topic Re: EVA controller resync in HPE EVA Storage

EVA controller resync

Gordon Bloxham — Thu, 16 Jul 2009 10:54:02 GMT

Does anyone know how long it takes an EVA controller to resync. I am trying to find out how long an 8100 takes and how long an 8400 takes

Re: EVA controller resync

Niels Vejrup Pedersen — Thu, 16 Jul 2009 11:59:06 GMT

Usually a controller resync takes less than 15 seconds. (when doing upgrades hp calculated with 30 seconds for the resync process after a controller reboot)

I can't find any written info on this, it's just what i've been told from hp.

Regards

Re: EVA controller resync

Gordon Bloxham — Thu, 16 Jul 2009 12:32:00 GMT

The reason I ask this is that we have set scsi timeouts to 60 seconds and resyncs sometimes have been taking longer. I am interested to see what everyone else has been told.

Re: EVA controller resync

Niels Vejrup Pedersen — Thu, 16 Jul 2009 12:37:59 GMT

60 seconds are also usually sufficient depending on the TB in your EVA.

There will be improvements since newer EVA's with more disks, and larger disks will require more time reading the metadata - but in future XCS version on the x400 series there will be improvements not needing to read the metadata from disk, but having it in policy memory through the reboot of the controllers.

Since 2006 HP has done a really good work in their online upgrades, so i would not be too worried about OS timeouts - IF set to 60 seconds.

But as always please do a performance analysis of the EVA before upgrading - there is a semi automatic tool for this now - the Upgrade Advisor.

Regards

Re: EVA controller resync

IBaltay — Thu, 16 Jul 2009 18:22:58 GMT

Hi,
this is an older document
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c00795548/c00795548.pdf

newer document for EVA 44xx/64xx/84xx (page 31)
http://h20000.www2.hp.com/bc/docs/support/SupportManual/c01680630/c01680630.pdf

Selecting an appropriate time to perform an online upgrade
To ensure the success of an online upgrade, selecting the appropriate time is essential. Because the
online firmware upgrade is performed while host I/Os are being serviced, the I/O load can impact
the upgrade process. Selecting a period of low I/O activity will ensure the upgrade completes as
quickly as possible, and will avoid disruptions to host and applications due to timeouts.
While there are advantages to performing an online upgrade, there are circumstances when it is not
advisable. Therefore, give careful consideration to the circumstances of your configuration and your
application deployment before making an attempt to do an online upgrade.

There is a section for
Managing host I/O timeouts for an online upgrade here

Re: EVA controller resync

Chris Callihan_1 — Fri, 17 Jul 2009 12:37:17 GMT

HP has a tool called the EVA Upgrade Schedule Advisor

HP StorageWorks EVA Upgrade Scheduling Advisor (EVA Upgrade Scheduling Advisor) software enables you to monitor and analyze the I/O load on the EVA storage system. It suggests the timelines to perform an EVA firmware upgrade through an easy-to-use GUI. EVA Upgrade Scheduling Advisor also allows you to set and restore the recommended SCSI driver timeout values (as described in the EVA online firmware upgrade best practices guide) for Windows hosts.

- check with you local team to see if they can assist you with this tool

Re: EVA controller resync

Del_3 — Fri, 17 Jul 2009 17:43:32 GMT

Maybe there is something I dont understand here but seems the OS is only secondary to the application. So if your app - SQL, Oracle or the worst - Exchange, times out before 60 seconds the online update will cause application problems.

Please set me straight.

Re: EVA controller resync

Niels Vejrup Pedersen — Sun, 19 Jul 2009 09:18:28 GMT

Hello,

You right - Application timeouts also need to be taken care of.

Regards,

Re: EVA controller resync

Gordon Bloxham — Mon, 20 Jul 2009 11:34:26 GMT

The think that is issing is that I no resyncs are taking longer than 60 seconds. I jus wantedto find out everyone elses experience of this.

Re: EVA controller resync

Vinod Kumar Yadav — Mon, 20 Jul 2009 17:57:08 GMT

Hi,

The HP EVA Controller Resync will take max time to sync between 60 second usually.

Other wise just check in the HP Command EVA SMA Server status of the both controller.

If it is showing any yellow alert sign at controller A & B.

Then Check the log of command view EVA
for more information.

Thanks
Vinod Kumar Yadav

Re: EVA controller resync

Gordon Bloxham — Tue, 18 Aug 2009 09:55:38 GMT

All,
it may interest you to know that 60 seconds is not the maximum resync time. the time depends on the size of your EVA. HP have a formula to work this out so I would suggest you all chase your account team to get this info.

Re: EVA controller resync

Niels Vejrup Pedersen — Sun, 23 Aug 2009 20:37:18 GMT

The formula is easy.

Reserved resync time for controllers 30sec
Add 0.7sec per 1TB og RAW storage on the array.

Please note that this does not apply to x4xx EVA's.

Regards

Re: EVA controller resync

Gordon Bloxham — Wed, 02 Sep 2009 06:24:08 GMT

So does anyone knoe the formula fr he xx400 series?

Re: EVA controller resync

Niels Vejrup Pedersen — Mon, 07 Sep 2009 06:35:17 GMT

Hello,

The x4xx series has the same reserved time for controller reboot (30sec)

But the main difference is that, the metadata is read from policy memory instead from disk, so it is very fast.

From what i've heard there is no formula on these arrays, since memory speed are very fast.

Regards