It’s all about delivering value to the end user. If one can deliver equivalent value with commodity hardware than possible with special purpose hardware then obviously commodity hardware wins – no question about it.
But, and it’s a big BUT, when some company invests in special purpose hardware, they have an opportunity to deliver better value to their customers. Yes it’s going to be more expensive on a per unit basis but that doesn’t mean it can’t deliver commensurate benefits to offset that cost disadvantage.
Look around, one sees special purpose hardware everywhere. For example, just checkout Apple’s iPad, iPhone, and iPod just to name a few. None of these would be possible without special, non-commodity hardware. Yes, if one disassembles these products, you may find some commodity chips, but I venture, the majority of the componentry is special purpose, one-off designs that aren’t readily purchase-able from any chip vendor. And the benefits it brings, aside from the coolness factor, is significant miniaturization with advanced functionality. The popularity of these products proves my point entirely – value sells and special purpose hardware adds significant value.
One may argue that the storage industry doesn’t need such radical miniaturization. I disagree of course, but even so, there are other more pressing concerns worthy of hardware specialization, such as reduced power and cooling, increased data density and higher IO performance, to name just a few. Can some of this be delivered with SBB and other mass-produced hardware designs, perhaps. But I believe that with judicious selection of special purposed hardware, the storage value delivered along these dimensions can be 10 times more than what can be done with commodity hardware.
Special purpose HW cost and development disadvantages denied
The other advantage to commodity hardware is the belief that it’s just easier to develop and deliver functionality in software than hardware. (I disagree, software functionality can be much harder to deliver than hardware functionality, maybe a subject for a different post). But hardware development is becoming more software like every day. Most hardware engineers do as much coding as any software engineer I know and then some.
Then there’s the cost of special purpose hardware but ASIC manufacturing is getting more commodity like every day. Several hardware design shops exist that sell off the shelf processor and other logic one can readily incorporate into an ASIC and Fabs can be found that will manufacture any ASIC design at a moderate price with reasonable volumes. And, if one doesn’t need the cost advantage of ASICs, use FPGAs and CPLDs to develop special purpose hardware with programmable logic. This will cut engineering and development lead-times considerably but will cost commensurably more than ASICs.
Do we ever stop innovating?
Probably the hardest argument to counteract is that over time, commodity hardware becomes more proficient at providing the same value as special purpose hardware. Although this may be true, products don’t have to stand still. One can continue to innovate and always increase the market delivered value for any product.
If there comes a time when further product innovation is not valued by the market than and only then, does commodity hardware win. However, chairs, cars, and buildings have all been around for many years, decades, even centuries now and innovation continues to deliver added value. I can’t see where the data storage business will be any different a century or two from now…
I was talking with another cloud storage gateway provider today and I asked them if they do any sort of backup for data sent to the cloud. His answer disturbed me – they said they depend on backend cloud storage providers replication services to provide data protection – sigh. Curtis and I have written about this before (see my Does Cloud Storage need Backup? post and Replication is not backup by W. Curtis Preston).
Cloud replication is not backup
Cloud replication is not data protection for anything but hardware failures! Much more common than hardware failures is mistakes by end-users who inadvertently delete files, overwrite files, corrupt files, or systems that corrupt files any of which would just be replicated in error throughout the cloud storage multi-verse. (In fact, cloud storage itself can lead to corruption see Eventual data consistency and cloud storage).
Replication does a nice job of covering a data center or hardware failure which leaves data at one site inaccessible but allows access to a replica of the data from another site. As far as I am concerned there’s nothing better than replication for these sorts of DR purposes but it does nothing for someone deleting the wrong file. (I one time did a “rm * *” command on a shared Unix directory – it wasn’t pretty).
Some cloud storage (backend) vendors delay the deletion of blobs/containers until sometime later as one solution to this problem. By doing this, the data “stays around” for “sometime” after being deleted and can be restored via special request to the cloud storage vendor. The only problem with this is that “sometime” is an ill-defined, nebulous concept which is not guaranteed/specified in any way. Also, depending on the “fullness” of the cloud storage, this time frame may be much shorter or longer. End-user data protection cannot depend on such a wishy-washy arrangement.
