Im only talking about shrinking thinprovisioned disks. If youve thinprovisioned a vmdk under esxi and need to reduce it for whatever reason, the official vmware documentation suggest to migrate the vm to another datastore using vmware converter which is not always practical, thankfully an alternative exists. The ugly truth about thin provisioning and the ntfs silent treatment. How to shrink a vmdk using vmware converter techrepublic. I have a vm assigned about 2tb thin provisioned of disk space and it utilizes just about 300gb. Before we can use vmkfstools to shrink the vmdk file we must zero out any unused space on the thin provisioned disk. Unmap is enabled automatically as in windows server 2012 or above. Windows server thin provisioning features serve as interfaces between. What is the best way to shrink a thin provisioned disk. To shrink a thinprovisioned vmdk the guest filesystem has to be zeroed out. The grain size that you select affects the maximum virtual capacity for the thinprovisioned volume.
I wanted to give myself a head start so i began setting an esxi environment inside vmware. This will discard all unused space instead of defragmenting. Windows does not include these drivers, but they can be installed from the guest. I am doing an educational project where i have to setup 3 or more windows 2008 r2 servers on a machine running esxi. Storage arrays that support native thin provisioning features may include tools that monitor storage utilization and send alerts when volumes reach predefined limits basically monitoring the storage system 247. Possibly the biggest issue that we have with thin provisioning is running out of space on a device that is thin provisioned at the backend. As discussed above, using the asm filter driver with the thin provisioned attribute set to true can reclaim space when the tablespace is dropped. The grain size of 8 kb is the default size for thin provisioned volume copies in data reduction pools. Jun 29, 2009 using the vmtools shrink option in a windows vm with vmware tools running, you can rightclick the vmtools icon and select open vmware tools. While thinly provisioned volumes can grow, they remain extremely difficult to shrink without using the newest operating systems. Sql server virtual machine storage design virtualizing sql. The underlying blocks are allocated asandwhen a write is issued by the host to the disk. Vmware vmdk shrink and storage thin provisioning 101. Thicktothin and thintothick virtual disk provisioning conversion is one of the most common operations performed by the it staff administering a virtual environment.
Reclaim, reclaim state on indicate that storage and aix disk driver supports. Shrinking a thick provisioned disk in vmware esxi 5. How to shrink a vmdk using vmware converter by rick vanover in data center, in virtualization on february 26, 2012, 10. I know i cannot shrink a thin provisioned drive and everything ive read says use the vm converter and it requires a downtime. The command helps thinprovisioned storage arrays to reclaim unused space from the vmfs datastore and thin virtual. A simple way of doing this is by using a free utility called sdelete from sysinternals. Convert a virtual disk from thin to thick in the vsphere. May 06, 2017 thin provisioned disks never shrink automatically when you delete data from it, lets learn how to do it. Vmware admins also need to keep an eye on capacity alerts, because thin provisioned vms grow over time. Will thinprovisioned vms shrink automatically just as they would grow automatically. Allows you to shrink a thin provisioned disk while the virtual machine is up. Converting a thin provisioned disk to a thick provisioned disk will increase the vhd size to hold the entire virtual disk size.
However, the thin disk uses only as much storage space as the disk. I have a 16 tb thick provisioned disk but the vm is only using 9tb of this. Free up esxi local drive vmfs datastore space after deleting data in a thin provisioned windows vm. I cannot use vmware tools because the virtual disk is thickprovisioned. Find answers to shrinking thick provisioned vm disk from the expert community at experts exchange. Using this feature, if a user were to delete 100 gb. End users or system administrators can use the optimize drives utility to reclaim space either by creating a manual request or by optimizing the. The disk was originally thick provisioned, so i restored the disk to another server using veeam and changed the disk type to thin. After youhave zeroed out the guest file system, you have to move the vm with storage vmotion to another datastore. Sep 11, 2011 vmware, nfs, and thin provisioning update.
