How To Succeed In Presales?


This article is aimed at anyone considering making the move into technical presales who currently works in a professional services, consultancy or support role, or as customers and end-users. You will notice that the title of the article has a question mark at the end – that’s because I don’t have the answer – and I have neither the confidence nor the evidence to claim that I have been a success. But I have made lots of mistakes… and apparently you can learn from those, so here I will share some of my experiences of making the leap. I’d also like to point out that after two years working in presales for Violin Memory I haven’t – yet – been fired, which I believe is a good sign.

My first day at Violin Memory was a disaster. In fact, let me be more specific, it was my first hour. Having spent my career working variously as in development, as a consultant for an Oracle partner, an Oracle customer and then in professional services for Oracle itself, I’d finally taken the leap into technical presales and this was to be my first day. Sure I’d done bits and pieces of presales work before, but this was a proper out-and-out presales role – and I knew that I was either going to sink or swim. Within the first hour I was deep underwater.

Someone doing a much better job than me

Someone doing a much better job than me

By a quirk of timing, it turned out that my first day at Violin was actually the first day of the annual sales conference held in silicon valley. So the day before I’d boarded a plane with a number of other fresh recruits (all veterans of sales organisations) and flown to San Francisco where, in the true spirit of any Englishman abroad, I’d set about using alcohol as a tool to combat jet lag. Smart move.

It’s not as if I didn’t know what a mistake this was. I’d learnt the same lesson on countless other occasions in my career – that having a hangover is painful, unprofessional and deeply unimpressive to those unfortunate enough to meet you the following morning – but maybe my attempts to integrate with my new team were a little bit over-enthusiastic. Meanwhile, my new boss (the one who had taken the gamble of employing me) had asked me to prepare a presentation which would be delivered to the team at some point on day 1.

Day 1 arrived – and at 8.00am we gathered in a conference room to see the agenda. Guess who was up first? At 8.05am I stood up, hungover, unprepared, very nervous and (give me a break, I’m looking for excuses) jet-lagged to deliver… well if it wasn’t the worst presentation of my life, it was in the top two (I have previously mentioned the other one here). I mumbled, I didn’t look for feedback from the audience, I talked too fast for the non-native English speakers in the room and my content was too technical. I’m surprised they didn’t pack me off to the airport right then. It was not a success.

And Yet…

The thing is, the subject of my talk was databases. As anyone who knows me can attest (to their misfortune), I love talking about databases. It’s a subject I am passionate about and, if you get me started, you may have trouble stopping me. This is because to me, talking about database is just as much fun as actually using them, but much easier and with less need to remember the exact syntax. So why did I choke that day – the worst possible day to make a bad impression?

unpreparedThere is an obvious moral to my tale, which is not to be so stupid. Don’t turn up unprepared, do make sure your content is at the right level and don’t drink too much the night before. Follow those rules and you’ll be confident and enthusiastic instead of nervous and monotonous. But you know this and I didn’t tell this sorry tale just to deliver such a lame piece of advice.

One of the enduring myths about working in sales is that it’s all about delivering presentations – and this sometimes puts people off, since many have little presentation experience nor an easy way of gaining it. While it’s true that being able to present and articulate ideas or solutions is an essential part of any sales role (I wouldn’t recommend presales if you actively dislike presenting), in the last two years I’ve come to the conclusion that there are more important qualities required. In my opinion the single most important skill needed to work in presales is the ability to become a trusted advisor to your (potential) customers. People buy from people they trust. If you want to help sell, you don’t need to impress people with your flair, style or smart suit (not that those things won’t help)… you need to earn their trust. And if you deliver on that trust, not only will they buy from you, they will come back again for more.

If you work (successfully) in professional services or consultancy right now, the chances are you already do this. Your customers won’t value your contribution unless they trust you. Likewise if you work for a customer or end-user, it’s quite likely that you have internal customers (e.g. the “business” that your team supports) and if you’ve gained their trust, you’re already selling something: yourself, your skills and the service you provide.

beerIt’s not for everybody, but I find working in technical presales hugely fulfilling. I get to meet lots of interesting customers, see how they run their I.T. organisations and services, talk to them about existing and future technologies and I get to experience the highs (and lows) of winning (or not winning) deals.