Other solutions to data protection for cloud storage
One way is to have a local backup of any data located in cloud storage. But this kind of defeats the purpose of cloud storage and has the cloud data being stored both locally (as backups) and remotely. I suppose the backup data could be sent to another cloud storage provider but someone/somewhere would need to support some sort of versioning to be able to keep multiple iterations of the data around, e.g., 90 days worth of backups. Sounds like a backup package front-ending cloud storage to me…
Another approach is to have the gateway provider supply some sort of backup internally using the very same cloud storage to hold various versions of data. As long as the user can specify how many days or versions of backups can be held this works great, as cloud replication supports availability in the face of hardware failures and multiple versions support availability in the face of finger checks/logical corruptions.
This problem can be solved in many ways, but just using cloud replication is not one of them.
Listen up folks, whenever you think about putting data in the cloud, you need to ask about backups among other things. If they say we only offer data replication provided by the cloud storage backend – go somewhere else. Trust me, there are solutions out there that really backup cloud data.
Above one can see a chart from our September SPECsfs2008 Performance Dispatch displaying the scatter plot of NFS Throughput Operations/Second vs. number of disk drives in the solution. Over the last month or so there has been a lot of Twitter traffic on the theory that benchmark results such as this and Storage Performance Council‘s SPC-1&2 are mostly a measure of the number of disk drives in a system under test and have little relation to the actual effectiveness of a system. I disagree.
As proof of my disagreement I offer the above chart. On the chart we have drawn a linear regression line (supplied by Microsoft Excel) and displayed the resultant regression equation. A couple of items to note on the chart:
Regression Coefficient – Even though there are only 37 submissions which span anywhere from 1K to over 330K NFS throughput operations a second, we do not have a perfect correlation (R**2=~0.8 not 1.0) between #disks and NFS ops.
Superior systems exist – Any of the storage systems above the linear regression line have superior effectiveness or utilization of their disk resources than systems below the line.
As one example, take a look at the two circled points on the chart.
The one above the line is from Avere Systems and is a 6-FXT 2500 node tiered NAS storage system which has internal disk cache (8-450GB SAS disks per node) and an external mass storage NFS server (24-1TB SATA disks) for data with each node having a system disk as well, totaling 79 disk drives in the solution. The Avere system was able to attain ~131.5K NFS throughput ops/sec on SPECsfs2008.
The one below the line is from Exanet Ltd., (recently purchased by Dell) and is an 8-ExaStore node clusterd NAS system which has attached storage (576-146GB SAS disks) as well as mirrored boot disks (16-73GB disks) totaling 592 disks drives in the solution. They were only able to attain ~119.6K NFS throughput ops/sec on the benchmark.
Now the two systems respective architectures were significantly different but if we just count the data drives alone, Avere Systems (with 72 data disks) was able to attain 1.8K NFS throughput ops per second per data disk spindle and Exanet (with 576 data disks) was able to attain only 0.2K NFS throughput ops per second per data disk spindle. A 9X difference in per drive performance for the same benchmark.
As far as I am concerned this definitively disproves the contention that benchmark results are dictated by the number of disk drives in the solution. Similar comparisons can be seen looking horizontally at any points with equivalent NFS throughput levels.
Rays reading: NAS system performance is driven by a number of factors and the number of disk drives is not the lone determinant of benchmark results. Indeed, one can easily see differences in performance of almost 10X on a throughput ops per second per disk spindle for NFS storage without looking very hard.
We would contend that similar results can be seen for block and CIFS storage benchmarks as well which we will cover in future posts.
The full SPECsfs2008 performance report will go up on SCI’s website next month in our dispatches directory. However, if you are interested in receiving this sooner, just subscribe by email to our free newsletter and we will send you the current issue with download instructions for this and other reports.
As always, we welcome any suggestions on how to improve our analysis of SPECsfs2008 performance information so please comment here or drop us a line.
I was talking with one large enterprise customer today and he was lamenting how poorly Oracle RMAN compressed backupsets dedupe. Apparently, non-compressed RMAN backup sets generate anywhere from 20 to 40:1 deduplication ratios but when they use RMAN backupset compression, their deduplication ratios drop down to 2:1. Given that RMAN compression probably only adds another 2:1 compression ratio then the overall data reduction becomes something ~4:1.
Zlib is pretty standard repeating strings elimination followed by Huffman coding which uses shorter bit strings to represent more frequent characters and longer bit strings to represent less frequent characters.