Thin provisioning is an endtoend storage provisioning solution that offers justintime allocations. How to shrink decrease a virtual machines disk vmware youtube. Under a thin provisioned scheme, a disk is created with the specified size by. The argument below is now obsolete with the advent of vsphere 5 after an entertaining debate with my colleague alfredo which alfredo won i have put down a few answers to questions raised by the debate. Learn about advantages and disadvantages of thick vs. Best practices for thinprovisioning linux servers on vmware ask question. The allocated spaces of a thin provisioned virtual disk is equal to the used space plus a bunch of bytes while with a thick provisioned virtual disk the maximum capacity will be allocated despite the usage of the drive. I want to remove the unallocated space and shrink the virtual disk. If vmdk is thin provisioned you might want to shrink it back down again. In this article, were going to examine hypervs ability to resize virtual hard disks. Among them is the ability to change our minds about almost any provisioning decision.
When you create a thinprovisioned volume, you can choose the grain size for allocating space in 32 kb, 64 kb, 128 kb, or 256 kb chunks. In vmware if you thin provision a 500g disk from a 4tb datastore, the datastore reports 4tb free until you start using capacity inside that 500g disk. How does storage thin provisioning work with hyperv. At a storage level, depending on storage provider, it is possible to create either a thickprovisioned volume or a thinprovisioned. How can i reduce thin provisioned allocation of vmdk that is. The process to shrink a thin provisioned volume is the same as a thick provisioned one. How to shrink over provisioned disk on a vm hello, i run beware sphere 6.
While thin provisioning adds storage as needed, it does not work in reverse, removing unneeded storage for the vm. Vmware provides automatic virtual disk migration within the datastore cluster to avoid overflow of disk storage where thin. Your thin provisioned san will report roughly the same usage. You must shrink the filesystem and partition first. Since the compellent is thin provisioned, you can have a partition table smaller than the lun to fix a mistaken size. Shrink windows server 2008 r2 vm disk and shrink vmdk. Most thin provisioning storage arrays do not report an event when the threshold is reached. This is where the windows server 2012 r2 automatic trim feature comes into play. With this method, you first estimate how much storage the virtual machine will need for its entire life. Thin provisioning best practices for virtual server environments. When you create a thin provisioned volume, set the cache mode to readwrite to maximize performance.
In addition, you cannot undo this change with the native tools provide in hyperv. Reclaiming unused space in an oracle database pure1 support. A thin provisioning lun is usually created with less physical disk space than the size of the lun. There is no dynamic shrink of a vmdk or thinprovision reclaim of vmdks though some storage systems will provide that with drivers or. However, the thin disk commits only as much storage space as the disk needs for its initial operations.
Thin provisioning of virtual disks has been a quiet benefit to it administrators working in virtual environments. Reducing the size of a thick provisioned vmdk without vmotion. Best practices for defragmenting thin provisioned storage 2 as data is added to a thin provisioned container, such as a dynamicthin virtual disk or a lun, that container increments, usually in a justintime basis, by a chunk or number of those chunks, depending on how many chunks are needed to house all the incoming writes. With esxi, you can use two models of thin provisioning, array. If you just resize the eql volume, you will almost assuredly have data loss, as the array will just lob off the end of the volume. I was just wondering if with the latest flare code will we be seeing the option to shrink luns and not just expand luns in unisphere. Justintime allocation differs from thin provisioning. By default, esxi offers a traditional storage provisioning method for virtual machines. With the disklevel thin provisioning feature, you can create virtual disks in a thin format. Free up esxi local drive vmfs datastore space after deleting. You can use thinprovisioned storage arrays with esxi. The problem with thinprovisioned disks raxco software blog. I do not know a single system where you do not have at least 10gb of free space for os disks.
The biggest concern to thin provisioning vmware storage or hyperv storage is running out of space. Oracle asm and thin provisioning how to reclaim space. Shrinking a thin provisioned vmdk vmware communities. Thin provisioning explained and defined searchitchannel. Current used space is less than 200gb and isnt going to grow beyond that. Open up windows defrag and make sure the drive is listed as a thin provisioned volume there.