If you’re thinking of making the move, don’t be put off by concerns over a lack of sales experience. You may not be aware, but the chances are, you already have it. Just don’t drink too much the night before your first day…

The Ultimate Guide To Oracle with Advanced Format 4k


It’s a brave thing, calling something the “Ultimate Guide To …” as it can leave you open to criticism that it’s anything but. However, this topic – of how Oracle runs on Advanced Format storage systems and which choices have which consequences – is one I’ve been learning for two years now, so this really is everything I know. And from my desperate searching of the internet, plus discussions with people who are usually much knowledgeable than me, I’ve come to the conclusion that nobody else really understands it.

In fact, you could say that it’s a topic full of confusion – and if you browsed the support notes on My Oracle Support you’d definitely come to that conclusion. Part of that confusion is unfortunately FUD, spread by storage vendors who do not (yet) support Advanced Format and therefore benefit from scaring customers away from it. Be under no illusions, with the likes of Western DigitalHGST and Seagate all signed up to Advanced Format, plus Violin Memory and EMC’s XtremIO both using it, it’s something you should embrace rather than avoid.

However, to try and lessen the opportunity for those competitors to point and say “Look how complicated it is!”, I’ve split my previous knowledge repository into two: a high-level page and an Oracle on 4k deep dive. It’s taken me years to work all this stuff out – and days to write it all down, so I sincerely hope it saves someone else a lot of time and effort…!

Advanced Format with 4k Sectors

Advanced Format: Oracle on 4k Deep Dive

A New Approach To My Blogroll

Like most people, I have a panel on the right hand side of my blog which contains my blogroll, i.e. a list of links to the blogs of other people I respect and admire. And like most people in the Oracle world, up until today it was full of the same names you always see. To pick three examples:

Tanel Poder – One of the most interesting and entertaining Oracle experts around, someone you should definitely see present (and drink beer with)

Jonathan Lewis – Another legendary Oracle guru who literally wrote the book on the subject. If you haven’t read this, you should.

Cary Millsap – One of my favourites, whose articles are always more than just interesting – they are thought-provoking.

So why are these names no longer on my list? It’s not due to a lack of respect on my part, since I admire these guys enormously. It’s just because, well… everyone knows them already. What’s the point of linking to people when everyone already knows them, follows them, reads their stuff and learns from them every day?

So from today, I’m going to adopt a new approach to my blogroll, which is to limit it to just three groups of links:

  • Violin Memory-related links, such as the corporate website and the blogs of my colleagues
  • Storage-industry-related blogs from competitors of Violin who I admire and respect
  • The blogs of less-well-known members of the Oracle community that I think are just as admirable and useful as the legends I mentioned above

If you are one of the names in the last list, please don’t take the phrase “less-well-known” as an insult! Everyone is less-well-known than Tanel, after all. And if you aren’t on the list, well – now you don’t need to feel aggrieved, because it obviously means you are just too popular to make the grade!


New installation cookbook for SUSE Linux Enterprise Server 11 SP3

Exactly what it says on the tin, I’ve added a new installation cookbook for SUSE 11 SP3 which creates Violin on a set of 4k devices.

I’ve started setting the add_random tunable of the noop I/O scheduler because it seems to give a boost in performance during benchmarking runs. If I can find the time, I will blog about this at some point…

For more details read this document from Red Hat.

Postcards from Storageland: Two Years Flash By


The start of March means I have been working at Violin Memory for exactly two years. This also corresponds to exactly two years of the flashdba blog, so I thought I’d take stock and look at what’s happened since I embarked on my journey into the world of storage. Quite a lot, as it happens…

Flash Is No Longer The Future

The single biggest difference between now and the world of storage I entered two years ago is that flash memory is no longer an unknown. In early 2012 I used to visit customers and talk about one thing: disk. I would tell them about the mechanical limitations of disk, about random versus sequential I/O, about how disk was holding them back. Sure I would discuss flash too – I’d attempt to illustrate the enormous benefits it brings in terms of performance, cost and environmental benefits (power, cooling, real estate etc)… but it was all described in relation to disk. Flash was a future technology and I was attempting to bring it into the present.