Bzip2 also uses Huffman coding but only after a number of other transforms such as run length encoding (changing duplicated characters to a count:character sequence), Burrows–Wheeler transform (changes data stream so that repeating characters come together), move-to-front transform (changes data stream so that all repeating character strings are moved to the front), another run length encoding step, huffman encoding, followed by another couple of steps to decrease the data length even more…
The net of all this is that a block of data that is bzip2 encoded may look significantly different if even one character is changed. Similarly, even zlib compressed data will look different with a single character insertion, but perhaps not as much. This will depend on the character and where it’s inserted but even if the new character doesn’t change the huffman encoding tree, adding a few bits to a data stream will necessarily alter its byte groupings significantly downstream from that insertion. (See huffman coding to learn more).
Deduplicating RMAN compressed backupsets
Sub-block level deduplication often depends on seeing the same sequence of data that may be skewed or shifted by one to N bytes between two data blocks. But as discussed above, with bzip2 or zlib (or any huffman encoded) compression algorithm the sequence of bytes looks distinctly different downstream from any character insertion.
One way to obtain decent deduplication rates from RMAN compressed backupsets would be to decompress the data at the dedupe appliance and then run the deduplication algorithm on it – dedupe appliance ingestion rates would suffer accordingly. Another approach is to not use RMAN compressed backupsets but the advantages of compression are very appealing such as less network bandwidth, faster backups (because they are not transferring as much data), and quicker restores.
Oracle RMAN OST
On the other hand, what might work is some form of Data Domain OST/Boost like support from Oracle RMAN which would partially deduplicate the data at the RMAN server and then send the deduplicated stream to the dedupe appliance. This would provide less network bandwidth and faster backups but may not do anything for restores. Perhaps a tradeoff worth investigating.
As for the likelihood that Oracle would make such services available to deduplicatione vendors, I would have said this was unlikely but ultimately the customers have a say here. It’s unclear why Symantec created OST but it turned out to be a money maker for them and something similar could be supported by Oracle. Once an Oracle RMAN OST-like capability was in place, it shouldn’t take much to provide Boost functionality on top of it. (Although EMC Data Domain is the only dedupe vendor that has Boost yet for OST or their own Networker Boost version.)
When I first started this post I thought that if the dedupe vendors just understood the format of the RMAN compressed backupsets they would be able to have the same dedupe ratios as seen for normal RMAN backupsets. As I investigated the compression algorithms being used I became convinced that it’s a computationally “hard” problem to extract duplicate data from RMAN compressed backupsets and ultimately would probably not be worth it.
So, if you use RMAN backupset compression, probably ought to avoid deduplicating this data for now.
Well I did take the iPad and BlueTooth (BT) keypad to a short conference a couple of weeks ago and it was a disaster unlike what I envisioned in Parts 1& 2 of this saga. It turns out that some WiFi logins don’t work with the iPad (not sure if this is “Flash” issue or not). In any event, the iPad was rendered WiFi-less during the whole conference which made for an unconnected experience to say the least (recall that I don’t own a 3G version).
The hotel used T-Mobile for their WiFi connection. I must have created my account at least 3 times and tried to log-in afterward at least 5 times (persistance occasionally pays but not this time). Each time the login screen hung and I never got in. The conference had a different WiFi supplier but it had the same problem only this time all I had to do was to sign into the service with a conference supplied SSID&password. No such luck. The hotel gave me two free WiFi card keys for T-Mobile but I can’t use them.
I even tried some of the tricks that are on the web to get around this problem but none worked. Nuts!
The blog post from hell
Of course, I didn’t plan to write a blog post at the conference but I had the time and the muse struck. So I whipped out my trusty iPhone, paired the BT keypad with the iPhone, used Notes and WordPress App (WP, available free) to create a new blog post. I power typed it into the iPhone Notes app and copied and pasted into WP’s new post window.
I was always curious how to add media to posts via the WP app but anything on the iPhone including the photo library and camera photos were accessible as new media to be added to any post. I had used my iPhone to earlier take some pictures from the conference and easily added these to the post. The WordPress app uses the more primitive editing window (not WYSIWYG) but that was ok as I didn’t have a lot of fancy text layout. What’s funny is that saving on the WP app was not the same as uploading it to my blog. And once uploaded you had to change the post status to Published to get it externally visible.
Another option would have been to use the web and update the blog post through WordPress on Safari. I can’t recall but last time when I used Safari & WordPress there were some scrolling incompatibilities (inability to scroll down into the post – flash maybe) and there were other nuisances, so I decided to try the WP app this time.
The only problem with using the iPhone & WP app to enter the post was that it was hard to check spellings and see the whole post to edit it properly. Only really got to see a couple of (short) lines at a time in the iPhone WP app window and the WP app preview was not all that useful.
