Pointer of RDM / vmfs block size?

Similar Questions

• SAN LUNS vs. VMFS Block Size block size

  Hi all

  I searched a bit and you read some documents on VMFS block sizes and alignment. However, I'm still a little confused. I think I get the concept of aligning vmfs partitions and how the block size affects max vmdk/size of the file on a partition. When creating new virtual disks and LUNS on my SAN, however, I can choose the sizes of different block there, as well.

  Choose size of block even when you create a SAN LUNS as VMFS partition that will reside on this subject? There is also 'the band height' and I wonder how it might affect things. The default value is 64 k, which I was using.

  Thank you very much

  Take a look at: disk partition alignment

  Block is not to same size, cause VMFS use big block (not available at the level of storage).

  André

• VMFS block sizes - that affect files in the disks?

  Hi all

  I know that if we choose a larger block size, we can have a greater total disk (up to 2 TB I think). I also know that if I choose a larger block size, say 8 mb, so that even small files on my vmfs will lead up to 8 MB of disk space. My question is what about small files in vm disks as a windows ntfs running vm. Files on this comments will take the size of large blocks of 8 MB regarless of their size?

  8 mb, so let's say even small files on my vmfs will lead up to 8 MB of disk space

  No, it is a layer of void which takes into account more small files, LESS of pre determined threshold (I don't remember exactly what it is) are not part of this minimum block size.  For small files are 1/64 of the block size.  With the size of block 8 Meg they are 1/256 of the size of the block size.

  So I had the same problem to investigate files newspapers and others, and the VMFS takes into account so you don't waste space.

• VMFS block size during installation?

  I installed ESXi 3.5 u4 on a server with a 900 GB RAID array. The problem is that the ESXi install automaticaly consumes all of the disk with a data store VMFS with a block size of 1 MB. This prevent me to create virtual discs to 256 GB on the data store. I need to create a virtual big 600 GB disk but cannot. How to work around this limitation?

  Is there a way to change the size of the block to 4 MB during installation? Or is there a way to limit the installation to the use of only a 20 GB volume, leaving the remaining space for a new 600 MB VMFS volume that I create through the console without problem? Y at - it a boot disk utility that I can use to create the small partition setup ESXi will recognize?

  Assuming that you have not added any virtual computer, you can remove the data store and recreate it using your chosen block size.

• storage on the block sizes and vmfs5 issue

  We just bought a new table with a feature called FlashDisk SSD read caching.

  the implementation of suppliers of this technology is the following: it basically puts cached applications frequently read blocks that are 16 KB or smaller in dedicated controller SSD, up to 1.6 TB per controller.

  We worry about what we paid extra money for SSD read cache and I was wondering if it will ever come into play because VMFS5 file system uses the block size of 1 MB.

  WE have Oracle DB currently set to use 8 k block size.  Now if VMFS collects the Oracle 8 KB please and puts them in blocks of 1 MB, then Im I right to believe that the read SSD cache pool will never be used?  y at - it a way to allow the Oracle 8 KB blocks to get to take advantage of the SSD cache using file vmfs5 reading system?  or is the necessary RDM here?

  Thank you!

  Now if VMFS collects the Oracle 8 KB please and puts them in blocks of 1 MB, then Im I right to believe that the read SSD cache pool will never be used?

  No, your assumption is incorrect. The size of the block VMFS is only for the sake of allocation/address of the files on the will. The size of the block VMFS has no influence IO issued by the virtual machines.

  This means that a request for/o 8 k of a VM will arrive as an application of e/s of the same 8 KB on the backend storage.

  The VMFS block size is completely independent and transparent to both, the back-end storage device and the behavior of the computers own IO virtual.

• Question of size for VMFS block

  I created a 600 GB LUN. Then I go to the ESX host that contains the data - tab Configuration - Storage store - select the data store.

  Why does say that my 600GB LUN is a block size of 8? When I create a 600 GB LUN, should not be a block size of 4?

  He said that my VMFS filesystem is 3.46.

  I'm under vCenter 5.0 with ESXi 4.1

  Thank you

  I created the data store via my interface EMC e 3100

  I ' don't know this interface, but this could create the data store with a block size of 8MB. In any case, there is basically nothing wrong with the block size of 8MB. You don't have a degradation in performance compared to a different block size.

  André

• 1.8 to VMFS watch block size of 1 MB - WTF?