Today, we hardly ever talk disk. Everyone knows the limitations of mechanical storage and very few customers ever compare us against disk-based solutions. These days customers are buying flash systems and the only choice they want to make is over which vendor to use.

Violin Memory 2.0

The storage industry is awash with people who use “personal” blogs as a corporate marketing mouthpiece to trumpet their products and trash the competition. I always avoid that, because I think it’s insulting to the reader’s intelligence; the point of blogging is to share knowledge and personal opinion. I also try to avoid talking about corporate topics such as roadmap, financial performance, management changes etc. But if I wrote an article looking back at two years of Violin Memory and didn’t even mention the IPO, all credibility would be gone.

So let me be honest [please note the disclaimer, these are my personal opinions), the Violin Memory journey over the last couple of years has been pretty crazy. We have such a great product – and the flash market is such a great opportunity – that the wave of negative press last year came as a surprise to me. I guess that shows some naivety on my part for forgetting that product and opportunity are only two pieces of the puzzle, but all the same what I read in the news didn’t seem to correspond to what I saw in my day job as we successfully competed for business around Europe. I had customers who had not just improved but transformed their businesses by using Violin. That had to be a good sign, right?

Now here we are in 2014 and, despite some changes, Violin continues to develop as a company under the guidance of an experienced new CEO. I’m still doing what I love, which is travelling around Europe (in the last month alone I’ve been in the UK, France, Switzerland, Turkey and Germany) meeting exciting new customers and competing against the biggest names in storage (see below). In a world where things change all the time, I’m happy to say this is one thing that remains constant.

The Competition

Now for the juicy bit. Part of the reason I was invited to join Violin was to compete against my former employer’s Exadata product – something I have been doing ever since. However, in those heady days of 2011 it also appeared that Fusion IO would be the big competitor in the flash space. Meanwhile, at that time, none of the big boys had flash array products of note. EMC, IBM, NetApp, Cisco, Dell… nothing. The only one who did was HP, who were busy reselling a product called VMA – yes that’s right, the Violin Memory Array – despite having recently paid $2.4b for 3PAR.

Then everything seemed to happen at once. EMC paid an astonishing amount of money for the “pre-product” XtremIO, which took 18 months to achieve general availability. IBM bought the struggling Texas Memory Systems. HP decided to focus on 3PAR over Violin. Cisco surprised everyone by buying Whiptail (including themselves, apparently). And NetApp finally admitted that their strategy of ignoring flash arrays may not have been such a good idea.

That’s the market, but what have I seen? I regularly compete against other flash vendors in the EMEA region – and don’t forget, I only get involved if it’s an Oracle database solution under consideration. The Oracle deals tend to be the largest by size and occupy a space which you could clearly describe as “enterprise class” – I rarely get involved in midrange or small business-sized deals.

The truth is I see the same thing pretty much every time: I compete against EMC and IBM, or I compete against Oracle Exadata. I’ve never seen Fusion IO in a deal – which is not surprising because their cards and our arrays tend to be solutions for different problems. However, I’ve also never – ever – seen Pure Storage in a competitive situation on one of my accounts, nor Nimbus, Nimble, SolidFire, Kaminario or Skyera. I’ve seen Whiptail, HDS and Huawei maybe once each; HP probably a few more times. But when it comes down to the final bake off, it’s EMC, IBM or Exadata. I claim that my experience is representative of the market, but it is real.

Who is the biggest threat? That’s an easy one to answer: it’s always the incumbent storage supplier. No matter how great a solution you have, or how low a price, it’s always easier for a customer to do nothing than to make a change. Inertia is our biggest competitor. Yet at the same time the incumbent has the biggest problem: so much to lose.

And how am I doing in these competitions? Well, that would be telling. But look at it this way – two years on and I’m still trusted to do this.

I wonder what the next two years will bring?

