Citrix Provisioning Services has been invigorated with new storage optimisations. Every storage vendor that got into business providing a solution to I/O problems may have to think twice about the value they add given new services within PVS. But, does that mean that creating a viable PVS service has become a breeze? In Preventing Possible PVS Performance Pain Points we set out to look at the performance of PVS server including networking, host configuration, the importance of being earnest about memory, the good, bad and ugly of RAM+HDD write cache and Windows Storage or hyper-converged environments, migration and availability.

1. Jim Moyle, Andrew Wood
Preventing Possible PVS Performance Pain Points

2. 2
#syn306
#citrixsynergy

3. Please allow us to introduce ourselves…
Jim Moyle
@jimmoyle
Andrew Wood
@gilwood_cs
IOPS Junky, Demo Upgrade Specialist
Badge Collector

4. State of the VDI/SBC Union 2015
http://www.projectvrc.team/white-papers

6. PVS Architecture
License Server
SQL
Database
Shared
Storage
Provisioning Servers
Provisioning Services Farm
Provisioning Servers
Site A Site B
Device
Collections
Device
Collections
Device
Collections
Device
Collections
Device
Collections
Device
Collections
http://lnk.glwdcs.tv/1Qw5I3d

7. Storage with Citrix PVS
Operating System
(Win 7, 8, 10),
2008R2/2012R2
User/Department
Applications
User Profiles/
Settings
Corporate
Applications
User Data
(Docs,Spreadsheets
,Pictures of Family)
PVS vDisk PVS Write Cache Personal vDisk AppDisk
Home
Directories
Hypervisor
SMB/Local NFS/Local NFS/SMB SMB SMB
10GB Ethernet Other

9. PVS Cache Types

10. RAM Overflow to HDD - What Can Overflow?
PVS Non
Paged
memory
Pool
Page File Space for
Crash Dump
Anti-Virus
Definitions
Log Files
Hard Drive associated with target VM
In RAM On Disk
Overflow
File
RAM

11. Many say “take the raw
performance counter details for
Non Paged Pool memory and
assume this is the size of the
cache”. That’s like looking into a
can of beans and trying
to determine which one gave you
gas.

12. Using WPA to Really Dig Into PVS
https://www.citrix.com/blogs/2015/08/19/digging-into-pvs-with-poolmon-and-wpa/

14. Generic Events

15. File IO Events

16. On Reporting Cache Utilization Easily
Community Tool to Exposes Counters is Available
• PVS RAM cache size (MB)
• PVS metadata size (MB)
• PVS Write Cache VHD disk size (MB)
• PVS Ram Cache Percent used.
http://lnk.glwdcs.tv/1qATRvk

17. Iometer W/C Local Disk - SSD

19. Pagefile.

20. Copying a 1GB file onto c:

21. 1GB Test File – with PVS 7.1

22. 1GB Test File – with PVS 7.8

23. No Spill

24. Delete test file, TRIM?

25. 10GB Test File

26. 10GB File Overflow to Disk

27. Where the test file ends up…

29. https://technet.microsoft.com/en-us/itpro/windows/keep-secure/windows-10-mobile-security-guide

30. Turn Off ASLR?
You can forcibly enable or disable ASLR for all executables
and libraries:
If you’re still on Windows XP –
HKLMSYSTEMCurrentControlSetControlSessio
n ManagerMemory ManagementMoveImages
specifying "MoveImages"=dword:00000000 to disable it
system-wide (current user).
Another option is to use the "Enhanced Mitigation
Experience Toolkit" (EMET):
https://technet.microsoft.com/en-us/security/jj653751
https://support.microsoft.com/en-gb/kb/2458544
allowing to enable/disable ASLR it on a system or process
basis.

32. “When a decision is required on whether or
not a server should be provisioned as (or
migrated to) a virtual server, several criteria
should be considered. In each case the
amount of use, potential hardware
utilization, number of users, and any other
special hardware requirements will have to
be reviewed before a decision is made”
Ron Oglesby

33. Is CPU a bottleneck for PVS?
3

34. 1Gb n/w ~ 20,000 IOPS @ 4K Block size

35. Windows Block Size

37. 4BriForum | © TechTarget

38. 4BriForum | © TechTarget

39. Show BDM cached in VM

40. 4

41. 4

44. “I just need lots of fast storage right?
In a virtualised environment, fast storage
fixes everything.”
Many people who talk to Jim

45. Getting RAM Right

46. http://support.citrix.com/article/CTX125126

47. SYSTEM CACHE RAM = 512MB + #active vdisks * avg data read from vdisk
For example, assume the following configuration:
• A running Provisioning Services server under load showing 2 GB of
committed memory
• 4 unique vDisk files hosting Windows 7 for various target devices
• 2 GB of data read on average from each vDisk
• System Cache RAM = 512 MB + (4 * 2 GB) = 8.5 GB
• Total RAM = 2 GB + 8.5 GB = 10.5 GB

48. Multi-threaded BNI Stack
IP Acquisition
Bootstrap
download
PVS Logon
Process
Single Read
Mode
BNIStack/MIO
http://support.citrix.com/article/CTX136378
https://www.citrix.com/blogs/2016/01/12/turbo-charging-boot-times-with-pvs-7-7/

49. That’s not to say
storage isn’t important

51. Reducing Creation and Merge Time
http://blog.itvce.com/2016/01/11/citrix-provisioning-services-pvs-7-6-vs-7-7-vhd-vs-
vhdx-and-scale-out-file-server-update

52. More Ports vs More Threads
Ports Range Threads per
port
Average Boot
time first 10
Guest VMs
Average Boot
time last 10
Guest VMs
Baseline 6910 to 6945 40 49.8 83.2
Test 1 6910 to 6945 8 28.2 60.2
Test 2 6910 to 6968 8 29.4 48.9
Test 3** 6910 to 6968 8 36.1 92.5
https://www.citrix.com/blogs/2016/03/30/updated-guidance-on-pvs-ports-and-threads/
Jeff Qiu
“# of ports” x “# of threads/port” = “max clients”.
**I/O limit set to 0

53. Traditional Storage
Compute/App
Servers
Storage
Controllers
Hyper-Converged
Compute/App
Servers combining
local resources

55. Local Storage vDisk Stores
– No networking layer
– Removal of Point Failure
– No storage service to configure
– Increases storage requirements
– Synchronisation of stores

56. RoboCopy vs DFS-R vs A.N.Other?
PVS-A PVS-B PVS-B
vDisk on Local Storage vDisk on Local Storage vDisk on Local Storage
DFS-R Full Mesh Replica

59. Pod Based Architecture
6

61. http://www.xkcd.com/

62. Monitoring and expand out