  We have a box 4.0 on which we have created multiple VMFS, each about 1.8 TB volumes.

  All three volumes appear and we have been using them, but today we came to increase the size of a VMDK and found that he maxed out at 256 GB.

  By looking at the properties of VMFS volume, all three show that 1.8 to, or one of them (one is this VMDK) shows a block size of 1 MB.

  By definition, if I understand correctly, you cannot have a 1.8 to VMFS with block size of 1 MB, so what is the best way to combat this?

  The server is a stand-alone, so it is not shared storage, nor is the server connected to a vCenter server.

  Thanks in advance.

  Block size does not affect the size of VMFS, it only affects the maximum size of the single VMDK file. So, it is perfectly valid to have datastore VMFS 1.8 to with 1 MB block.

  You must evacuate all virtual machines that store of data and reformat the drive with the largest block, I'm sorry, but it's your only option.

  Tomi

  http://v-reality.info

• A procedure to follow to change the block of VMFS Volume size?

  We use a VMFS volume with size of 1 MB blocks.  As the virtual HD size must be greater than 256 GB, to change the size of the block to 2 MB.

  We would like to confirm that the following is correct:

  (1) to migrate all VM this VMFS volume

  (2) delete this VMFS of ESX Cluster

  Add 3) as storage again

  4) format with the 2 MB block size

  Is it Miss?

  Thank you

  There is not another possible procedure

  But as already shown reflect the selection of block size.

  ---

  MCSA, MCTS, VCP, VMware vExpert 2009

  http://blog.vadmin.ru

• Block size of a VMFS data store limitations

  I installed my ESXi 5 server with the default block size

  For the moment, I'm trying to convert the Windows Server 2008 and I have the alert message is: "*.vmdk file is larger than the maximum size.
  supported by the data store.

  It is possible to change the size of the block after the installation of ESXI5?

  Please can you help me because I have converter many server and it is not possible to re install my ESXi server.

  Help, please.

  The screenshot I understand you try to make a volume based cloning and you have deselected (i) and selected a share resource (FAT).

  It is possible to deselect the share (in BOLD) resource and give it a try

  Is - this possibe on a disk based cloning an audit?

  Just to be safe, you have enough space on your data store to perform this conversion, and what version of Converter do you use?

• How to shrink thin comments on VMFS5? or change the block size?

  Hi all, I'll try to find a way to reduce invited bloating thin-set in service in an environment VMFS5 all.

  We went from 4.1 to 5.1 and then also vmotioned storage all our newly created vm VMFS5 volumes before you delete the old VMFS3 volumes.  During this operation, everyone has forgotten that one of our volumes has been intentionally assigned to a block size of differnet than all the others for the purpose of narrowing of the guests who had swelled upward for some reason any.  Now, we have no way to create something other than a volume of 1 MB block size which prevents us from doing the cleaning routine.  Is there an alternative way to shrink a guest who does not put offline?

  For those who do not know the procedure that I describe, here's how it works:

  You have a 100 GB comments that has only 10 GB of actual data in it, but because of something after bad temporary files, cleaning up old data, etc., that 100 GB had been used at a point of real files but is now only 10 GB in use. You want to recover which is now 90 concerts waste of space because your thin provisioned VMDK is sitting there at 100 GB in size.  With VMFS3, you could create a volume with a block size that was different from that of the volume on which the guest is currently living.   In our environment were all our 1 MB LUN but one that we kept to 2 MB just for that purpose.   When we were getting a little low on space and found guests such as the one in question, we would run a simple command to write zeros to the entire free space:

  Cat/dev/zero > bigfile; RM f bigfile

  Then all you have to do is storage vMotion the guest at the volume of 2 MB and return to its normal domestic and suddenly the VMDK's 100 GB up to 10 GB, all with no impact on the guest.  Without support for the creation of a file system with a different block size in VMFS5, now I'm not aware of a way to reclaim this space in a way that does not require an interruption of the guest.

  You can select the VMFS version when you create a new data store. With selected VMFS3, you will be able to specify the desired size of the block.

  André

• How to increase the block size?

  Community VMWare greetings,

  Recently, I installed ESXi 4.0 on Dell PowerEdge T300 server - within this server, I have two raid arrays - one for the operating system (which is an array of 2 GB) and one for the data (which are a picture of 741 GB).  ESXi installed without problem - when I have connected to the server using vSphere machine already had two warehouses of data (datastore1 and datastore2).