Jun, 20 thin provisioned storage can be used in 2 places. Reclaiming unused vmdk space with storage thin provisioning. Ive managed to holepunch a thin provisioned drive before after zeroing the free. The downside is that you have to carefully monitor your actual consumed storage so that a thin provisioned client doesnt attempt to grab more space than actually exists. Thin provisioning provides the guest operating system os with the illusion that the full capacity of the thinly provisioned volume is.
Most file systems back files justintime but are not thin provisioned. The thin disks will start very small and grow as data is added within the vm, however if data is logically deleted inside the vm the thin disk will not shrink. Vmware tools is a free set of drivers, services and user processes thats installed in a guest os. It requires planning for storage deployment and execution on the host and client application. Converting thick provision lazy zeroed disk to thin on.
However, asm filter driver is relatively new and there are many oracle database installations that either have not or, for various reasons can not make the switch to using asm filter driver. When you create a virtual machine, a certain amount of storage space on a datastore is provisioned to virtual disk files. How can i reduce thin provisioned allocation of vmdk that is vmfs6. You can also do os level partition resizecopy between luns to shrink it.
The default grain size is 256 kb, and is the strongly recommended option. Is there an incompatibility with nsxt and the nsx network introspection driver included with vmware tools. If the cache mode is set to none, the system cannot cache the thin provisioned metadata, which decreases performance. I wanted to know if i used storage vmotion and moved this and changed it to a thick provisioned disk would i then be able to shrink the vmdk file. In virtual environments, there can even be a mix of both thin and thick provisioned storage. Normally, this would clear all unused disk space, but strangely this doesnt work for thin provisioned disk. Monitor the use of space on thinprovisioned luns to avoid running out of physical space. Above, we mentioned a solution to shrink thinprovisioned disks manually. Under a thin provisioned scheme, a disk is created with the specified size by preallocating none or partial storage space for it. A similar technique can be used to shrink thinprovisioned guest hard disks. This is the case with both thick provisioned and thin provisioned disks.
Thin provisioning is a technology employed by storage products for optimized resource utilization. This is a production server, so the utmost care must be taken. After you convert the disk, it grows to its full capacity and occupies the entire datastore space provisioned to it during the disks creation. How can i reduce thin provisioned allocation of vmdk that. Nov 24, 2014 howto shrink a thin provisioned virtual disk vmdk thin provisioned disks are a great feature to save capacity as you virtual machines filesystem will never use the full capacity. Threshold notification is a required function to alert the host and client application of the storage space consumption state. Convert thick provisioned disk to thin and vice versa on esxi. Thin provisioning this method contrast with thick provisioning and helps you eliminate storage underutilization problems by allocating storage space in a flexible ondemand manner. Now we will look at how to optimize storage performance with your virtual machine template and discuss the different configuration options available to you. Proper use of hyperv dynamic disks 24 jul 20 by eric siron one of the great unsung heroes of virtualization is the thinprovisioned virtual disk, known in. Provisioning thin luns can lead to an over provisioned capacity situation very easily, but then after performing house keeping on the host we find a 2tb lun. If it is not listed as a thin provisioned volume, talk to your storage admin. Thin provisioning offers more efficiency where the amount of resource used is much smaller than allocated, so that the benefit of providing only the resource needed exceeds the cost of the virtualization technology used. How to shrink decrease a virtual machines disk vmware.
Will thin provisioned vms shrink automatically just as they would grow automatically. Shrinking a thin provisioned volume is only supported in v4 or higher. Reducing the size of a thick provisioned vmdk without. By default, the type of the newly created virtual disk is thick provision lazy zeroed format, which is adversely affects the future performance of the system. Best practices for defragmenting thin provisioned storage.
