Disk IO Issue in vmware free esxi server in VM

[PraveenStreebo]

Hi All,

We are facing issue with DIsk IO operation in our VM. We are using free ESXI server 6.5 on our Dell server.

We have created VM with Paravirtualization controller and selected disk type Thick Provision Lazy Zeroed but we have still same issue with disk IO speed.

I have checked with DISK IO Operation with below command on Linux VM.

# dd if=/dev/zero of=/tmp/test7.img bs=16M count=65 oflag=dsync
  65+0 records in
  65+0 records out
  1090519040 bytes (1.1 GB, 1.0 GiB) copied, 70.8026 s, 15.4 MB/s

# dd if=/dev/zero of=/tmp/test2.img bs=1G count=1 oflag=dsync

1+0 records in 1+0 records out 1073741824 bytes (1.1 GB, 1.0 GiB) copied, 56.1572 s, 19.1 MB/s  

Please help me to resolved this issue.

Looking forward for reply on the same.

Thanks

PK

[scott28tt]

What numbers did you expect to be seeing?

Useful CLI tool and reference: ESXTOP - Yellow Bricks | Yellow Bricks

[PraveenStreebo]

Hello Scott,

Thanks for your reply. I am currently able to see 15.4 MB/s for DISK IO speed. I am expecting to IO speed at least 70MB/s. We have RAID 5 configured on Dell server.

[scott28tt]

Use ESXTOP as per the link I posted previously - there are various DISK metrics in that article.

[IRIX201110141]

The "Lazy Zeroed" format have a write penalty for the first write.  Convert to Eager-Zero-Thick and try again.

What type of PERC you have in your Dell Server?

Regards,
Joerg

[PraveenStreebo]

Ho Joerg,

Thanks for your reply. I will try this one for VM.

I just want to confirm that if I create the VM with Eager-Zero-Thick then it will not touch /format any existing other running VMs data right?

Please guide me for the same.

Thanks

PK

[JafarTavana]

you can create vms with different Disk /format and they work properly , just you must keep in mind your overall storage size.