Needless to say, the post was published with numerous typos, mis-spellings, grammatical faux pas, etc. (so what’s different Ray?). A few readers caught the issues and DMed me on Twitter which I picked up later that night. I tried my best to fix them but it still had problems a day later when I got to my desktop. For some unknown reason, it became my most popular post – go figure.
Using the iPhone at the conference
Of course the iPhone 4 worked fine for emails, twitter, facebook and other social media given its screen and soft keypad limitations during the conference. And I was still able to take notes with the iPad I just couldn’t send them anyplace and would have liked to insert them into the post as an outline but couldn’t be done.
There is just no way to get data out of an iPad without WiFi or 3G access. Maybe if I could take a screen shot with the iPhone and then use an OCR app to interpret it into a Notes item and then I could get the text into iPhone – but I didn’t have an OCR app at the time. Also, it smacks of a Rube Goldberg contraption.
I would say the WP app on the iPad looks a lot better than the one on the iPhone but much of that is due to the increased screen space. If everything was working fine I probably wouldn’t have had as many problems using iPad WP app to enter in the post. Of course I would have had to mail the photos from the iPhone to the iPad to enter them into the post but this is standard practice with the iPad…
There’s another conference coming up (it’s conference season here in the US) and I am NOT taking the iPad. Too bad, my back hurts already just thinking about it. I foresee either a 3G iPad or the Mac Air laptop sometime in my near future but for now on it’s lugging laptops.
Just not sure if I shouldn’t take the BT keypad to take notes on the iPhone!?
PS. Saw Rob Peglar and he had a Verizon Dongle that provided a local WiFi for his iPad and 4 other “close” friends. Maybe that’s what I should invest in?
We had discussed using the iPad in a prior post and although, it was uncertain up to the last minute, I ended up taking the iPad to a conference early this month. My uncertainty was all related to getting our monthly newsletter out.
The newsletter is mainly a text file but it links to a number of Storage Intelligence (StorInt(tm) reports) PDFs which reside on my website. Creating and editing these documents is done using Microsoft Word. Oftentimes the edits to these documents involve tracked changes which aren’t handled very well by iPad’s Pages app (they’re all accepted).
In addition, these .DOC files are converted to .PDFs and uploaded to the website. While Pages handles importing Doc files and publishing PDF files from them, I am still unclear how to upload a Pages PDF file to a website. There are many FTP apps for the iPad/iPhone but none seem able to upload a PDF file out of Pages App.
All this was going to require the use of a laptop but I finally got all the file edits in and before I left, was able to send out the newsletter.
While at the conference I noticed that there really isn’t a proper Twitter client for the iPad. Most desktop/laptop Twitter clients allow one to see their Twitter stream while composing a Tweet. But the free Twitter/TweetDeck/Twitteriffic Apps on the iPad all seem to want to obscure the Twitter stream(s) when one enter’s a new tweet – probably assuming one’s using the soft keypad which would obscure the stream anyway. Nonetheless, such actions make responding to Twitter queries more difficult than necessary.
As always, loading up my current working set (client information, office doc’s, PDFs, etc.) was cumbersome. I have taken to using a special email address, only used for this purpose and creating one email per client which works alright.
Working on a project with iPad Pages App worked ok, but:
The font/special characters changes between .Doc and Pages files seems awkward. For example, I was using the large bullet on Pages and when I transformed this file to a DOC file, the bullet became HUGE.
Also the font that Pages uses defaults to something different than Microsoft Word’s defaults.
Watermark images didn’t seem to be as transparent when converting between Doc’s and Pages
Mostly these were nuisances that I had to deal with when importing a file from iPad to desktop or vice versa.
However, working on one project I realized I needed some metrics I normally keep in a spreadsheet on my desktop/laptop. I ended up calling home office and walking my associate through accessing the information and telling me what I needed to know. I also asked them to send that spreadsheet to me so that I would have it for future reference.
At the conference I was blessed with a table to sit at during the keynotes (passing myself off as a blogger) which made using the BlueTooth (BT) keypad and iPad much easier. I also used the combination on the airplane on the way home and found the combination much more flexible than a laptop. Although it’s unclear whether this would work as well sitting on my lap in normal conference seating.
Also I really wish there was some sort of other indicators/light(s) on the BT keypad. It only has one green led and this makes for rather limited communications. I tried to connect it to the iPad on the plane ride out but it failed. I thought perhaps the batteries had run down and needed to be replaced. When I got to my destination I tried again after looking up what the BT keypad green led and it worked just fine. FYI:
A flashing green led means the BT keypad is pairing with a target devicep
To turn the BT keypad on, push and hold the side button until the green led starts to blink.
