Yesterday I attended an IBM technical overview of their latest mid-range storage product the Storwize V7000 and I must admit I'm rather taken with it!

Imagine your favourite parts of the IBM Storage portfolio packaged into one:

Recently I have seen some strange behaviour with the later levels of firmware (around version 7.10 upwards) whereby a failed drive that has reconstructed to the hot spare does not automatically copyback when a new drive is inserted. The disk appears in storage manager as Optimal and Unassigned and logs indicate it has been picked up without error.

In later versions of IBM Storage Manager (versions 10.10 and up). There is a new function included "Replace Drives" that allows the user to select whether to replace a failed drive with any unassigned drive in the subsystem or the hot spare drive. It should be possible use this function to initiate the copyback. In some cases, I have seen that when the option "Replace Drives" is selected, the message is displayed "no drives available for replacement", despite the fact that unassigned drives are clearly available. In my investigations I have checked that the new drive was inserted correctly (leaving 30 seconds between the pull of the old and insertion of the new). I have seen that the new disk is of exactly the same type and brand and running the same level of firmware and that there do not appear to be any obvious problems within the event log,

The resolution so far has been simply to wait (even up to 2 days), and eventually, the "Replace Drives" option will recognise the available drive(s). So far, the only indication of what has occurred between these times has been that the regular media scan (scrub) has kicked off. Note that if a Storage Subsystem password is set, this is required to authorise the copyback.


The "Replace Drives" function does not appear to be clearly documented in the new Storage Manager client Redbooks so I will blog regards what I know of this function later.

Speak to one of our technical experts now to see how Centiq can help your business by requesting a "call back" using the button to the right, or calling us on 0115 951 9666

Be aware that unlike like IBM System Storage DS4000 series range, the cache batteries within the IBM System Storage DS3000 series Subsystems (including DS3200, DS3300 and DS3400) are not covered under IBM warranty. This means that when they fail a replacement part must be purchased even if the unit is under standard or uplifted warranty.

IBM state in Retain Tip H194543 that "the battery is designed to have a life expectancy of two (2) years and to maintain the data in cache for up to three (3) days in the event of a power outage".

The replacement part can be requested from your IBM Sales Representative or an IBM Business Partner such as Centiq. The part required is:
DS3000 System Memory Cache Battery, Option 39R6519

Retain Tip H194543 also recommends that users upgrade the subsystem controller firmware to 07.35.41.00 or later to benefit from the Smart Battery Learn Cycle technology which monitors battery life and will override the "Battery Nearing Expiration" warning if it determines that the battery is still in good order.

Note that in order to calculate battery life, the "Smart Battery Learn Cycle" performs a discharge and charge every 13 weeks during which time write cache will be suspended and this could impact on the performance of the system. This Smart battery feature can be disabled if preferred.

*A small set of batteries may not support this Smart battery technology - see the Retain Tip for more information*

For more information contact Emily on 0115 951 9666 or visit the Centiq website, Nottinghams Premier IT Specialists company.

 Capacity on Demand (CoD) is a feature of IBM's Power Systems designed to provide an easier way to upgrade your server resources when the need arises.

The IBM System Storage DS4000 cache battery provides valuable backup for the controller cache in the event of a subsystem power failure. The battery will allow the controller cache to be de-staged (i.e. written to disk) safely and ensure data remains consistent.
In older levels of controller firmware, these batteries were set to notify regarding an impending expiration at 36 months followed by cache disable action by the microcode at 39 months. When the cache disables, you could experience performance degradation since the controller's high speed cache is no longer in use.

IBM now state that in fact these DS4000 batteries can last well past 62 months and in controller firmware 6.60.02.00 and onwards a notification is now set to occur at 62 months followed by the cache disable action by the microcode a little after ten years.

I have found that when logging calls with IBM for the "Battery Nearing Expiration" notification, if the firmware is below 6.60.02.00 they simply tell me to reset the battery age to zero. Of course if the battery has actually failed then this would be replaced as usual under maintenance.

It's worth noting that there are no diagnostics to trigger the expiration notification and the date is purely hardset in microcode.

All this information was obtained from IBM retain tip H193840.
For more information contact Emily on 0115 951 9666 or visit the Centiq website, Nottinghams Premier IT Specialists company.

You see the error:

ERROR: Cluster verification detected that some of the disks on the cluster use both hdisks and device paths on different nodes. To ensure correct device processing, please
confgure all nodes to use either hdisk or vpath devices for the following PVIDs:
     PVID: 00a8558e51a39da30000000000000000
     node2: hdisk108
     node1: hdisk15

This error may be related the following APAR:
http://www-01.ibm.com/support/docview.wss?uid=isg1IZ42686

If you have recently replaced a hard drive on the server, you should ensure that all 'Defined' devices are removed and then re-run cluster verification.

It's important to keep you version of HACMP up to date with the latest fixes to avoid problems like this.

Speak to one of our technical experts now to see how Centiq can help your business by requesting a "call back" using the button to the right, or calling us on 0115 951 9666

IBM have released a new ESM and hard drive firmware package for the ESMs of the IBM DS4000/DS5000 Storage Subsystem range.
The new firmware bundle version 1.65 is an update to the previous version 1.64 and can be downloaded from the following link: 

IBM have released a new ESM and hard drive firmware package for the ESMs of the IBM DS Storage Subsystem range.

The new firmware bundle version 1.63 is an update to the previous version 1.62 and can be downloaded from the following link: