thinking sysadmin

• Your Usable Capacity May Vary – Chuck conducts a thought deployment comparing EMC, HP and NetApp usable space for a 120 disk Exchange deployment. And while he glosses over a couple perhaps non-minor issues (RAID-5 vs RAID-DP and whether EMC’s snapshots are adequately performant), he does hit one of NetApp’s weak spots dead on: Usable capacity, particularly on LUNs if you follow the 100% space reservation recommendation. (Being a NetApp admin these days, I can’t really comment on what he writes about HP – it’s been a long time since I’ve touched that StorageWorks stuff – and I can only repeat what I’ve heard others say about EMC.) More Chuck on this here.
• How to License Windows VMs in a Non Microsoft Virtual Environment: Why Windows Server 2008 Datacenter Edition may be the best choice. (Seen at blog.scottlowe.org.)
• Welcome – My friend, NetApp’s Vaughan Stewart: Chad Sakac highlights some flaws in NetApp’s TR-3697 (“Performance Report: Multiprotocol Performance Test of VMware® ESX 3.5 on NetApp Storage Systems”):
  

  What’s the scoop with:

  * 4K/8K IO size only
  * 2Gbps FC
  * You guys have “throughput/IOPs” shown only in relative, not in absolute.
  * 84 144GB drives with 16 VMs driving the IOMeter workloads with * 10GB of data each on them = 1.3% utilization (rounding up!).

• Performance Report: Multiprotocol Performance Test of VMware® ESX 3.5 on NetApp Storage Systems: A complementary whitepaper to VMware’s own work comparing Fibre Channel, iSCSI and NFS as storage protocols for VMware ESX. (Seen at blog.scottlowe.org.)

On the ESX console, do the following:

• Read the documentation for each patch.
• Group patches that can be installed together into a directory, possibly an NFS mount available on all your ESX hosts.
• Cd into the patch directory and untar the patches:

  for i in `ls *.tgz`; do
tar -xvzf $i
done

• Install the patches:

  for i in `ls`; do
if [ -d $i ]; then
cd $i
esxupdate --noreboot update
cd ..
fi
done

• Reboot.

• File Level Recovery from within a VMDK backup – Nick Triantos of NetApp covers file-level recovery from VMware (Windows) VMDK files again, in more depth than he has before. Nick notes that it can be a “a point-and-click process.”

• VMware to release ESX 3i for free next week – Yeah, the title pretty much says it all; I guess that’s one way to compete with the price of Hyper-V. Now what were those 3i vs 3.5 limitations?

• VM HA – service console networking, isolation behavior – and other “under the covers stuff” – An overview of how VMware ESX’s High Availability works under the hood – making it much more apparent to me how important file locking is to HA’s functioning. (I’d love to see an overview of how file locking does – or doesn’t – differ on VMFS versus NFS datastores.)
• Why Upgrade? – DanT on what’s new in Sun Grid Engine 6.0 through 6.2.
• Part II: Since NFSv4 is Stateful It Must Be Less Robust, Right? – “Just because CIFS is old and busted, that doesn’t mean NFSv4 is.” Just kidding, that’s not an actual quote. But I think it’s a reasonable summary of the piece.
• HP – Performance-Optimized Data Center – Yet another vendor produces a data center-in-a-box product – which isn’t to say that there isn’t good technology inside of HP’s product. I wonder if container data centers will come down-market to the point where they become a reasonable alternative for new office building construction instead of building a conventional server room. (Seen at Data Center Knowledge.)
• Understanding NIC Utilization in VMware ESX – Scott Lowe comes through again with another practical piece on networking and VMware ESX.

• Prediction: Citrix will drop the open source Xen hypervisor for Hyper-V. The rest of the open source world drops Xen for KVM. – Lengthy speculation about the future of Xen now that Hyper-V is out. If this turns out to be correct, I think it leaves Sun in a particularly awkward spot, given that the work they’ve done on integrating Xen with Solaris. (Seen at virtualization.info and vinternals.)

Am I the only one that hates VMware’s patch download site and its corresponding applet? (Maybe – I couldn’t find anyone complaining about it looking quickly on VMware’s message boards, which I found most odd.) I’ve never been able to get it to launch under Firefox, only under IE (even on the same machine with the same JVM). And when it does launch, it is slow as molasses.
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• Blocks & Files: Now HP contributes HPC file system to open source – “HP has contributed its Tru64 UNIX Advanced File System (AdvFS) source code to the open source community, meaning Linux.” It’s been a long time since I’ve used AdvFS (the last time I used Tru64 was in 2003 or so), but it seems to me that this would maybe have been a lot more exciting if it had happened in 2000 or so. They do have a site up on SourceForge with source code already available for download, but I have to wonder how much interest this is going to attract with all the other file systems already out there.
• VMware VROOM!: Scaling real-life Web server workloads – “While the performance of each single-VCPU virtual machine is slightly lower than that of a one-CPU native machine (because of virtualization overhead), the cumulative performance of the multiple virtual machines well exceeds the performance of a large SMP native machine (because serialization penalties are reduced).” In other words, if you know that you have a scale out (instead of scale up) application, you can scale out by scaling up your virtualization server.

• Red Hat adopts KVM: what happens to Xen now? – I work in a VMware ESX shop right now (other than all those Solaris Zones and FreeBSD Jails and OpenVZ VEs, that is) – no Xen or KVM. However, given the serious pain in the butt that timekeeping is in Linux guests on ESX, I’ve been sorely tempted to look at running Xen for some Linux virtuals under CentOS 5, in the hopes that this isn’t a problem there. Guess I’ll hold off on that now. (Yeah, I’ve read all the docs, and Linux time sync generally sorta kinda usually works until it doesn’t – it just shouldn’t be that much of a flail.)
• 10 Gigabit Ethernet and VMware – A Match Made in Heaven – Lengthy and interesting article on 10GbE, VMware, consolidation and datacenter Ethernet – dismissive of Infiniband’s chances of becoming the One True Network Fabric.
• Blocks and Files: Between a server or storage array place – More commentary on Chuck’s commentary on HP’s flash announcement. Quote: “Another aspect of this is that a flash SSD cache for a servers needs to plug in to the server’s bus and the supplier doesn’t have to worry about getting a Fibre Channel interface onto flash SSDs which is needed to plug them into existing Fibre Channel slots in a storage array. STEC has an effective monopoly on this (with EMC having its own mini-monopoly because of its exclusivity deal with STEC which ends in a few months) until Emulex’ SSD-tweaked SATA-to-FC bridge chip becomes available at the end of the year. ” Which is probably why NetApp recently announced this instead of flash drives.