More Problems with Oracle’s Support of 4k Devices

This is going to be another one of those posts, a bit like this one, that discuss the use of Oracle’s database product with Advanced Format devices. I wish there weren’t so many of these posts, but it seems that Oracle has a lot of issues with it’s implementation of 4k support.

(Before reading on, if you aren’t sure what I’m talking about here then please have a read of this page…)

In the last post I built a database which used Oracle ASM (and the Linux ASMLib kernel driver) but found that if the database used an SPFILE which was located on a 4k device (within an ASM diskgroup) it didn’t work. Today, I’m going to forego ASM and use a filesystem instead (something I would never do in real life).

Building a 4k Filesystem

Let’s start with a single 4k LUN being presented from my Violin array. I’ve already configured the Linux device mapper multipathing so that it presents itself as a nicely-named device in the /dev/mapper directory:

[oracle@half-server4 ~]$ ls -l /dev/mapper/fs4ktest 
lrwxrwxrwx 1 root root 7 Feb 25 15:53 /dev/mapper/fs4ktest -> ../dm-7
[oracle@half-server4 ~]$ fdisk -l /dev/mapper/fs4ktest

Note: sector size is 4096 (not 512)

Disk /dev/mapper/fs4ktest: 215.8 GB, 215822106624 bytes
255 heads, 63 sectors/track, 3279 cylinders
Units = cylinders of 16065 * 4096 = 65802240 bytes
Sector size (logical/physical): 4096 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 524288 bytes

We can see that this is indeed a 4k device, i.e. it has not only a 4096 byte physical blocksize, but a 4096 byte logical blocksize too. The fdisk command has even taken the time to print a special “Note” to ensure we see the sector size is not the usual 512 bytes. The next thing to do is format it with a filesystem so I’m going to use ext4:

[root@half-server4 ~]# mkfs.ext4 /dev/mapper/fs4test 
mke2fs 1.41.12 (17-May-2010)
Filesystem label=
OS type: Linux
Block size=4096 (log=2)
Fragment size=4096 (log=2)
Stride=1 blocks, Stripe width=128 blocks
2097152 inodes, 8388608 blocks
419430 blocks (5.00%) reserved for the super user
First data block=0
Maximum filesystem blocks=4294967296
256 block groups
32768 blocks per group, 32768 fragments per group
8192 inodes per group
Superblock backups stored on blocks: 
	32768, 98304, 163840, 229376, 294912, 819200, 884736, 1605632, 2654208, 
	4096000, 7962624

Writing inode tables: done                            
Creating journal (32768 blocks): done
Writing superblocks and filesystem accounting information: done

Now it needs to be mounted. I’m just going to stick it on a mount point in a new top-level directory called /fstest:

[root@half-server4 ~]# mkdir -p /fstest/fs4ktest
[root@half-server4 ~]# chown -R oracle:oinstall /fstest
[root@half-server4 ~]# mount /dev/mapper/fs4ktest /fstest/fs4ktest

Finally, we I am going to create an Oracle database using this filesystem. I’m not going to cut and paste all the output for that, because it’s all a bit dull… so let’s just skip to the bit where DBCA has completed and the database is open.

Oracle On A 4k Filesystem

So the good news is, it worked. The database is up and running and the datafiles are located on the 4k filesystem:

[oracle@half-server4 fstest]$ sqlplus / as sysdba

SQL*Plus: Release Production on Mon Mar 3 21:30:02 2014
Copyright (c) 1982, 2013, Oracle.  All rights reserved.

Connected to:
Oracle Database 12c Enterprise Edition Release - 64bit Production
With the Partitioning, OLAP, Advanced Analytics and Real Application Testing options

SQL> select name from v$datafile;


Cool. We can end this post here then, right? Well, no… because there is a bit of a problem with this database. Let’s just have a quick check of the FILESYSTEMIO_OPTIONS parameter:

SQL> show parameter filesystem

------------------------------------ ----------- ------------------------------
filesystemio_options		     string	 none

This parameter controls the way that I/O is performed for files located on filesystems. It isn’t relevant for databases using Oracle ASM (for which the DISK_ASYNCH_IO parameter exists instead), but here it’s making a massive difference. According to the Oracle documentation, it has four possible options:

  • ASYNCH: enable asynchronous I/O on file system files, which has no timing requirement for transmission.
  • DIRECTIO: enable direct I/O on file system files, which bypasses the buffer cache.
  • SETALL: enable both asynchronous and direct I/O on file system files.
  • NONE: disable both asynchronous and direct I/O on file system files.