To turn the BT keypad off, push and hold the side button until the green led comes on and eventually off.
For some reason this was difficult to find online but it was probably in the printed doc that came with the keyboard (filed away and never seen again). More lights might help, like green for on/yellow for discoverable, red for (going) off. Or maybe if I just need to use it more often. I may have tried to pair it with my iPhone which didn’t help (can’t be sure, also unclear how to clear it’s prior pairing).
Nevertheless, it might make sense to carry some extra batteries and/or their battery charger for just these types of problems. There were quite a few people who commented on the BT keyboard/iPad combination. They seemed unaware that it could be used with the iPad
The other problem I had was with the iPad’s spell checker. It turns out there are two levels of spell checking in the iPad and they are both active within Pages. One can be disabled at the Pages Tools=>Check Spelling and the other is under iPad settings at General=>Keyboard=>Auto-Correction. I was able to quickly find the Pages version but it took some effort to uncover the Keyboard one.
Nonetheless, while pounding in conference notes, I often employ vendor acronyms. Oftentimes the spell checker/auto-corrector would transform these acronyms to something completely different. Of course my typing is not perfect, so my other issue is that I miss-type words, which after auto-correction had little relation to what I was trying to type.
I realize that this is an attribute of soft keypad corrections, probably coming from the iPhone where often people mis-type due to the size of the keys. However, when using the iPad and especially when using the BT keypad it would be nice if auto-correction was turned off, by default.
Other iPad incredulity
I was surprised to see some analysts with both an iPad and a laptop (and probably an iPhone/Blackberry). Personally, I can’t see why anyone would want both other than for more screen space. But I was a bit jealous when I had to change Apps to tweet something or check email/websites while inputing notes in real time.
Also, I was afraid depending on hotel/conference WIFI would place me at a disadvantage to other analysts/bloggers. Ultimately, I found that for my use of internet (mostly for Twitter and email) during conferences, WIFI was adequate and I always had my iPhone if it didn’t work.
After 2hrs+ of keynotes and another 2hrs+ of presentations, I was running low on iPad power. So, I started to power the iPad off between notes and tweets. Funny thing, all I had to do to power on the screen was to start typing on the BT keypad – cool. As I recall, it occasionally missed the first key stroke or so but worked fine after that. Following lunch about an hour later, I pulled out my power cord extension and plugged it into the table outlet and kept it on for the rest of the day. Thankfully, I remembered to bring the extension cord (that came with the laptop charger).
Well that’s about it, I have another short conference next week and will probably try again to bring the iPad but that pesky monthly newsletter is due out again…
I am going to a big conference next week, 2 full days out of the office. In times of yore, I would haul my trusty Macbook along and lugging it with me on both days as I move from pavilion to briefing hall, from lunch back to pavilion and from beer hall to bed.
A couple of months ago, I tried using an iPad for a different conference. I purchased an Apple Bluetooth (BT) keyboard and carried it with the iPad for most of the show. With the BT keypad, power input was just as fast as on the laptop and even faster as I didn’t need to boot anything up.
The other nice thing about the BT keyboard with the iPad is you have fine cursor controls (arrow keys) which can be used to position input pointer. I did find having to take my hand off the keyboard and touch the screen for some clicking action disconcerting and there were some iPad applications that didn’t handle the arrow keys appropriately but other than that, it worked great for power input, answering emails, and web searches.
The internal, soft iPad keyboard worked ok but wasn’t nearly as fast and didn’t support Dvorak. Also the soft keyboard in portrait mode only provides 6 lines of pages text which makes power input with feedback more difficult. In any case, I would use it to rip off quick emails, tweets, and other short stuff which worked well enough. I still took notes on paper (probably to old now to take notes on the iPad/laptop). Having the keyboard available with a moments delay, made it easy to decide to take it out to use it when I had the time or leave it in the backpack when I didn’t.
Another positive note was that the iPad took up very little desk space. Most briefing halls nowadays have these smallish retractable desk tops that can barely hold a legal pad let alone a laptop. The iPad fit these postage stamp desktops just fine.
Not sure how to quantify the weight advantage of the iPad+BT Keyboard vs. Macbook without weighing them but it is significant. Given all the junk I carry along with the laptop vs. the iPad+BT keyboard, the iPad/BT keyboard wins hands down. It’s almost like I am not carrying a computer at all.
