There have been many a query for explanation regarding the port statistics on a Brocade SAN. The text below is my attempt at demystifying the jargons alongwith some recommended actions for each of those error stats.

Always rely on recoding the delta of each counter and not absolute values.

1. Physical layer issues, these originate at the source and can propagate through fabrics.

enc_in: This counter increments when 8b/10b encoding errors are detected within a frame. enc_in errors are always detected on the ingress port.

An ingress port is nothing but a set of buffers dedicated for receiving incoming frames.

crc_err: Indicates corruption within the frame. Always seen on ingress port but will be passed by the switch unaltered through the fabric.

enc_in and/or crc_err = Possible bad media (SFP, cable, patch panel)

Bad_eof: After a loss of synchronization error, continuous-mode alignment allows the receiver to re-establish word alignment at any point in the incoming bit stream while the receiver is operational. If such a re-alignment occurs, detection of the resulting error condition is dependant upon higher level functions (eg: invalid CRC,missing EOF) my take if you see bad_eof and crc incrementing, replace SFP a.s.a.p

too_long or too_short errors indicate an unreliable link

enc_out: 8b/10b encoding errors NOT associated with frames (IDLE, R_RDY, and various other primitives). This counter increments during speed negotiation prior to login. Locking a port to a speed supported by the end device can be used to isolate issues.

– Possible bad media (SFP, cable, patch panel)

– Can cause a performance problem due to buffer recovery

disc_c3: Class 3 frame has been discarded because it is not routable to a destination address

– Corrupted or not-online Destination ID (DID)

– Timeout exceeded (Condor ASIC hold time exceeded)

– Counter may increment when FC nodes and/or switches rapidly transition between online and offline; look at fabriclog –s output

2. Link errors point to point - do not traverse fabric.

Link failures - error conditions that cause a port to drop out of an active state

– Requires the reconnecting device to FLOGI back into fabric (No speed negotiation required, since the device does not lose synchronization)

Loss of sync - occur when bit and word synchronization on link is lost

Loss of signal – occur when light or an electrical signal is lost on a link

– Require connected device to renegotiate speed and FLOGI back into fabric

If you experience device connectivity and/or performance issues and rising link counters look for

– bad cables/SFPs/patch-panel connections

– repeating cycles of online/offline states in fabriclog -s output

Once you identify the suspects use, portstats64show and portstatsshow to zero down on the culprit.

If you see errors on an ISL port and want to determine if source of dest is causing the error,

To find out if source or destination SFP is causing the error, Check the Output of "portshow x" where x is the port number.

If the pair of "Lr_in " and "Ols_out " as well the "Lr_out " and "Ols_in " values are "quite" equal, it is a normal case.

If one counter is significantly higher than the other, the link problems either "reached" the switch ("in" > "out") or are caused by the switch ("out" > "in").

Note: If the “Ols_in ? value is higher than the “Lr_out ? one, then the “problem source? is, in most cases, more related to the attached device (sending those offline sequences) and the switch responds to them with a "link reset".

The concept initially sounded like a freelance website to me. A few minutes into reading it, I was shocked, human workforce in the cloud. All I can think at the moment is, what next?? Car's in the cloud??

Here's all that I understood about the concept of a Mechanical Turk.

Mechanical Turk or Mturk is an online marketplace for work.

You can either be a mechanical turk worker or a mechanical turk requester.

A worker is someone who is looking to earn money by utilizing a few hours of his/her spare time.

A requester is someone who posts HITs - Human Intelligence tasks on the Mturk website and pays for the work done. He can do this manually or using an API.

If it was done manually then there wouldn't have been much difference between a freelance website like ELANCE and MTURKs. But here you can choose to code your application to integrate with Mturks. You can integrate the available API's to automate turk selection, and also to automatically reward the response based on embedded intelligence. For example if 2 or more responses match the criterion, then automate payout. A sample use of the API

read (photo);
photoContainsHuman = callMechanicalTurk(photo);
if (photoContainsHuman == TRUE){
    acceptPhoto;
}
else {
    rejectPhoto;
}

A sample HIT request is as follows

Requester:  
Bill S. Preston, Esq.
HIT Expiration Date:  
Apr 8, 2010  (5 days 15 hours)
Time Allotted:  
3 days 11 hours
Reward:  
$4.00
HITs Available:  
4

Description:
Go find a specialize location near you and let us know what is there.
Keywords:
mobmerge,  builder,  dolores,  labs,  crowd,  flower,  crowdflower,  doloreslabs,  deloreslabs,  delores

Qualifications Required:
Your Value
 
Location is IN
IN
You meet this qualification requirement

Good news for housewives in India and other countries?? Well not so. At this time the payout is available only to US Citizens or people with Bank accounts in USA.

