Tag Archives: cx4-960

EMC – Maximum Pool LUN Size

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Mat has been trying to create a 42TB LUN to use temporarily for Centera backups. I don’t want to go into why we’re doing Centera backups, but let’s just say we need the space. He created a Storage Pool on one of the CX4-960s, using 28 2TB spindles and 6+1 private RAID Groups. However, when he tried to bind the LUN, he got the following error.

err1

Weird. So what if we set the size to 44000GB?

err2

No, that doesn’t work either. Turns out, I should really read some of the stuff that I post here, like my article entitled “EMC CLARiiON VNX7500 Configuration guidelines – Part 1“, where I mention that the maximum size of a Pool LUN is 16TB. I was wrong in any case, as it looks more like it’s 14TB. Seems like we’ll be using RAID Groups and MetaLUNs to get over the line on this one.

EMC – CX4 Configuration – a few things I’d forgotten

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I’ve been commissioning some new CX4-960s recently (it’s a long story), and came across a few things that I’d forgotten about for some reason. If you’re running older disks, and they get replaced by EMC, there’s a good chance they’ll be a higher capacity. In our case I was creating a storage pool with 45 300GB FC disks and kept getting the following error.

This error was driving me nuts for a while, until I realised that one of the 300GB disks had, at some point, been replaced with a 450GB drive. Hence the error.

The other thing I came across was the restriction that Private LUNs (Write Intent Log, Reserved LUN Pool, MetaLUN Components) have to reside on traditional RAID Groups and can’t live in storage pools. Not a big issue, but I hadn’t really planned to use RAID Groups on these arrays. If you search for emc254739 you’ll find a handy KB article on WIL performance considerations, including this nugget “Virtual Provisioning LUNs are not supported for the WIL; RAID group-based LUNs or metaLUNs should be used”. Which clarifies why I was unable to allocate the 2 WIL LUNs I’d configured in the pool.

*Edit* I re-read the KB article and realised it doesn’t address the problem I saw. I had created thick LUNs on a storage pool, but these weren’t able to be allocated as WIL LUNs. Even though the article states “[The WIL LUNs] can either be RAID-group based LUNs, metaLUNs or Thick Pool LUNs”. So I don’t really know. Maybe it’s a VNX vs CX4 thing. Maybe not.

EMC – CX4 FAST Cache cosmetic issues and using /debug

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I noticed that one of our CX4s was exhibiting some odd behaviour the other day. When looking at the System Information window, I noticed that FAST Cache seemed broken. Here’s a picture of it.

Going to the FAST Cache tab on System Properties yielded the same result, as did the output of naviseccli (using naviseccli -h IPaddress cache -fast -info). Interestingly, though, it was still showing up with dirty pages.

We tried recreating it, but the 8 * 100GB EFDs we were using for FAST Cache weren’t available. So we logged a call, and after a bit of back and forth with support, worked out how to fix it. A few things to note first though. If support tell you that FAST Cache can’t be used because you’re using EFDs, not SSDs, ask to have the call escalated. Secondly, the solution I’m showing here fixes the specific problem we had. If you frig around with the tool you may end up causing yourself more pain than it’s worth.

So, to fix the problem we had, we needed to log in to the /debug page on the CX4. To do this, go to http://<yourSPaddress>/debug.

You’ll need your Navisphere or LDAP credentials to gain access. Once you’ve logged in, the page should look something like the following (paying particular attention to the warning).

 Now scroll down until you get to “Force A Full Poll”. Click on that and wait a little while.

Once this is done, you can log back into Unisphere and FAST Cache should look normal again.

 Hooray!

EMC – Check on a RAID Group’s defragmentation progress with naviseccli

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For those of you still using RAID Groups on the CX4, you’ll know that you sometimes need to defragment them to get a contiguous amount of free space, particularly if you’ve unbound LUNs in the group that sit between other, remaining LUNs. If you kick off a whole bunch of defrags and then want a quick way to check the progress, why not use naviseccli? The getrg option is the one you want to use in this example.

naviseccli -h 256.256.256.256 getrg -prcntdf

The output will look something like this:

RaidGroup ID: 0
Percent defragmented: 100
RaidGroup ID: 1
Percent defragmented: 100
RaidGroup ID: 2
Percent defragmented: 100
RaidGroup ID: 3
Percent defragmented: 1
RaidGroup ID: 4
Percent defragmented: 1
RaidGroup ID: 5
Percent defragmented: 100
RaidGroup ID: 6
Percent defragmented: 2
RaidGroup ID: 7
Percent defragmented: 1
RaidGroup ID: 8
Percent defragmented: 100

