{"id":488,"date":"2018-08-30T22:55:23","date_gmt":"2018-08-30T19:55:23","guid":{"rendered":"https:\/\/blog.arcak.net\/?p=448"},"modified":"2018-09-03T09:18:04","modified_gmt":"2018-09-03T06:18:04","slug":"vmware-vsan-storage-policy-based-management-spbm","status":"publish","type":"post","link":"https:\/\/blog.arcak.net\/index.php\/2018\/08\/30\/vmware-vsan-storage-policy-based-management-spbm\/","title":{"rendered":"VMware vSan Storage Policy Based Management (SPBM)"},"content":{"rendered":"

I’ll try to elaborate on the Storage Policy Based Management (SPBM)<\/strong>\u00a0what\u00a0I’ve\u00a0briefly describe in my previous article<\/strong><\/a>.\u00a0\u00a0Protection types specified in\u00a0SPBM <\/strong>are Datastore Default<\/strong>, per-VM<\/strong> and per-vmdk.<\/strong><\/p>\n

You can review Storage Policy Rules in\u00a0vendor resources<\/a><\/strong> for further details.<\/p>\n

\"\"<\/p>\n

<\/p>\n

Primary level of failures to tolerate (PFTT): <\/span><\/strong>De<\/span>fines the number of server and device failures that a virtual machine object can tolerate. If fault tolerance for\u00a0n<\/strong> is required, each data is written to the n + 1 location, including the RAID5<\/strong> and\u00a0RAID6<\/strong>\u00a0parity data. If the storage policy is not selected when creating a virtual server, the default policy is chosen by default. If Fault Domain structure is present, it needs up to 2n + 1<\/strong> capacity. i.e for two Fault Domains\u00a02 (2) + 1 = 5<\/strong> unit capacity is required. <\/span><\/p>\n

In the Stretched Cluster (SC)<\/strong> structure, this value identifies the virtual server objects that can be tolerated. PFTT<\/strong> and SFTT<\/strong> are used simultaneously to ensure data protection between both locations. In\u00a0SC<\/strong> structure,<\/strong> the PFTT<\/strong> maximum value is 1.
\n<\/span><\/p>\n

Secondary level of failures to tolerate (SFTT): <\/strong>In\u00a0Stretched Cluster<\/strong> structure, this rule determines the number of servers that can be tolerated in the second location after reaching the number of PFTT<\/strong> in a place (after the location becomes unavailable<\/strong>). For example, if PFTT = 1 an<\/strong>d SFTT<\/strong> = 2<\/strong> and access to the first location are stopped, the cluster can tolerate up to 2<\/strong> servers loss at the second location.<\/span><\/span><\/p>\n

Data Locality: <\/strong>It operates\u00a0<\/span>In<\/span>\u00a0Stretched Cluster<\/span><\/strong>\u00a0Structure<\/strong> when PFTT = 0 <\/strong>is set. None, Preferred<\/strong>, or Secondary <\/strong>options are available. It’s a solution to reach the high performance with low delay thus virtual machines can be restricted to site where they need to operate. The default value is None<\/strong>.<\/span><\/span><\/p>\n

Failure Tolerance Method: <\/strong>Determines whether the data replication method will be either for performance or capacity-oriented.\u00a0RAID1 <\/strong>is performance-oriented and needs more capacity, and if 4<\/strong> or more servers <\/strong>are selected as\u00a0RAID5\/6 (Erasure Codin<\/strong>g) and PFTT<\/strong> = 1<\/strong>, then the capacity is achieved with\u00a0RAID5<\/strong>. If 6 <\/strong>or more server<\/strong>s are selected as RAID5\/6 (Erasure Coding) <\/strong>and PFTT = 2,<\/strong>\u00a0capacity-oriented RAID6 <\/strong>with resistant for loss of one more object\u00a0 is obtained.<\/span><\/span><\/p>\n

When SFTT <\/strong>is configured in Stretched Cluster (SC)<\/strong> structure, this value will affect\u00a0only the number of servers that can be tolerated, not the raid structure.<\/span><\/p>\n

