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Volume mapping layout
43 Dell EMC SC Series: Best Practices with VMware vSphere | 2060-M-BP-V
remaining hosts. The sudden reduction in overall memory could cause a sudden increase in paging activity
that could overload the datastore, causing a storage performance decrease.
Second, that datastore could become a single point of failure. Operating systems are not very tolerant of
unexpected disk drive removal. If an administrator were to accidentally unmap the page file volume, the
number of virtual machines within the failure domain would be isolated to a subset of the virtual machines.
9.1.3 Separation of virtual machine swap files
Each virtual machine also has a memory swap file in its home directory used when the VMware Tools balloon
driver is unable to reclaim enough memory. In other words, the virtual machine swap (VSWP) file is only used
as a last resort by the ESXi host to reclaim memory. VMware recommends keeping the VSWP files in the
virtual machine home directories. However, if needed, it is also possible to relocate the VSWP file to a
dedicated volume. While doing this technique may help to reduce snapshot sizes and preserve replication
bandwidth, it should only be done under the guidance of VMware support.
9.1.4 Virtual machine placement
This example technique gives a great deal of flexibility when building out the storage architecture in the
environment, while keeping with the basic concepts discussed above. The following example layout meets
most virtual infrastructure needs because it adds the flexibility of being able to add RDMs to virtual machines
later if needed. The key to this technique is reserving LUN numbers in the middle of the LUN sequence to
help better organize the virtual machines.
An example of this technique is as follows:
LUN0 - Boot LUN for ESXi (When booting from SAN)
LUN1 – Templates, ISOs, General Storage
LUN10 – OS, DATA (drives C, D, and E)
LUN11 – Page file (Paired with LUN10) for operating system paging files [If necessary]
LUN12 - LUN19 - Reserved LUNs for virtual machine RDMs for machines in this group
LUN20 – OS, DATA (drives C, D, and E)
LUN21 – Page file (Paired with LUN20) for operating system paging files [If wanted]
LUN22 - LUN29 - Reserved LUNs for virtual machine RDMs for machines in this group