 

EMC – Flash LEDs with naviseccli

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Sometimes, like when you have 64 DAEs across 5 racks, it’s useful to be able to tell which DAE you need to be working on. You can flash the LEDs of a DAE via Unisphere, but where’s the fun in that? Using naviseccli you can also do it as follows:

usage: flashleds -e <enclosure number> [-b <bus number>] <on|off>
C:\Users\dan>naviseccli -h 10.196.8.10 flashleds -b 4 -e 1 on Enclosure 1 ON
C:\Users\dan>naviseccli -h 10.196.8.10 flashleds -b 4 -e 1 off Enclosure 1 OFF

It’s a simple thing, but handy to know when you’re scratching around in the data centre trying to remember which disks you were meant to be pulling out of which production array.

EMC – Why FAST VP Best Practice is Best Practice

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Those of you fortunate enough to have worked with me in a professional capacity will know that I’m highly opinionated. I generally try not to be opinionated on this blog, preferring instead to provide guidance on tangible technical things. On this occasion, however, I’d like to offer my opinion. I overheard someone in the office recently saying that best practices are just best practices, you don’t have to follow them. Generally speaking, they’re right. You don’t have to do what the vendor tells you, particularly if it doesn’t suit your environment, circumstances, whatever. What annoys me, though, is the idea that’s been adopted by a few in my industry that they can just ignore documents that cover best practices because there’s no way the vendor would know what’s appropriate for their environment. At this point I call BS. These types of documents are put out there because the vendor wants you to use their product in the way it was meant to be used. And – get this – they want you to get value from using their product. The idea being that you’ll be happy with the product, and buy from the vendor again.

BP Guides aren’t just for overpaid consultants to wave at know-nothing customers. They’re actually really useful guidelines around which you can base your designs. Crazy notion, right?

So, to my point. EMC recommend, when you’re using FAST VP on the CLARiiON / VNX, to leave 10% free space in your tiers. The reason they recommend this is that they want FAST VP to have sufficient space to move slices between tiers. Otherwise you’ll get errors like this “712d841a Could not complete operation Relocate 0xB00031ED4 allocate slice failed because 0xe12d8709”. And you’ll get lots of them. Which means that FAST is unable to move slices around the pool. In which case why did you by FAST in the first place? For more information on these errors, check out emc274840 and emc286486 on Powerlink.

If you want an easy way to query a pool’s capacity, use the following naviseccli command:

naviseccli -h ipaddress storagepool -list -tiers
Pool Name: SP_DATA_1
Pool ID: 3

Tier Name: FC
Raid Type: r_5
User Capacity (GBs): 33812.06
Consumed Capacity (GBs): 15861.97
Available Capacity (GBs): 17950.10
Percent Subscribed: 46.91%
Data Targeted for Higher Tier (GBs): 0.00
Data Targeted for Lower Tier (GBs): 0.00
Disks (Type):

Bus 6 Enclosure 7 Disk 14 (Fibre Channel)
Bus 6 Enclosure 7 Disk 12 (Fibre Channel)
Bus 6 Enclosure 7 Disk 10 (Fibre Channel)
Bus 3 Enclosure 5 Disk 3 (Fibre Channel)
Bus 3 Enclosure 5 Disk 1 (Fibre Channel)
Bus 4 Enclosure 5 Disk 2 (Fibre Channel)
Bus 4 Enclosure 5 Disk 0 (Fibre Channel)
[snip]
Bus 2 Enclosure 6 Disk 14 (Fibre Channel)
Bus 2 Enclosure 6 Disk 12 (Fibre Channel)
Bus 2 Enclosure 6 Disk 10 (Fibre Channel)
Bus 0 Enclosure 2 Disk 0 (Fibre Channel)
Bus 5 Enclosure 6 Disk 8 (Fibre Channel)
Bus 3 Enclosure 2 Disk 4 (Fibre Channel)
Bus 7 Enclosure 5 Disk 6 (Fibre Channel)

