Category Archives: hardware - Page 6

Cisco zoning: some commonly used – show – commands

Posted by on April 7, 2015 No comments
Cisco MDS

When you need to look up the current zoning config of a Cisco SAN-switch / VSAN, there’s a number of commands that will help you. Because a “show run” doesn’t always do the trick well, especially if you have a large config. And using the “sh run | i “some text you’re looking for” doesn’t always help as well if you don’t know the exact phrase you’re looking for.

I hope this table helps:

show Command
 Description
show zone Displays zone information for all VSANs.
show zone vsan 100 Displays zone information for VSAN 100.
show zoneset vsan 100 Displays information for the zone set in VSAN 100.
show zoneset vsan 2-5 Displays configured zone set information for a range of VSANs (2, 3, 4 and 5 in this case).
show zone name AZone Displays members of zone “AZONE”.
show fcalias vsan 100 Displays fcalias configuration in VSAN 100.
show zone member pwwn 20:00:00:25:b1:34:aa:c2 Displays membership status of a port wwn. Very good if you’re concerned that 1 HBA is used in more than 1 zone!
show zone statistics Displays zone statistics.
show zone statistics read-only-zoning Displays read-only zoning statistics.
show zoneset active Displays the active zone sets.
show zoneset brief Displays brief descriptions of zone sets.
show zone active Displays the active zones.
show zone status Displays zone status.
show zone Displays zone statistics.
show running Displays the interface-based zones.

Enhance your WiFi by using beer!

Posted by on March 10, 2015 No comments
Beer can WiFi booster

Bad WiFi reception

Bad WiFi reception is one of the most common annoyances these days. Especially in residential areas where every house has at least 1 access point and each family is working hard to fill the ether with their own signals. A quick fix can solve this problem relatively easy by using an empty beer can (a soda can also works).

The aluminum of an empty beer can enhance the WiFi-signal significantly. You could buy an expensive repeater, but a beer can is immensely cheaper (and is more fun to get too). Our good friend youtube shows us this instructional video.

Step by step

  1. Go to the supermarket
  2. Buy (at least) 1 can of beer (a premium brand will do better than some random cheap brand)
  3. Empty the can (don’t throw the beer in the sink at all times! Drinking is the preferred method!)
  4. Clean the inside of the can by flushing it with some water
  5. you will need a knife or scissors to open up the can and some material to fix the empty can to your router
  6. Remove the lid, used to open the can
  7. Cut off the bottom of the can
  8. Cut off the top of the can, leaving a small piece near the old drinking opening
  9. Cut the can from top to bottom at the opposite side from the drinking opening
  10. Carefully bend the metal so it (sort of) looks like a satellite dish
  11. Place the brand new dish shaped beer can on your access point, by sticking the antenna through the old drinking opening
  12. Fix the “dish” so it doesn’t fall off

steps

This little trick should enhance the signal strength by a factor 2 or 3. This only works for access points equipped with an external antenna. For antenna-less models you could try creating a somewhat larger dish and placing the whole access point on the bigger dish, but I don’t guarantee this works. You could for example use a keg, but I doubt that you can cut it by using scissors 😉

 

Cisco releases update for its SAN switches to fix the Shellshock aka Bashbug

Posted by on November 18, 2014 No comments
Cisco MDS

Although I was triggered by a daily update I received from EMC in this knowledge base article: https://support.emc.com/kb/194669, it was Cisco who finally published an update for various firmwares that did not have a fix yet for the shellshock aka bashbug.
You can find all Release Notes on the Cisco site at http://www.cisco.com/c/en/us/support/storage-networking/mds-9000-nx-os-san-os-software/products-release-notes-list.html.
The EMC version of the Release Notes can be found here:

If you haven’t upgraded yet, I’d plan to do so in the very near future!

How to start copy to hotspare manually

Posted by on November 11, 2014 5 comments
Hard Drive

I recently had to manually invoke a hot spare in a VNX 5200, but in Unisphere the option was greyed out.

Unisphere_No-CopyToHotSpare

On the CLI the command wasn’t supported. Now what?

CopyToHotSpare_fail

According to https://support.emc.com/kb/184890 the proper command is now

naviseccli -h [ip of one SP] copytodisk [source-disk] [hot spare]

CopyToDisk_Success

Using the “getdisk” command will show you the actual rebuild has started.

Bare in mind that the way to address disks is in the format “Bus_Enclosure_Disk”, so for example 1_2_3 means disk 3 (the 4th disk) in enclosure 2 on bus 1.

In Unisphere you can actually see the progress of the rebuild:

Disk Rebuild in Unisphere

Symmetrix offers a new kind of MAXimum Virtualisation (VMAX)

Posted by on July 8, 2014 8 comments
100-200-400K

The mother of all arrays has just been given an upgrade!

Well ok, maybe EMC did not produce the mother, since it’s fair to say IBM 3390 disk subsystem came first, but since the first Symmetrix came out in the early 90s with as much as a dozen or two disks, EMC has come a long way. They set the standard when it came to enterprise storage arrays. And it wasn’t just size that mattered back then: performance was and is still the number one objective for the Symms. After the “dark ages” (roughly before the year 2000) things got serious with the DMX series in 2003. The number of disks went up and loads of cache had to make sure that performance was guaranteed. DMX1, DMX2, DMX3/4 were quite a success.

And then there was VMAX

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