Tintri: Best Practices for Snapshot Heavy Environments

Transcription

1 Tintri: Best Practices for Snapshot Heavy Environments Tomer Hagay, Tintri #vmworld VAP3915BUS #VAP3915BUS

2 About Myself Tomer Hagay Director, Technical Marketing - Tintri Technical Advisor to the European Commission Over 2 decades of IT experiences, focused on cloud automation, virtualization, service orchestration and datacenter management 10 Cisco prior to Tintri 2

3 The Story Or: Why did I sign up to deliver a session about snapshots? Company restructuring exposed new challenges vsphere Snapshots became a major bottleneck This session covers findings from production environments, lab research and important facts 20 % Tintri Operations 80 % Tech Marketing 3

4 Snapshot Situation - Example Mission Critical VM Size ~17TB vsphere 5.5 Snapshot taken in 2014 Yes, it ran for 11 days 4

5 Snapshots Definition A snapshot is a file-based representation of the state of a virtual machine at a given time Consistency: Crash Consistent - Same concept as if pulling the power plug out of the back of the server Application Consistent - Server will be in the same state as in after a clean OS reboot Type: Storage array managed or Hypervisor managed 5

6 VMware Best practices for using snapshots in the vsphere environment ( ) Do not use snapshots as backups The snapshot file is only a change log of the original virtual disk. Maximum of 32 snapshots are supported in a chain However, for a better performance use only 2 to 3 snapshots. Do not use a single snapshot for more than 72 hours The snapshot file continues to grow in size when it is retained for a longer period. This can cause the snapshot storage location to run out of space and impact the system performance. 6

7 vsphere Snapshots Hierarchy Every snapshot creates a delta file New write operations are committed to the latest delta Previous files become read only 7

8 VM Created

9 OS Installed Grass Available Space OS

10 OS Installed Sky, Landscape User and Logs Available Space Application OS

11 Flat File Content Available Space OS

12 Delta File Content Application

13 Lab Time: Performance 13

14 vsphere Snapshots Inside the Delta File 14

15 Lab Summary vsphere snapshots add a significant performance overhead (as expected) Changes the Good put vs Throughput ratio Creates additional storage and host operation VM Write operation performance is impacted as well Block size have a major difference 15

16 Removing That Big ol Snapshot Mission Critical VM Size ~17TB vsphere 5.5 Snapshot taken in

17 Snapshot Removal Submitted Now What? Space IOPS 17

18 Snapshot Removal Submitted Now What? Space Latency 18

19 Snapshot Removal - The Good News From ESX4.0 Update 2 onwards, ESX incorporates improved consolidation procedures which lessen the demand of free space You are able to consolidate virtual machine delta disks even while minimal free space on your datastore is available vsphere 6 and above improves on Snapshot consolidation However Check your array level snapshots Make sure the array doesn t fill up due to the high change rate 19

20 Snapshot Removal Submitted Longer term 20

21 vsphere 6.7 Instant Clone Introduced by VMware as a preview in vsphere 6.7 Allows an immediate VM clone, including memory state Available via API only New VM created at the same state of the original VM Any downsides? Let s take a look 21

22 Lab Time: Instant Clone 22

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24 THANK YOU! #vmworld #VAP3915 BUS