Pool Name: SP_TEST_10
Pool ID: 2
Tier Name: FC
Raid Type: r_10
User Capacity (GBs): 1600.10
Consumed Capacity (GBs): 312.02
Available Capacity (GBs): 1288.08
Percent Subscribed: 19.50%
Data Targeted for Higher Tier (GBs): 0.00
Data Targeted for Lower Tier (GBs): 0.00
Disks (Type):
Bus 1 Enclosure 7 Disk 3 (Fibre Channel)
Bus 1 Enclosure 7 Disk 5 (Fibre Channel)
Bus 1 Enclosure 7 Disk 7 (Fibre Channel)
Bus 1 Enclosure 7 Disk 2 (Fibre Channel)
Bus 1 Enclosure 7 Disk 4 (Fibre Channel)
Bus 1 Enclosure 7 Disk 6 (Fibre Channel)
Bus 1 Enclosure 7 Disk 9 (Fibre Channel)
Bus 1 Enclosure 7 Disk 8 (Fibre Channel)

And if you want to get the status of FAST VP operations on your pools, use the following command:

naviseccli -h ipaddress autotiering -info -opstatus
Storage Pool Name: SP_DATA_1
Storage Pool ID: 3
Relocation Start Time: N/A
Relocation Stop Time: N/A
Relocation Status: Inactive
Relocation Type: N/A
Relocation Rate: N/A
Data to Move Up (GBs): 0.00
Data to Move Down (GBs): 0.00
Data Movement Completed (GBs): N/A
Estimated Time to Complete: N/A
Schedule Duration Remaining: N/A

Storage Pool Name: SP_TEST_10
Storage Pool ID: 2
Relocation Start Time: N/A
Relocation Stop Time: N/A
Relocation Status: Inactive
Relocation Type: N/A
Relocation Rate: N/A
Data to Move Up (GBs): 0.00
Data to Move Down (GBs): 0.00
Data Movement Completed (GBs): N/A
Estimated Time to Complete: N/A
Schedule Duration Remaining: N/A

And next time you’re looking at a pool with tiers that are full, think about what you can do to alleviate the issue, and think about why you’ve automatically ignored the best practices guide.

EMC – DIY Heatmaps – Updated Version

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Mat has updated the DIY Heatmaps for EMC CLARiiON and VNX arrays to version 3.019. You can get it from the Utilities page here. Any and all feedback welcome.

Latest fixes:

· Search Path environment variable for naviseccli

· Search common install locations for naviseccli

· Improve cross browser support – tested on IE, Chrome and FireFox

· Improve debug details – add module version reporting

· Fix divide by zero bug in rendering routine

Updated Articles page

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A few months ago someone asked me if I had documentation on how to do FLARE upgrades on a CLARiiON. I’d taken a video last year, but realised that it used the old Navisphere Service Taskbar and covered the upgrade of a CX700 to FLARE 26. So, basically, my doco was a little out of date.

I recently had the opportunity to upgrade some of our CX4-120s to the latest release of FLARE 30 (.524), so thought it might be an opportune moment to document the process in a visual sense. Once I’d completed the articles, I realised this may have been done better with a series of videos. Maybe next time. In any case, here’s a four-part series (part 1, part 2, part 3, and part 4) on how to upgrade FLARE on a CX4 using Unisphere Service Manager. It’s a classic death-by-screenshot scenario, and I apologise in advance for the size of the files. While we’re talking about documentation, have a look through the rest of the articles page, there might be something useful there. And if you want something covered specifically, I do take requests.

EMC – DIY Heatmaps – Updated Version

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Mat has updated the DIY Heatmaps for EMC CLARiiON and VNX arrays to version 3.018. You can get it from the Utilities page here. Any and all feedback welcome.

Latest fixes:

## 0.3.016 Add options to add array name and SP name to output file

## Fix –display_drive_type so that it displays empty drive slots as white, Removed / Failed drives as gray and unknown as green

## Add attributes to display total array and bus IOPS and Bandwidth

## Add –display_actual option to view actual IO stats

## Add read and write attributes for SP IOPS and bandwidth metrics

## Add –time_zone option

## Add the time zone to the heatmap output

## Add LUN bandwidth total, read & write and LUN IOPS total, read & write attributes

## Fix display problem when all of trays have their last disks configured as hotspares or not in use

## Add 2TB drive size

## 0.3.017 Change display options to allow controll of how many Disk, LUN and SP heatmaps per column

## Add –disk_maps, –lun_maps and –sp_maps

## 0.3.018 Add –debug option to print detailed debug information

EMC – new FLARE 30 available

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Just a quick note that FLARE 30 for the CX4 has received an update to version .524. I haven’t gotten hold of the release notes yet, so I can’t say what’s been fixed, etc. As always, go to Powerlink for more info, and talk to your local EMC people about whether it’s appropriate to upgrade your CX4(s).