thinking sysadmin

• HP servers to get flash memory I/O boost – It looks like SSDs will become a common option on server hardware; the real issue will be how to adapt your operating system/file system/application to use them optimally.
• BlueArc’s Titanic benchmark holed – A storage vendor using a non-real-world configuration to optimize benchmark results? Really? Say it ain’t so!

• Cloud Computing: Is the Cloud There Yet? – A Brief History: A mostly negative look at the prospects for cloud computing. Although the arguments it makes are fairly reasonable, the article appears to presume that cloud computing is an all-or-nothing proposal, not a tool for only some tasks. Also odd – “Many routine tasks which are not processor intensive and time critical are the most likely candidates to be migrated to cloud computing” seems wrong (think Sun’s network.com, or how SmugMug uses EC2). Further, the article seems to ignore that big pharma and financial institutions are the largest users of AWS. Still, all in all, a perspective worth considering. (Originally seen at InsideHPC.com.)
• What he said! – scalability.org: Joe Landman on “IT clusters. They are not HPC clusters by any stretch of the imagination. They don’t really work well. Some things sorta-kinda work. Lots of things don’t or cannot. You have some interesting failure modes.” I’ve seen exactly what he’s talking about from the biosciences arm of a large hardware/services company, where they sold something that was high margin, poorly configured, had a lousy interconnect, and, yes, was running RHEL. The article’s use of “IT” as a disparaging term was also interesting. (Also seen at InsideHPC.)
• EMC flashing CLARiiON? – Rumor that flash from EMC is slowly starting to march down-market.

There’s been a lot of noise from the storage industry about flash recently – in particular, noise from EMC and Sun, both of whom recently announced storage products using flash, EMC in January and Sun earlier this month. Below are my thoughts on what EMC and Sun are doing, as well as what NetApp might do. Since I see a fair amount of visitors from all three companies here, if I’ve got something about your employer wrong, please correct me in the comments.
Read the rest of this entry »

• Adam Leventhal’s Weblog: Flash, Hybrid Pools, and Future Storage – Excerpts from a forthcoming ACM article on hybrid (flash-disk) storage pools, including: “Flash should be viewed not as a replacement for existing storage, but rather as a means to enhance it. [...] By combining the use of flash as an intent-log to reduce write latency with flash as a cache to reduce read latency, we can create a system that performs far better and consumes less power than other system of similar cost.” Which perhaps could be thought of as a dig at EMC’s flash implementation, although I doubt that’s how the author intended it. (Seen at c0t0d0s0.)

• Jonathan’s Blog: Anything But a Flash in the Pan – Jonathan Schwartz on Sun’s soon-to-be-released (late this year) flash drives. Quote: “ZFS will transparently incorporate Flash into the storage hierarchy of a running system, using the microprocessor cache for the most performance sensitive tasks, DRAM for the next, then Flash, then disk (then ultimately tape).” Speaking of tiered storage, I wonder how flash drives would work within a SAM-QFS implementation – and if SAM-QFS is destined to wither in the shadow of ZFS: Sure it’s open source now, but where is it going these days?

• Eucalyptus – “EUCALYPTUS – Elastic Utility Computing Architecture for Linking Your Programs To Useful Systems – is an open-source software infrastructure for implementing “cloud computing” on clusters. The current interface to EUCALYPTUS is compatible with Amazon’s EC2 interface, but the infrastructure is designed to support multiple client-side interfaces.” If VMware is perhaps working on responding to EC2, this could be thought of as EC2′s response to VMware ESX, in a way – although it’s coming from UCSB, not Amazon. Notable: This is a product that layers on top of a Rocks cluster installation. (Seen at High Scalability.)

• Performance Isolation of a Misbehaving Virtual Machine with Xen, VMware and Solaris Containers – A paper comparing the ability of VMware (Workstation), Xen and Solaris Containers to isolate virtual machines from each other with regards to performance. Quick summary: VMware and Xen go one-two in protecting one virtual machine from another, and Solaris Zones lag far behind, a definite trade-off to consider if you’re inclined to use zones for their higher density. I would expect similar results to what was reported with Solaris if the authors had also looked at OpenVZ and FreeBSD Jails – in fact, (anecdotally) I’ve seen generally the same behavior with OpenVZ and Jails, although OpenVZ does give you a lot of knobs to adjust (if performance isolation is a concern for you with OpenVZ, you may want to look at all the options it gives you before making decisions about its suitability). It would have been nice to see more details about the Solaris configuration used in the paper, and to have had the work repeated with a recent OpenSolaris build – substantial work appears to be being done in this area (for example, Improved Resource Management and Zones Integration). Seen at blog.scottlowe.org.

• Evolution of the Virtual Datacenter – You didn’t think that VMware was going to stand idly by and let EC2 and Xen become the default cloud virtual platform, did you? Well, they’re implying they’re not going to let that happen with this slide, at least. Seen at virtualization.info.

• Chuck’s Blog: Vendor Differentiation Through Thought Leadership – (Yeah, that title made me gag, too.) Excerpt: “Sun came out loud and strong recently with characteristic unbridled enthusiasm. But, in classic Sun fashion, they missed the point entirely. It’s not just the flash drives (they’re just components, right?) it’s what you can do with them for customers. Seems that their target use case is ZFS running on a storage-oriented server. Not the most compelling use case, IMHO.” Maybe it’s just cynical old me, but I read that as “Sun has some pretty good technology with their server hardware and ZFS, Lustre and SAM-QFS; they might be able to put something together that could really hurt our margins, not just NetApp’s. Flash drives might help them do it. Uh-oh. Maybe we better hurry up and ship Maui.” The Sun/Intel PDF that Chuck links to is actually pretty interesting, although it would have been good to see some more numbers.

• Ubuntu Netbook Remix – “A ‘remix’ of the standard Ubuntu Desktop 8.04 release to enable it to work better on devices with small screens, such as Netbooks (sub-notebooks).” I’ve been meaning to replace Xandros on my Eee with Ubuntu – it’ll be nice to have this on top of Hardy Heron. (Seen at Ars Technica, whose post has more info and some nice screenshots.)
• Internet Traffic Growth Doesn’t Matter – A look at Internet bandwidth consumption that sounds quite level-headed to me. A few great quotes, some of them excerpted from a presentation by Andrew Odlyzko: “Internet traffic growth rates are slowing. Hype is accelerating.” “Telecom is the only industry that worries about it’s [sic] customers using too much product.” “Volume is not value. SMS messages consume almost no bandwidth but bill out at $1000/Mb.” “Traffic growth simply doesn’t matter. Period. What matters is revenue.” And best of all: “Most people think they are special but in realty [sic] just want to watch ‘American Idol’.” (Seen at Data Center Knowledge.)