Category Archives: Configuration

How to upgrade a Cisco MDS SAN switch

Cisco MDS

After a few years of not having had to perform switch upgrades, I had to perform a few firmware upgrades on MDS switches. I decided to write down the steps I had to take:

  • First make sure you have a reachable ftp server somewhere and write down its ip address
  • Log on to the Cisco MDS SAN switch you need to upgrade
  • Make sure the bootflash: has enough available space to hold the 2 new files

# dir bootflash:

4096 Feb 23 14:58:04 2020 lost+found/
26049024 Feb 10 12:57:55 2020 m9100-s5ek9-kickstart-mz.8.3.2.bin
121121564 Feb 10 12:56:47 2020 m9100-s5ek9-mz.8.3.2.bin

Usage for bootflash://sup-local
463962112 bytes used
2894815232 bytes free
3358777344 bytes total

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How to match an Windows (HyperV) disk to a SAN attached disk using the wwn

Hard Drive

Where do I find the wwn of a disk in Windows / HyperV? That’s the question.

There are a number of identifiers to find out which LUN is which disk, but the only undeniably unique number to find out which disk is which LUN is by using the globally unique wwn number of a LUN. The question is: “where can I find the wwn of a disk in HyperV?”

The LUN number, as assigned by the storage array can be found by using diskpart:

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How to list the naa-numbers of LUNs and VMware VMFSs on a Dell EMC Unity system

EMC Unity

In the Unity the naa numbers (wwn) are listed in the “block” section, but not in the VMware section. If you view the LUNs from the host perspective, the naa numbers are visible, but in the list of LUNs  would have been easier. You can list all details from LUNs and datastores on the CLI by using the uemcli commands:

uemcli -d -u Local\admin -p [password] /stor/prov/luns/lun show -detail > unity.txt
uemcli -d -u Local\admin -p [password] /stor/prov/vmware/vmfs show -detail >> unity.txt

Now simply open the unity.txt file and voila: there they are!

How to enable a replica-LUN on Unity

EMC Unity

LUN-replication on Unity works slightly different than it previously did on VNX or even Clariion. In these older generations, when you deleted the mirrorview Mirror Group, both the primary and secondary LUNs became usable as separate entities.

In Unity the secondary LUN is a different beast. First of all: in Unity you can only set up replication from the primary Unity/LUN. The process on the source-Unity will create a LUN-replica and a replication session on both Unitys.

But what happens when you need hosts to access the secondary LUN? A failover works as designed and the previous secondary LUN becomes writable, but when you break the replication session, the replica-LUN has a flag that needs to be reset, but you’ll need the CLI to do that. This is how I did it:

  • In Unisphere I listed all LUNs and I made sure to include the “CLI ID” column
  • I noticed the ID of the LUN I need to grant access to is “res_56”
  • I started PUTTY and made sure logging to a file was configured so I could easily browse / search the possibly large amount of data some commands can produce, especially “-detail” commands tend to be very explicit
  • Log in as the “service” user to the Unity command line

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How to expand a LUN on VNX using the CLI

Once in a while you come across a storage system that cannot be managed through the GUI or you just want to script or use the CLI to perform management tasks on a VNX. Recently I came across an old VNX2 which GUI wasn’t responding the way I’d like, so I decided to use the CLI instead.

In this particular case I needed to expand a LUN.

First I listed the current size:

naviseccli -h [SPA/B ip#] -user [user] -password [password] -scope [scope] getlun [LUN#]

Then I expanded the LUN to the new size:

naviseccli -h [SPA/B ip#] -user [user] -password [password] -scope [scope] lun -expand -l [LUN#] -capacity [new capacity] -sq [mb/gb/tb/bc]

Pay attention to the number and the prefix! It could be a lot of work if you needed to resize a LUN from 50GB to 60GB and instead GB, you used TB…..

And finally I checked if the new size was actually available:

naviseccli -h [SPA/B ip#] -user [user] -password [password] -scope [scope] getlun [LUN#]

Sometimes CLI is so much easier than the GUI!

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