How to update Content Library configuration settings in the vCenter Appliance
Article ID: 320873
Updated On:
Products
Issue/Introduction
This article provides an overview of the Content Library settings in a vCenter Server, detailing how these settings influence the number of items a Publisher library can simultaneously synchronize with Subscriber libraries. The capacity for a Publisher to service Subscribers is contingent on these settings, along with the total number and size of files synchronized. There is no fixed limit to the number of subscribers, as it varies based on the described configurations. This article simply aims to assist users in optimizing these settings to achieve an effective Content Library configuration.
Environment
VMware vCenter Server 8.0.x
VMware vCenter Server 7.0.x
VMware vCenter Server 6.7.x
Resolution
Content Library Settings
Library Auto Sync Enabled
This setting determines whether a Subscriber library will automatically synchronize with its Publisher—either immediately or when needed. This applies to ALL of the Subscriber libraries in a vCenter Server, but has no effect on Publisher libraries.
Library Auto Sync Refresh Interval (minutes)
Controls how often Subscriber libraries will automatically try to sync with their Publisher, only if auto sync is enabled. This only applies to the window of time defined in the "Auto Sync Start/Stop Hour" below.
Library Auto Sync Setting Refresh Interval (seconds)
Controls how often content library looks for settings changes made here and applies them. This does not apply to settings which specifically note that they require a service restart.
Library Auto Sync Start Hour
Hour of the day in UTC that the Subscriber libraries on a vCenter will start attempting to auto-sync. A Publisher with a lot of subscribers beginning to sync at same time will cause a bottleneck in concurrent transfer sessions. Use this setting to stagger the synchronization window allocated to each Subscriber.
Library Auto Sync Stop Hour
Hour of the day in UTC that the Subscriber libraries on a vCenter will stop attempting to auto-sync. The stop hour will not cancel existing sync tasks.
Library Maximum Concurrent Sync Items
Controls how many library items (not files) can be concurrently synchronized to a subscriber. This setting has no direct effect on Publisher libraries.
Max concurrent NFC transfers per ESX host
This setting governs the number of concurrent NFC (Network File Copy) sessions that can be opened to a single ESXi host for transferring items. Each file within a library item utilizes one NFC connection, with larger files like VMDKs and ISO images occupying an NFC session for a longer duration compared to OVF or NVRAM files.
For instance, consider a content library that stores its items on a VMFS datastore accessible by three ESXi hosts. This configuration allows for a total of 24 concurrent NFC sessions available for item transfers to and from that datastore.
This limit is shared across all content library operations within a vCenter, including OVF template deployments, item imports and exports, and copy operations.
Maximum Bandwidth Consumption
Limits the bandwidth of all transfer sessions in Mbits/s. 0 means unlimited.
Maximum Number of Concurrent Priority Transfers
Same as concurrent transfers below, except it only affects "OVF" file types. VMDK, NVRAM, and ISO files are not included.
Setting this value too high may cause library items to begin syncing when other (non-priority) files from the same item lack an available transfer thread, resulting in timeouts.
Maximum Number of Concurrent Transfers
Directly controls the amount of file transfers (not library item sync tasks) that can happen simultaneously on the vCenter.
For Publishers, it dictates the total amount of concurrent files it can be transferring to all subscribers.
For Subscribers, it dictates the total amount of concurrent files it can ask the publisher to sync.
While this setting does not directly affect the number of concurrent library item sync tasks, it does have an indirect effect on them. Content library will not start a new item sync task if there are no threads available for any of the files in that item. For example, if the number of files in each library item is 3, then setting this from 1-3 will allow 1 library item to sync at a time, 4-6 would allow for 2 items to sync at the same time, etc..
Additional Information
Customizing the Content Library settings can be done via an SSH session to the vCenter Appliance when there is no access to vSphere Client.
/etc/vmware-content-library/config/cls-config.properties
- Library Auto Sync Enabled: library.syncEnabled
- Library Auto Sync Refresh Interval (minutes): library.subscriptionRefreshInterval
- Library Auto Sync Setting Refresh Interval (seconds): library.sync.refreshPeriod
- Library Auto Sync Start Hour: library.garbageCollect.startHour
- Library Auto Sync Stop Hour: library.garbageCollect.stopHour
- Library Maximum Concurrent Sync Items: library.sync.maxConcurrentVcspWorkers
/etc/vmware-content-library/config/ts-config.properties
- Max concurrent NFC transfers per ESX host: transfer.nfcClient.max.concurrent.transfers.per.host
- Maximum Bandwidth Consumption: transfer.throttling.bandwidth.total.mbitsec
- Maximum Number of Concurrent Priority Transfers: transfer.threads.priorityPoolSize
- Maximum Number of Concurrent Transfers: transfer.threads.poolSize
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