUN changed without it's knowledge.

Thus a typical refresh operation (on any array, not just XtremIO) will look something like :

* Stop any application using the LUNs being refreshed (eg, Oracle)

* Unmount filesystems/diskgroups/etc using those LUNs

* Refresh

* Re-mount the diskgroups/filesystems/etc

* Restart the application

If you want to schedule this there's really 2 options, either script it yourself (including all of the steps above in the script) with the refresh step being done using the XtremIO API, or use EMC AppSync which will handle most/all of it for you.

If you want to script it, https://blog.docbert.org/xtremio-snapshot-refresh/ would be a good place to start (especially the link at the very bottom to details on using the API).

If you want to look at AppSync talk to your EMC account team.  An AppSync Starter Bundle (up to 20 mounted copies - far more than enough for most people) is included free with XtremIO.

6 Replies
scotthoward
2 Iron

Re: Scheduling a refresh of an snapshot

Jump to solution

The reason we don't support a scheduled refresh from within XtremIO is that a refresh will normally require more than just action on the array - it'll need you to do some stuff on the host first.

Before you refresh a snapshot you will need to make sure that nothing on the host has it mounted in any way. This isn't a requirement on the array side (the refresh will work regardless), but if the host is still using the device when it's refreshed (eg, the filesystem is still mounted, or Oracle ASM still has the diskgroup mounted, etc) then the host will see this as data corruption - as the data on the LUN changed without it's knowledge.

Thus a typical refresh operation (on any array, not just XtremIO) will look something like :

* Stop any application using the LUNs being refreshed (eg, Oracle)

* Unmount filesystems/diskgroups/etc using those LUNs

* Refresh

* Re-mount the diskgroups/filesystems/etc

* Restart the application

If you want to schedule this there's really 2 options, either script it yourself (including all of the steps above in the script) with the refresh step being done using the XtremIO API, or use EMC AppSync which will handle most/all of it for you.

If you want to script it, https://blog.docbert.org/xtremio-snapshot-refresh/ would be a good place to start (especially the link at the very bottom to details on using the API).

If you want to look at AppSync talk to your EMC account team.  An AppSync Starter Bundle (up to 20 mounted copies - far more than enough for most people) is included free with XtremIO.

OctavioG1
2 Iron

Re: Scheduling a refresh of an snapshot

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Thank you Scott, so much .

Yes, we already, have the script with all the steps and command in order to get the database down and vg deactivated before to do the refresh of the snapshot. Actually, the script was being used previously with RecoverPoint Instructions.. So, I'm looking for the best "method" to include in the script the instructions for the refreshing of the XtremIO snapshot  set. Looks like CLI, would be the recommended. The script has been running from an AIX Server.

Question:   Could use XtremIO API in an AIX Server ... is there any procedure or document describing that process ?? ..

Thank you in advance

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Avi3
3 Zinc

Re: Scheduling a refresh of an snapshot

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If you are looking to script the whole process, the recommendation would be to use the RestAPI interface for doing snapshot and refresh operations. Have you looked at the RestAPI guide for XtremIO on the Support website?

OctavioG1
2 Iron

Re: Scheduling a refresh of an snapshot

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Hi Avi:

Yes ... now I have two sources: 

the First  mentioned by you: RestAPI guide  and  the provided by Scott: https://blog.docbert.org/xtremio-snapshot-refresh/

I should say, that I'm not expert using API.. but I have a good experience with shell scripting. So i'll do my best effort.

Thank you ...

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OctavioG1
2 Iron

Re: Scheduling a refresh of an snapshot

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Hello Everyone..

Scott and Avi:

Just want to let you know, that today we install the curl application in the AIX Server, where the snapshots volumes are being presented and I used the instructions provide by the API guide and the Scott blogs. Then I add the api instructions with curl to the script where all process is executed: shutdown of database, shutdown asm, etc.. we did three tests and everything is working very very fine... Really easy to use REST API with XtremIO ...

Thank  you so very much for your comments here .. they were very helpful and the best I have script working with XtremIO.

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Avi3
3 Zinc

Re: Scheduling a refresh of an snapshot

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Great – thanks for the update

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