Good news is that you can get a feel of the service with the Mturks Sandbox

Gartner predicts that Indian IT services will see double digit growth this year. It predicts around 20% growth for the industry which is a positive sign.

http://business.rediff.com/report/2010/feb/08/tech-indian-it-services-will-see-double-digit-growth-soon.htm

Unbeleivable right...! Well if I were a customer, I would be too. But its true, CoPar Systems and Techhelp24 have signed up a partnership agreement to make this customer dream a reality.

Some questions that the clients are asking me as they begin to hear this news.

What do you provide for 99 USD a month??

We provide remote help to any escalation from your storage admin at any tme of the day or week. The help could be over phone, or via a remote control of your admins desktop. We have a network of experts around the world and also our own Labs where we test our own procedures and also the latest firmware.

And before you engage us, we will perform an assessment and make sure that we are able to support all the equipment in your environment. You can also request for a 1 month free trial if you are unsure.

How does this service benefit you if you already have vendor support??

Most times you need help to carry out your day to day tasks which do not qualify as a support call. For example you would want to check the implications of downloading a particular firmware on your switch. Now your vendor would provide you the software compatibility matrix and ask you to figure it out yourself. If you really need them involved then you would have to engage them in consulting or onsite services for a additional fee, which would not be easy on your pocket.

With ESSS we offer you a No Frills service and will try help you all the way in any case you like. For our experts who would have already handled similiar cases this would be relatively easier than you administrator who is probably performing the task for the first time.

Is this a proven support model??

Oh yes. We have over 50 clients with more set to join in the coming months. We have government agencies, educational institutions, SME's and even some large organisations on our client list.

Can this service be extended to onsite support and project specific tasks??

Yes. Although CoPar Systems is a relatively new company, our service partner network is one of the best in the world. So if you want to switch over from expensive vendor agreements to our global break fix and support service, just let us know, and our rates are surely gonna baffle you. So you do not need to worry about pulling out services out from your regular vendor just because you need to ensure his future involvement in onsite activities.

How can you deliver these services at such a low rate??

The answer is simple we have mastered the art of minimizing our overheads. So even though we have similiar delivery capabilities as other vendors, we have kept our operations simple and low key. To lower costs we have partnered with companies around the world and created an ecosystem that benefits all.

Also the fact that ESSS is aimed at remote support and extended support for your administrators, helping us to reduce overheads further. Remote support capabilities can help our consultant in Germany serve a client in Malaysia, thus helping us create a pool of experts will less OPEX.

So who will benefit the most from this service??

We definitely cannot serve very large companies @ 99 USD a month, but there are plenty of organisations who can gain tremendous benefit from this. Examples of such organisations are

1. Small and midsized Government agencies
2. Educational Institutions
3. SME's
4. Branch Offices
5. Small divisions of Large corporates
6. System Integrators

If you would like to know if you qualify for ESSS, its quite simple, contact us via our online form and provide us your requirements. We will get back to you in less than 24 hours.

Traditionally migrations have been categorized into 2 categories

• Server Migrations
• Storage Migrations

In my experience I have never seen a single vendor or team tackle DC migrations with a unified approach. Most vendors treat the above 2 categories differently, creating complexities and overheads for the customer.

A few years ago, I remember co-ordinating a DC migration, and we were only in charge of storage migration. The client was asked to migrate the servers and workload all by himself. This was due to the fact that we were awarded the Storage migration project only. I still remember the amount of co-ordination the customer focal point had to undertake to make this a success.

Now at CoPar Systems, we would like you to take a back seat while we migrate both your workloads as well as storage. The approach has been briefly described in the attached document (free for download). We use 2 revolutionary technologies and combine them into an innovative solution, specifically designed to make DC migrations simple and seamless.

The document covers the techniques and tools used in each phase, as well strategies to minimize TCO and reuse hardware. It also has a section describing the resource requirements for such projects, in case you want to try this on your own.

Download our solution brief here - Migrating Data Centers.

Migrating Data Centers - by CoPar systems .pdf