Normally, when I see filesystem-based databases, I find this parameter set to SETALL. This means asynchronous and direct I/O, but here it is set to NONE which means neither. And it’s the DIRECTIO that we are interested in.

One Buffer Cache Is Enough

As you are no doubt aware, Oracle databases have a buffer cache which is used to cache copies of database blocks. However, the Linux operating system also has its own buffer cache for filesystems. Most people would consider it ineffective to use two levels of cache – and if that is the case, it will obviously be the Oracle buffer cache that needs to be used. So let’s set the parameter to use direct I/O and then restart the database (as the parameter is not dynamic):

SQL> alter system set filesystemio_options='directIO' scope=spfile;

System altered.

SQL> shutdown immediate
Database closed.
Database dismounted.
ORACLE instance shut down.
SQL> startup
ORACLE instance started.

Total System Global Area 1.3896E+10 bytes
Fixed Size		    4663568 bytes
Variable Size		 2751465200 bytes
Database Buffers	 1.1107E+10 bytes
Redo Buffers		   33673216 bytes
ORA-00205: error in identifying control file, check alert log for more info

Oh dear. What happened?

[oracle@half-server4 ~]$ tail /u01/app/oracle/diag/rdbms/fstest/fstest/trace/alert_fstest.log 
ORA-00210: cannot open the specified control file
ORA-00202: control file: '/fstest/fs4ktest/oracle/oradata/FSTEST/controlfile/o1_mf_9k9wzp31_.ctl'
ORA-27047: unable to read the header block of file
Linux-x86_64 Error: 22: Invalid argument
Additional information: 1
ORA-205 signalled during: ALTER DATABASE   MOUNT...

The answer, which you can find in My Oracle Support note 1133713.1, is that Oracle does not support 4k devices with direct I/O. This has been the case for a long time – I remember first discovering this nearly two years ago, on, yet there is no sign of it being fixed. According to the note, “It is not yet known in which version this support will be available.” Pah.

There’s More: Diagnostic Destination on 4k

And then there’s the diagnostic destination. How about if I choose to locate this on a 4k filesystem?

SQL> show parameter diagnostic_dest

------------------------------------ ----------- ------------------------------
diagnostic_dest 		     string	 /u01/app/oracle

SQL> alter system set diagnostic_dest='/fstest/fs4ktest/oracle' scope=spfile;

System altered.

I’ll give it a few minutes and then go and look in some of the files… guess what I see?

ORA-48101: error encountered when attempting to read a file [block] [/fstest/fs4ktest/oracle/diag/rdbms/fstest/fstest/metadata/INCIDENT.ams] [0]
ORA-27072: File I/O error
Linux-x86_64 Error: 22: Invalid argument
Additional information: 4
Additional information: 1
Additional information: -1

Look familiar? (This is nothing to do with direct I/O by the way, I disabled that again before this test.)

So let’s be honest, things aren’t going all that well here. There are still a lot of things that do not appear to work properly when using 4k devices. Luckily, my Violin array can present storage as 512 byte to avoid this sort of issue, but really I feel that Oracle needs to get cracking on its Advanced Format support. This is not just a flash memory thing, pretty much every major disk vendor is making Advanced Format devices now from Western Digital, through HGST to Seagate.

Time to get with the programme?

Oracle ASMLib: Physical and Logical Blocksize

This article is about the use of Advanced Format devices on Oracle’s ASMLib kernel library for Linux. For background, read this page on 4k sector sizes first, otherwise it might all sound like nonsense. Mind you, it mind sound like nonsense anyway, I can’t guarantee anything here. By the way, a big hello to my buddy Nate who asked for this information: you rock, dude.

