Hello, welcome to the VNX disk replacement video. In this video, we will briefly discuss about features such as permanent sparing, drive mobility and hot spare policy provided by Multicore RAID (MCR), which was introduced with the MCx for the new VNX systems, followed by a demo on how to replace a faulted disk on the VNX systems.
MCR introduces the permanent sparing feature, which allows the permanent replacement of the failed drive with spares. When a drive fails, MCR spares into a suitable unused drive, and that new drive becomes a part of the RAID group or storage pool. When a failed drive is replaced, it simply becomes unused. Upon any drive failure, excluding the wall drive, MCR will wait for five minutes.
After the five minutes has passed, array looks for a suitable replacement on the array. When and if a match is found, the new drive is added to the RAID group and the rebuild process happens. MCR also introduces the drive mobility feature. Drive mobility, also known as “portable drives,” allows users to move VNX disks within the array. Drive mobility is very closely related to the permanent sparing feature.
MCR also introduces a new concept of hot spare policy to the VNX array, where a hot spare policy monitors the number of unused drives which can be potential spares of a certain type in the system and posts a warning when that number is low. There are three hot spare policies recommended where one hot spare is present for every 30 drives. “Custom” allows an administrator to specify the ratio.
And finally, the “No Hot Spare” policy. This turns off the policy monitoring. Note: the “No Hot Spare” policy does not stop sparing. A failed drive will always be spared given that a suitable unused drive can be found on the system. Now let’s take a look at the procedure to replace a faulted disk on the VNX, using USM. Unisphere Service Manager is a collection of tools which is used to install, upgrade and maintain VNX storage systems.
As part of the procedure, we will locate the faulted disk, replace the disk and verify the replaced disk on the VNX system. In this demo, we will be replacing a 2.5-inch disk. From the VNX Unisphere dashboard, you can see that under System Alerts, a faulted disk is reported. You can also notice that the corresponding DPE is reported as faulted. When a disk failure occurs on your system, you will see the alerts on your Unisphere dashboard.
Select the alert, right-click and select “Details.” Here you can see that disk 8 on bus 0, enclosure 0 is faulted. Click on “OK,” close the alerts window, and we will navigate to the backend storage view in Unisphere. Click on the System tab, select “Storage Hardware.” Here you can notice that the bus 0, enclosure 0 is faulted, and when you select the enclosure, you can see the pictorial representation of the enclosure.
Now let’s click on “Disks.” Here we can now scroll down to find the faulted disk. Now let’s select the faulted disk. The physical location of the faulted disk can also be seen on the diagram in the right. As you can see here, the picture taken from the array matches to what we see on the Unisphere. If we zoom in, you can notice that the fault disk is amber in color. Now you can right-click on the disk and select “Replace Disk.”
Once we click “Replace Disk” on Unisphere, this will automatically launch USM. USM, or Unisphere Service Manager, needs to be installed, and it can be downloaded from EMC online support. As you can see, we don’t have to manually log in to USM. The credentials are automatically passed to USM when we launch it from Unisphere. Now you can click on “Replace Faulted Disk.” The Disk Replacement Wizard appears.
This wizard determines if a disk needs to be replaced and provides the instructions on how to replace the disk. Click “Next” to continue. The VNX system will be analyzed. Once the analysis is complete, click “Next.” In the Disk Analysis Summary, you can notice that the storage system is a candidate for disk drive replacement, and it also represents the faulted disk which needs to be replaced.
You can click on “Save As...” and save this analysis and include this in the service request opened to replace the faulted disk. To order a replacement disk, you can click on the Support tab on on Unisphere, or USM, and launch the link to support.emc.com.
Click on “SUPPORT.” Here, click on “Service Center.” Now you can click on “Order a part replacement” to request a replacement for the faulted disk to be replaced on your system. Here we can create a service request to request for the replacement disk. For the purpose of this demo, we have the replacement disk ready. Click “Next” to continue. Here you can notice that the faulted disk is red in color. You also have the option to click on “Turn on enclosure LEDs,” which will flash amber lights on the enclosure and all the disks in the enclosure.
This will enable to easily find the enclosure on your array in your data center. Next, you can click on “Replacement Instructions,” which will provide the instructions on how to replace the faulted disk. Please review the instructions carefully before replacing the disk on your VNX system. The faulted disk needs to be carefully removed from the enclosure by pushing down the release tab.
Once the disk has been removed, insert the new disk into the slot until it’s properly seated, and push in the release tab. Once the disk has been replaced, you can put back the bezel on the DAE. For the purpose of this demo, we have already replaced the drive following the instructions we have seen before. Once the drive has been successfully replaced, you can now see that the status of the drive has turned to green. Click “Next” to continue.
Here you can notice the summary of the drive replacement procedure. You can now return the faulted drives back to your service provider. You can now click “Next” to register the service activity with your service provider. We will now log back in to Unisphere to verify the status of the replaced drive.
Now that the disk has been replaced successfully, from VNX Unisphere, you will notice that the drive is presently unbound and can be used for creating storage pools and RAID groups. For additional resources, you can review the USM release notes and “Replacing a Disk Module” section of Unisphere online help.
Thanks a lot for watching the video.