Number of disk stripes per object: <\/strong>Determines how many devices each virtual machine object will be written as. The default is 1<\/strong>, larger values give better performance but use more system resources. <\/span>Changing the default value is not recommended.<\/span>\u00a0<\/strong><\/span><\/p>\n

Flash Read Cache reservati<\/strong>on:<\/span><\/strong> By default, cache reservation<\/strong> is fairly shared between all objects and the value\u00a0 does not need to be changed. Can be used for specific problem-solving purposes. The default value is 0%<\/strong> and the maximum value is 100%.<\/strong><\/span><\/span><\/p>\n

Force Provisioning: <\/strong>W<\/span>hen this rule is active, the new virtual machine can be created even if\u00a0PFTT, Number of disk <\/strong>stripes per object and Flash read cache reservation<\/strong> policies requirements are not met. In a healthy vSan environment, this rule should not be activated and should only be used for new installation in cases of disaster-like urgencies.<\/span><\/span><\/p>\n

Object Space Reservation: <\/strong>Sp<\/span>ecifies the area in which Virtual server disk (VMDK<\/strong>) objects occupy. Default value is 0% (thin) <\/strong>and the maximum value is 100% (thick)<\/strong><\/span><\/span><\/p>\n

Disable Object checks<\/strong>um<\/strong>: By default, this value is defined as No<\/strong>. vSan<\/b>\u00a0has mechanisms that control end-to-end data integrity and automatically repair when corruption occurs.\u00a0If this value is defined as Yes<\/strong>, data integrity cannot be validated.<\/span><\/span><\/p>\n

IOPS limit for object: <\/strong>defined on an object (e.g. VMDK)<\/strong> determines the IOPS limit. When calculating IOPS<\/strong>, read and write operations are taken into place as equivalent, but cache hit rate<\/strong> and sequentiality<\/strong> are not considered . If a disk’s IOPS limit is exceeded then\u00a0<\/strong>I\/O operations are limited. If\u00a0IOPS limit for object<\/strong> = 0 <\/strong>then the limits are not mandatory. vSan allows the object to double the IOPS limit value when the first second of the operation or after a period of inactivity<\/span><\/span><\/p>\n

* As a Bonus, you can access\u00a0SPBM Cheat Sheet here<\/strong><\/a>, which includes the policies you need most in Stretched Cluster<\/strong> structure.<\/p>\n

\n","protected":false},"excerpt":{"rendered":"

I’ll try to elaborate on the Storage Policy Based Management (SPBM)\u00a0what\u00a0I’ve\u00a0briefly describe in my previous article.\u00a0\u00a0Protection types specified in\u00a0SPBM are Datastore Default, per-VM and per-vmdk. You can review Storage Policy Rules in\u00a0vendor resources for further details.<\/p>\n","protected":false},"author":1,"featured_media":0,"comment_status":"open","ping_status":"open","sticky":false,"template":"","format":"standard","meta":{"footnotes":""},"categories":[193,165,167],"tags":[],"class_list":["post-488","post","type-post","status-publish","format-standard","hentry","category-hyperconverged-infrastructure","category-virtualization","category-vmware"],"_links":{"self":[{"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/posts\/488"}],"collection":[{"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/posts"}],"about":[{"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/types\/post"}],"author":[{"embeddable":true,"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/users\/1"}],"replies":[{"embeddable":true,"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/comments?post=488"}],"version-history":[{"count":7,"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/posts\/488\/revisions"}],"predecessor-version":[{"id":544,"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/posts\/488\/revisions\/544"}],"wp:attachment":[{"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/media?parent=488"}],"wp:term":[{"taxonomy":"category","embeddable":true,"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/categories?post=488"},{"taxonomy":"post_tag","embeddable":true,"href":"https:\/\/blog.arcak.net\/index.php\/wp-json\/wp\/v2\/tags?post=488"}],"curies":[{"name":"wp","href":"https:\/\/api.w.org\/{rel}","templated":true}]}}