vmware ESXi slow disk speed

[Dara]

Hi, just tough that i might share some nice info..

I have several vmware ESXi (3.5x and 4.x) servers and alot of FreeBSD VM:s (7.x and 8.0) and have had allot of problems with slow disk speed..

And i just updated some of the ESXi:s with the latest updates from vmware (now version 4.0.0 build 261974) and the disk problem seems to have gone away..

I have search for answers to this for quite a while and was concerned that i would have to change to linux or even worse Windows.. so for me at least this was good news.

/Daniel

 

[vigolcom]

Outdated threads, but could useful for someone!
tips:
1- Using non-growable or preallocated VMDK disks.
2- Remove all snapshots in the guest operating system or store performance-sensitive data on an independent virtual disk
3- Install the host operating system onto a separate hard disk than the virtual machines
4- Store the paging file or swap partition on a different drive than the host operating system.
5- Run disk defragmentation software on the host and in the guest operating system.
6- Implementing partitions inside the guest operating system or host can improve performance by creating fragmentation boundaries and can reduce further fragmentation.
7- Certain RAID configurations can impact read or write performance positively and negatively.
8- Disk encryption can reduce disk performance.
9- Often disk problems such as bad sectors or failing controllers can impact performance because I/O and bad cluster auto-recovery can cause sudden interruptions in I/O operations to the device.
10- In general, hardware RAID and independent disk controllers perform better than software RAID and integrated disk controllers.
11- Adding the following settings to a virtual machine can reduce the I/O load on the hard disk, however these adjustments require additional memory on the host.
Open the .vmx file for the affected virtual machine while it is powered off. Add the following lines to the file using a text editor.
Note: If you are using VMware Server, you may need to restart the VMware Authorization Service (vmware-authd) for changes to take effect.

MemTrimRate = "0"
mainMem.useNamedFile= "FALSE"
sched.mem.pshare.enable = "FALSE"
prefvmx.useRecommendedLockedMemSize = "TRUE"