Reclaim thin provisioned space punchzero virtual journeyman. Reducing the size of a thick provisioned vmdk without vmotion, copy or clone. Thin provisioning best practices for virtual server. As your datastore grows or if you use storage vmotion to migrate virtual machines to a thinprovisioned lun, the host communicates with the lun and warns you about breaches in physical space and about outofspace conditions. We have a storage challenge in our organization, and i intend to reduce the storage space assigned to the vm. We have now covered how to optimize storage performance for sql server and windows at the operating system level. A virtual guest drive could be thick provisioned but the underlying storage could be thin provisioned known as thick on thin. Thin provisioning can aid storage capacity management by allowing storage professionals to optimise their purchases of disk space by allowing a lun volume to be provisioned without requiring the. The issue of course is that the compellent can not see what the os has done, except as provided by the server agent. Windows deletes a file by removing the referencespointers in the file allocation table. Reclaim disk space from thin provisioned disks rickard nobel. Advanced vmdk size reclamation for thinprovisioned disks. Thin provisioned disks are a great feature to save capacity as you virtual machines filesystem will never use the full capacity. What complications can arise when thin provisioning vmware.
The argument below is now obsolete with the advent of vsphere 5. Best practices for defragmenting thin provisioned storage 2 as data is added to a thin provisioned container, such as a dynamic thin virtual disk or a lun, that container increments, usually in a justintime basis, by a chunk or number of those chunks, depending on how many chunks are needed to house all the incoming writes. In theory, i would just create big disks for each machine and use thin provisioning. Thin provisioning allows you to overcommit your storage space. How to shrink a thickprovisioned disk vmware communities. Nov 07, 20 before we can use vmkfstools to shrink the vmdk file we must zero out any unused space on the thin provisioned disk.
Once this is done you shrink the size of the vhd file. Shrinking thick provisioned vm disk solutions experts. The ugly truth about thin provisioning and the ntfs silent. Best practices for thinprovisioning linux servers on vmware. Download sdelete onto the vm you want to shrink and run the following command, replacing drive. Windows server thin provisioning features serve as interfaces between the thin provisioning capable storage and the host server. The thin provisioned disk starts small and at first, uses just as much storage space as it needs for its initial operations. In case of a unixoide os linux, freebsd, solaris, use dd. In the recent past of thick provisioned storage as the only option still common in nonvirtualized, local storage environments, administrators made educated guesses about the amount of disk space their systems would need. How to reclaim disk space from virtual machines with thin virtual disks in vmware vsphere. Please note that i dont want to focus on reclaiming space from underlaying luns.
Shrinking a thin provisioned vmfs vvolume dell community. A common issue with thin disks is that the size will grow when required, but never shrink. Feb 03, 2018 in this video we will shrink a vmware virtual machines vmdk by 10 gb. Reclaiming thin provisioned storage space with vmware unmap. Having thin provisioned disk is usually no longer a performance problem so it is a valid design choice even in production. In this article, we are going to consider the storage preallocation aspect of virtual disk settings in detail and find out what thick and thin provisioning are, how they differ, and which of these storage preallocation types is better for your infrastructure. How to manage and configure bitlocker drive encryption. Find answers to how to shrink a virtual disk esxi 5.
For a thin virtual disk, esxi provisions the entire space required for the disks current and future activities, for example 40gb. However, there is one more way to manage your virtual disks both thinprovisioned and thickprovisioned, if you use a datastore cluster in vsphere. I am not considering databases, applications or fileservers which will grow constantly. Thin provisioning makes it possible to allocate far more space to a virtual hard disk a vmdk file than what is physically available on the storage array. Your thin provisioned san will still report 4tb in that logical unit and 34tb total capacity. Storage space reclamation esxi supports the space reclamation command, also called scsi unmap command, that originates from a vmfs datastore or a vm guest operating system.
300 142 74 1017 1364 521 1299 523 954 1188 1088 306 1117 813 1144 1086 550 842 387 613 1202 1499 1135 967 840 995 431 1263 898 441 1494 340 1274 1004 1471 669 742 1490 429 1206 392 1427 216 985 855 600 549 1106 1359 1239