Hello Metze, I have recently been using Samba share as NAS storage, and after enabling CONTINUOUS AVAILABILITY, I noticed a significant drop in performance. My file operations involve a lot of open/close scenarios. After investigation, I found that enabling CONTINUOUS AVAILABILITY will cause Windows clients to disable handle caching.
I noticed that you mentioned this issue on the Samba CIFS-PROTOCOL mailing list (#Q6- TrackingID#2311070040010094), but I couldn't find an effective response. I checked the Windows Group Policy documentation and found that in the CA scenario, handle caching is disabled by default, but it can be manually enabled. Here is the documentation : https://learn.microsoft.com/en-us/windows/client-management/mdm/policy-csp-admx-lanmanworkstation#pol_enablehandlecachingforcafiles . 3.2.4.3.5 Application Requests Creating a File Opened for Durable Operation > > ... > > - If TreeConnect.IsCAShare is TRUE, the client MUST set the > SMB2_DHANDLE_FLAG_PERSISTENT bit in the Flags field. Otherwise, the > client SHOULD > perform one of the following: > > - Request a batch oplock by setting RequestedOplockLevel in the > create request to > SMB2_OPLOCK_LEVEL_BATCH. > > - Request a handle caching lease by including an > SMB2_CREATE_REQUEST_LEASE or > SMB2_CREATE_REQUEST_LEASE_V2 Create Context in the create request > with a > LeaseState that includes SMB2_LEASE_HANDLE_CACHING. > > ... > > Question 6: > From the documentation the above is the only reference that is impacted by > SMB2_SHARE_CAP_CONTINUOUS_AVAILABILITY and it seems that it implicitly > disables handle caching, is that really true? > > And SMB2_DHANDLE_FLAG_PERSISTENT doesn't seem to be impacted by > SMB2_GLOBAL_CAP_PERSISTENT_HANDLES, which is strange. > Can you please cross-check this? > >
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