Like most people, and with just over a week to go before the conference, I’m putting the finishing touchs on my various presentations. First up for me, on Monday afternoon, is my tutorial: Scale Up, Scale Out, and High Availability: Solutions and Combinations. What will be doing? Very simply: Looking at every potential solution for maximum scalability and availability for your database environment. If you are attending, be prepared to:
- Expand your mind as we think about scaling up.
- Expand your horizons as we think about scaling out.
- Divide and conquer, as we think about high-availability.
We’re not not hands on in this session – but I will expect you to be brains on!
Using a static disk, or even just multiple disks, within Parallels can make a big difference to performance. This is particularly true with Windows virtual machines within OS X; I’ve managed to change the boot time from about 30 seconds to under 20 just by changing to a static disk for VM. The default disk in Parallels is an expanding type – this saves disk space, because Parallels automatically adds to the size of the disk as you need it, but it also means that Parallels has to manage the allocated disk space, adding to the file used. Not only does the management imply a small overhead, there is a much larger chance of the file being fragmented. A more annoying effect is that the constant use of the expanding disk with virtual memory under Windows, means that size of the disk may increase just because you opened a large application once. You can get round this by creating a statically-sized disk, and then setting the virtual memory within your virtual host, to use this statically sized disk. To do this:
- Shutdown your virtual machine – you cannot do this with a machine in the paused stated, because you are effectively adding new hardware to the machine.
- Click Edit to edit the configuration for the virtual machine.
- Click Add, and select a new hard disk
- Unclick the Expanding checkbox and set the size; probably 1-2GB is fine, but keep in mind you will lose this amount of disk space permanently, even if your VM doesn’t use it all.
- Save your configuration.
- Start up your VM and configure the new drive.
- Log in as a user with Administrator privileges.
- Right click on My Computerand choose Manage.
- Choose Local Disk Management.
- Create a new partition/volume.
- Once the new disk is ready to use, right click on My Computer again, and choose Properties.
- Click the Advanced tab.
- Click Settings under Performance.
- Click the Advanced tab.
- Click Change under Virtual Memory.
- Reconfigure the VM settings, creating the new settings for the new drive (I recommend a lower value of 50MB and an upper value 2-10MB below the maximum size of the disk. Windows will use the minimum and dynamically increase it’s usage up until the maximum.
- Remove the VM configuration for the original system/expanding disk.
You should be all set.It’s probably a good idea to run the Parallels Compressor and reduce the size of your disk now that you are no longer using the disk for virtual memory. For Linux, Solaris and other Unix variants you might want to run, the process is of course slightly different. For some environments, there are other benefits, but I’ll cover that in a separate post.
Parallels for Mac has been updated, but its the stuff beyond the highlight elements that I find most interesting.The headline elements are:
- Support for the new Mac Pro (and up to 3.5GB RAM
- Support for Mac OS X 10.5 (Leopard)
- Experimental support for Vista
That’s all great, and I’m just installing Vista beta 2 on the iMac as I type this on the MBP. However, for me the key elements are:
- Solaris guest OS no longer hangs after suspend/resume – this was a really annoying issue that begged me no end. Although my iMac 17″ stays on full time, my MBP is set to sleep after an hour, but leaving it alone while I’m updating Solaris 10 or running tests would mean that I’d have to force a reboot and sometimes start again.
- Solaris doesn’t work with more than one virtual disk fix – this was particularly annoying, as I’ve been playing with ZFS, and having multiple, virtual hard disks to toy with would have been much better than playing with partitions.
So far, the new version seems great. Being able to play with ZFS (even with expanding disks) is fantastic. I’ve been too busy to let the machine sleep and trigger the freezing problem.