Just read an interesting post by Scott link
- More than 53,000 VCP certifications have been issued worldwide across all versions!
- There are more than 15,000 VCP4 holders worldwide!
Pretty impressive since the VCP4 certification is only 6 months old.
New Performance Course
During the weekend I have been reading the complete beta student manual for the performance course. All I can say at this time: Look forward to it! 🙂
PVSCSI – update
Just read on Scott Drummond’s that in the a future release, the PVSCSI adapter will be good for both low-io and high-io virtual machines. Check out Scott’s blog for all the info.
For now use the PVSCSI for virtual disks with more than 2000 iops.
CPU reservations
Update: Maybe I was a little quick. The problem occured because I set the reservation on a powered on virtual machine. So my conclusion is: Don’t set it higher on powered on virtual machines. If you set it on a powered off and try to power it on, admission control would tell you it is not possible.
I was just playing around with CPU reservations in vCenter. I wanted to verify that it actually works. I have been playing around with limits and shares a lot but never really tested cpu reservations.
The server I tested it on is a Intel Xeon E5410 (quad core 2,33ghz). I created 8 virtual machines and started the cpubusy.vbs we use on the vmware courses. At first I started out with no reservations for any of the machines.
Test 1: No reservations (Every VM is equal and results are what I expect)
_________________________________%USED %RDY
38 38 frped-1 4 48.51 48.78 0.01 300.05 52.32 0.00 0.24 0.00 0.00 0.00
39 39 frped-2 4 47.55 47.62 0.06 300.14 53.40 0.00 0.20 0.00 0.00 0.00
40 40 frped-3 4 46.83 46.98 0.00 299.84 54.33 0.00 0.15 0.00 0.00 0.00
41 41 frped-4 4 49.25 49.37 0.01 300.02 51.76 0.00 0.14 0.00 0.00 0.00
42 42 frped-5 4 47.80 47.91 0.01 299.84 53.40 0.00 0.13 0.00 0.00 0.00
43 43 frped-7 4 47.63 47.81 0.00 299.82 53.55 0.00 0.18 0.00 0.00 0.00
44 44 frped-6 4 48.32 48.47 0.01 300.03 52.68 0.00 0.16 0.00 0.00 0.00
45 45 frped-8 4 48.17 48.36 0.01 300.29 52.54 0.00 0.20 0.00 0.00 0.00
Test 2: Reservation 2400 mhz on frped-1 (Nothing happens?)
________________________________%USED %RDY
38 38 frped-1 4 47.81 48.02 0.00 299.75 52.80 0.00 0.17 0.00 0.00 0.00
39 39 frped-2 4 48.41 48.68 0.01 299.29 52.60 0.00 0.20 0.00 0.00 0.00
40 40 frped-3 4 48.00 48.10 0.01 299.25 53.21 0.00 0.13 0.00 0.00 0.00
41 41 frped-4 4 47.58 47.68 0.01 299.48 53.41 0.00 0.14 0.00 0.00 0.00
42 42 frped-5 4 46.91 47.05 0.00 299.23 54.30 0.00 0.14 0.00 0.00 0.00
43 43 frped-7 4 47.93 48.06 0.00 299.64 52.87 0.00 0.14 0.00 0.00 0.00
44 44 frped-6 4 48.35 48.69 0.01 298.62 53.26 0.00 0.33 0.00 0.00 0.00
45 45 frped-8 4 48.06 48.34 0.00 299.61 52.62 0.00 0.18 0.00 0.00 0.00
Test 3: Reservation 2300 mhz on frped-1 (WORKS)
________________________________%USED %RDY
38 38 frped-1 4 97.74 97.70 0.01 298.35 2.90 0.00 0.19 0.00 0.00 0.00
39 39 frped-2 4 39.89 40.07 0.00 298.08 60.78 0.00 0.20 0.00 0.00 0.00
40 40 frped-3 4 41.02 41.17 0.00 297.84 59.95 0.00 0.15 0.00 0.00 0.00
41 41 frped-4 4 39.96 40.11 0.01 297.95 60.90 0.00 0.14 0.00 0.00 0.00
42 42 frped-5 4 42.34 42.44 0.01 298.42 58.12 0.00 0.14 0.00 0.00 0.00
43 43 frped-7 4 42.40 42.56 0.00 298.47 57.95 0.00 0.17 0.00 0.00 0.00
44 44 frped-6 4 39.85 40.20 0.00 297.78 60.99 0.00 0.13 0.00 0.00 0.00
45 45 frped-8 4 41.18 41.18 0.00 297.50 60.29 0.00 0.21 0.00 0.00 0.00
LSI Logic or PVSCSI for your virtual machines?
Just stumbled over an interessting KB at vmware.com
With vShpere a new PVISCSI virtual disk controller has been introduced. The new controller is good for high IO intensive virtual machines. What is new (at least for me) is that it is better to use the LSI Logic controller for low-io workloads.
The KB states you should use the PVISCSI for vm’s with more than 2000 IOPS! That is a lot of IOPS, so just continue on using the LSI for most of your workloads.
- PVSCSI is best for workloads that drive more than 2000 IOPS and 8 outstanding I/Os.
- LSI Logic is best for workloads that drive lower I/O rates and fewer outstanding I/Os.
VMFS 3 versions – maybe you should upgrade your vmfs?
UPDATE: Apparently it does not matter if you upgrade your VMFS or not – Check out the following blog post that corrects me on this subject: http://bit.ly/hv9pKo
Ever since ESX3.0 we have used the VMFS3 filesystem and we are still using it on vShpere. What most people don’t know is that there actually is sub versions of the VMFS.
- ESX 3.0 VMFS 3.21
- ESX 3.5 VMFS 3.31 key new feature: optimistic locking
- ESX 4.0 VMFS 3.33 key new feature: optimistic IO
The good thing about it is that you can use all features on all versions. In ESX4 thin provisioning was introduced but it does need the VMFS to be 3.33. It will still work on 3.21.
The changes in the VMFS is primarily regarding the handling of SCSI reservations. SCSI reservations happens a lot of times. Creation of new vm, growing a snapshot delta file or growing thin provisioned disk etc. (KB1005009)
If you have started out with vShpere all of your VMFS will be 3.33. Then there is really nothing to think about. But if you have been running ESX3 and upgrading your hosts to 3.5 and later 4.0 there is a good chance your VMFS is at 3.21. If that is the case I would recommend you to upgrade your VMFS to the newest version. So how do you upgrade? Either cold migrate or storage vmotion all virtual machines and templates away from a datastore. When the datastore is empty delete it and create it again.
So how do you find out what version your VMFS is running? Simple, you can see this information from the vShpere client. Go to Configuration – Storage and select a datastore. Then look in the datastore details:
Fast Track delivery
I just delivered a Vmware 5 day Fast Track course. The Fast Track course is an intensive course and it ran from 9.00-18.00 monday to friday. It was a great class and we had a lot of good discussions. On the last day one of the students took the VCP exam at 7.00am in the morning. He passed it. Well done!
First post
Blog open 🙂