  Unfortunately, datastore1 (741GB Bay) has a block size of 1 MB.  I did some research and found that a block size of 1 MB only supports a 256 GB drive size.  I have a server of 300 GB I need to virtualize, so I would like to increase the size of this block to 2 MB or 4 MB.  How can I do this?

  I'm sorry to say, but you need to remove the data store VMFS move all the data off of him and then recreate the VMFS data with the correct block size store.

  If you find this or any other answer useful please consider awarding points marking the answer correct or useful

• Dealing with the Local Storage block size (vSphere 4)

  I have a pretty basic question / easy I think I know the answer want to but to double check.  I spaced that vSphere 4.0 uses a default size of 1 MB, which began to cause problems with our backup software try to attach block vmdk is greater than 256 GB in size.  I want to continue to use local storage for our assistants of esXpress but to do this I need to have a larger block size to the local vmfs volume...  Question is can I safely delete the local storage (if nothing is done off of it) and add it and increase the block size or is there a way of installing to set greater than 1 MB block size?

  Easy points.  Thank you guys.

  • Kyle

  Remember, by default your COS is installed on local storage, so do not remove.

  I think this article gives you the best solution

  http://KB.VMware.com/kb/1012683

• Storage vmotion, between data warehouses when the block size is different

  Hi all

  I would like to know, is it possible to do a vmotion of storage between two data warehouses, when they have different block sizes. The case is as a former vmfs data store 3 which has been upgraded direct to vmfs5 there, but since it has been updated it maintains its own block size. While the newly created vmfs datastore 5 a block size of 1 MB.

  Thus, storage Vmotion will work in this case? It will fail OR will be with degraded performance?

  Finally, storage vmotion is possible even if you do not have a cluster DRS for storage?

  Thank you

  Yes you can!

  Check some info on the effects of block size: http://www.yellow-bricks.com/2011/02/18/blocksize-impact/

• Block size of data store

  Hello

  First time post and quite new to the product.

  Does anyone know why the option of block size to store data in the client default vSphere to 1 MB in size?  I see in the tutorials and blogs, there are options in the updated section in shape for up to 8 MB?

  Thanks for your help.

  Hello, welcome to the communities.

  Here is some information on the sizes of block VMFS and their constraints;

  VMware KB: Block the size of a VMFS data store limitations

  VMware KB: Frequently asked Questions on VMware vSphere 5.x for VMFS-5

  Don't forget, when you upgrade from an earlier version of VMFS, the block size is preserved. Newly put VMFS-5 data warehouses have a unified 1 MB block size.

  See you soon,.

  Jon

• Change the block size of 1 MB (4 MB or 8 MB)

  Hi all

  I'm in a delemia.  I have an ESXi installed 4.1 vSphere but I used the block of 1 MB by default when the size isstalling ESXi.  I have turned Virtual Machines for some time on this topic and may not all simply re - install the ESXi again.  I am currently in need greater than 256 GB drives in my virtual machines.

  What I read for possible patches to change the 1 MB to 4 MB or 8 MB data store to support more than 256 GB drives is to add to the new temporary HDD on the server and create a new store of data on it with the block size of 4 or 8 MB and then migrate the virtual machines to the new larger block size datastore.  Then re - initialize the original 1 MB data store such as a 4 or 8 MB and migrate to the original data store.

  Two questions about this:

  (1) is my eventual detailed correction?  In other words, I add another, say, 8 MB block size datastore, although I have implemented the ESXi server as a 1 MB? Or will it just automatically initiaize the new temporary data store like 1 MB anything?

  (2) If this correction is possible, the passage of the VMS in a data store from 1 MB to 8 MB data store will have reprecussions?  In other words, move a Virtual Machine with the 1 MB block size to a data store with 8 MB is a problem with this virtual machine?

  Any suggestion would be great.

  Thanks in advance.

  -Dan

  Welcome to the community,

  You can format each data store (which is just a partition with a type of VMFS partition) with a different block size and move the VM back if you wish. However, if your hardware supports ESXi 5.x, this can be an easier way to solve the dilemma, because after the upgrade to ESXi 5.x, you can also upgrade the VMFS3 data store to VMFS5 which supports the file (virtual disk) sizes of up to ~ 2 TB with a unified 1 MB block size.

  André