VMware Cloud Community
ChrisOng
Contributor
Contributor
Jump to solution

Vmware Block Size set to 2 MB

Hi,

I have configure the SAN to set to 2 MB which can be used up to 512 GB per vmdk.

Does this 2 MB means that the data will write to the SAN in a block of 2 MB. For example, if a file is copy say only 100k, thus it will allocate 2 MB consume on the SAN Storage?

Thanks

Reply
0 Kudos
1 Solution

Accepted Solutions
AntonVZhbankov
Immortal
Immortal
Jump to solution

Samir, you should add two more rows here: I/O speed and Security.

Thick

ZeroedThick

Thin

EagerZeroed Thick

I/O speed

Max all the time

Reduced at beginning due to zeroing blocks on first access

Reduced slightly more than ZeroedThick due to allocating and zeroing blocks on first access

Same as Thick

Security

Insecure - VM can read what was on partition before VM deployment

Secure

Secure

Secure


---

MCSA, MCTS, VCP, VMware vExpert '2009

http://blog.vadmin.ru

EMCCAe, HPE ASE, MCITP: SA+VA, VCP 3/4/5, VMware vExpert XO (14 stars)
VMUG Russia Leader
http://t.me/beerpanda

View solution in original post

Reply
0 Kudos
3 Replies
AndreTheGiant
Immortal
Immortal
Jump to solution

You work on a vmdk file, not on single files.

If you use a thick vmdk disk, then the file is already allocated...

Andre

Andrew | http://about.me/amauro | http://vinfrastructure.it/ | @Andrea_Mauro
Reply
0 Kudos
kooltechies
Expert
Expert
Jump to solution

Thick

ZeroedThick

Thin

EagerZeroed Thick

Creation Time

Fast

Same as Thick

Fastest

Extremely slow, and linearly proportional to size of disk

Block Allocation

Fully preallocated

Same as Thick

• Allocated, on demand, on first write to the block

• Zero size on creation

Same as Thick

Virtual Disk Layout

Due to preallocation, it has a higher chance of using contiguous file blocks.

Same as Thick

Layout varies according to dynamic state of the volume at the time of on-demand block allocation.

Same as Thick

Zeroing of Allocated File Blocks

File blocks are not zeroed out.

File blocks are zeroed, on demand, upon first write to virtual disk.

File blocks are zeroed out upon block allocation.

File blocks are zeroed out upon creation of the virtual disk (blocks are allocated and zeroed).

Some more information on various disk file formats.

Thanks,

Samir

P.S : If you think that the answer is helpful please consider rewarding points.

Blog : http://thinkingloudoncloud.com || Twitter : @kooltechies || P.S : If you think that the answer is correct/helpful please consider rewarding points.
Reply
0 Kudos
AntonVZhbankov
Immortal
Immortal
Jump to solution

Samir, you should add two more rows here: I/O speed and Security.

Thick

ZeroedThick

Thin

EagerZeroed Thick

I/O speed

Max all the time

Reduced at beginning due to zeroing blocks on first access

Reduced slightly more than ZeroedThick due to allocating and zeroing blocks on first access

Same as Thick

Security

Insecure - VM can read what was on partition before VM deployment

Secure

Secure

Secure


---

MCSA, MCTS, VCP, VMware vExpert '2009

http://blog.vadmin.ru

EMCCAe, HPE ASE, MCITP: SA+VA, VCP 3/4/5, VMware vExpert XO (14 stars)
VMUG Russia Leader
http://t.me/beerpanda
Reply
0 Kudos