Problems with using the iPad
There are a couple of web applications (e.g., Wordress visual editor) that seem dependent on flash to work properly, which made using the iPad to create blog posts problematic. Also, scrolling in WordPress post editor seems to be a flash application as well which made dealing with any long post edits problematic at best. Wordpress has an iPhone/iPad application which is just as good as the non-visual editor in web-based WordPress which comes in handy at these times.
Now in all honesty, I haven’t tried these in a while and these may not be flash issues as much as iPad issues. Nonetheless, I will guarantee that you will run into some websites that you use in your daily activities that use flash and won’t work. With the iPad you just will need to forego these websites and find alternatives.
In the office I am a heavy TweetDeck user. For some reason this application doesn’t work that well for the iPad. I have the latest version and all but find using Twitterific or the official Twitter App a better solution on the iPad.
I purchased the WiFi version of the iPad and iPad’s do not come with Ethernet plug-ins. Now most conference centers these days have WiFi, but it may not always work that well. Also some hotels only have WiFi in certain locations and not in the hotel rooms. All this makes having internet access somewhat sporadic. But you can always buy the 3G version if you want to and I always have my iphone for internet access in a pinch (assuming ATT has adequate conference center/hotel coverage).
I was told that the iPad power converter and connection would also charge up my 3G iPhone but this turned out not to work. Luckily, I brought along the power converter for the 3G iPhone by mistake and the cable connection between the power converter and iPad worked just fine for the iPhone. Also the cable from the power adaptor to iPad is somewhat short, so bring the extension cord in order to be able to work with the iPad while its charging.
I ended up purchasing the Apple case for the iPad. I wanted to be able to have it upright portrait or landscape while I was typing on the keyboard, have it slant upward while using the soft keypad and otherwise lie flat. The Apple iPad case does all this without problem.
Microsoft Office documents
Word documents get converted into Pages documents pretty easily but you lose all change tracking, some of the formatting, and other esoteric stuff. It’s probably ok for internal documents but I find putting together a final document using Pages still a problem. But I must say I am a novice here. Also converting Pages documents back into Word seems easy enough.
I have spent even less time with Numbers and Keynote but they seem adequate for minor stuff and if I used them more probably ok for much more sophisticated work. There are other applications that seem to provide better iPhone support for Microsoft Office editing but I have yet to try them on either the iPad or iPhone. Also, beware that converting Numbers documents to Excel and Keynote to PowerPoint require Mac desktop versions of these programs.
Document availability is somewhat problematic. I met one person who emailed work documents to themselves to solve this problem. Email works ok as long as they don’t scroll out of iPad (iPad keeps the latest 200 emails max for any account which includes spam). For this purpose, I used a not-so-well-known email address and emailed my current work documents to that account. iTunes supports a way to copy files to and from the Mac or iPad which seems painless enough but the email interface worked just as well for me and I didn’t have to synch up to have the files transferred.
Beware of changing headers and footers in Pages and trying to alter them in Word once you get it back to the office. It never worked for me. I had to copy the text of the document to another fresh Word file and work the header/footers in that.
Mac based passwords, logins, and security characteristics are a bit difficult and time-consumming to transfer to the iPad. You can manually load them in for any websites and applications you need but there is no way to transfer a whole keychain from Mac to iPad. As such, if you neglect to transfer security credentials for an important website to iPad your out of luck. Now there are some apps that profess to being able to transfer and maintain keychains on the iPhone or the iPad but I haven’t tried them yet.
Other iPad security aspects are even more problematic. The iPad can be setup to require entry of a 4 numeric character string to access it. Another setting will erase the contents of the iPad after 10 failed logins attempts. And MobileMe probably supports some way to erase an iPad that’s out of your hands (it does this for iPhones so I would think the same service would be available for the iPad but I haven’t looked into it).
But despite all that, I don’t feel the iPad is as secure as the Macbook. For one thing, I encrypt the data on the Macbook and the system password can be alphanumeric and considerably longer than 4 characters. In any case the harddrive can be removed from the Macbook but without the passkey, the data on the drive would be useless. In contrast the SSD-Flash memory on the iPad could be pulled out and analyzed without any trouble whatsoever and with proper understanding of IOS storage formatting be read in the clear.
Also the fact that its smaller and lighter it could easily be forgotten and left behind making it more lose-able. And it’s certainly more prone to being stolen because it’s smaller and lighter.
At this point I will probably use the iPad for the upcoming VMworld conference just to see if it works as well the 2nd time as it did the first. It’s only two full days, what can go wrong?