In more recent versions of ASMLib, Oracle introduced a new parameter into the /etc/sysconfig/oracleasm file:

[root@half-server4 mapper]# tail -5 /etc/sysconfig/oracleasm
# ORACLEASM_USE_LOGICAL_BLOCK_SIZE: 'true' means use the logical block size
# reported by the underlying disk instead of the physical. The default
# is 'false'

To understand what this parameter does, consider this device which I am presenting from a Violin array:

[root@half-server4 ~]# ls -l /dev/mapper/testlun
lrwxrwxrwx 1 root root 8 Feb 27 15:33 /dev/mapper/testlun -> ../dm-19
[root@half-server4 ~]# fdisk -l /dev/mapper/testlun

Disk /dev/mapper/testlun: 34.4 GB, 34359738368 bytes
255 heads, 63 sectors/track, 4177 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Sector size (logical/physical): 512 bytes / 4096 bytes
I/O size (minimum/optimal): 4096 bytes / 524288 bytes

The important bit there is highlighted in red. This device has a 4k physical blocksize (as all Violin devices do, as well as many other modern storage systems) but has a 512 byte logical blocksize. Essentially, this LUN is pretending to be a 512 byte based.

Now that’s all well and good. Operating systems and applications that cannot support 4k block sizes (e.g. Red Hat 5 and Oracle Linux 5) will happily use this, because they believe it to be 512 byte. But later versions of ASMLib have started being too clever for their own good.

Don’t Look Behind The Curtain

Let’s create an ASMLib label on this device:

root@half-server4 ~]# oracleasm createdisk TESTLUN /dev/mapper/testlun 
Writing disk header: done
Instantiating disk: done

And now we can attempt to put an ASM diskgroup on it:

     'compatible.asm' = '11.2',
     'compatible.rdbms' = '11.2';  
ERROR at line 1:
ORA-15018: diskgroup cannot be created
ORA-15038: disk '' mismatch on 'Sector Size' with target disk group [4096]

What happened? Well, ASMLib has looked behind the smoke and mirrors and decided that this is actually a 4k device. It’s therefore presenting this to Oracle ASM as 4k, which causes the problem (because I explicitly asked for sector size to be 512 byte on this diskgroup).

One possible solution is to change the ASM_DISKSTRING from it’s default value of NULL (meaning ‘ORCL:*’) to ‘/dev/oracleasm/disks/*’, i.e. the location where ASMLib creates its own block devices. We can test this theory with fdisk:

[oracle@half-server4 ~]$ ls -l /dev/oracleasm/disks/TESTLUN 
brw-rw---- 1 oracle dba 252, 19 Feb 27 15:38 /dev/oracleasm/disks/TESTLUN
[oracle@half-server4 ~]$ fdisk -l /dev/oracleasm/disks/TESTLUN | grep "Sector size"
Sector size (logical/physical): 512 bytes / 4096 bytes

So that would work. But it would lose many of the claimed benefits of ASMLib such as reduced file descriptors and context switching. Also, it feels like a hack.


The answer, as you probably guessed, is to set this new parameter. It defaults, wrongly in my opinion, to using the physical block size. We can either edit the value in the file to be true in order to use the logical blocksize, or preferably use the oracleasm configure command:

root@half-server4 ~]# oracleasm configure -b
Writing Oracle ASM library driver configuration: done
[root@half-server4 ~]# oracleasm configure | grep ORACLEASM_USE_LOGICAL_BLOCK_SIZE

It can be set back to using the physical blocksize with the following command:

[root@half-server4 ~]# oracleasm configure -p
Writing Oracle ASM library driver configuration: done
[root@half-server4 ~]# oracleasm configure | grep ORACLEASM_USE_LOGICAL_BLOCK_SIZE

Finally, a word of warning. If you are like me, then you are a bit stupid and can’t follow instructions properly. I set the value of the parameter to TRUE in upper case and then spent hours wondering why it didn’t work. The answer, to my embarrassment, is that it’s case sensitive. TRUE is not a valid value so it defaults to false. Doh.


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