Sorry for delayed response, I ran DTRace during PST migrations but logs do not really say how much or what changes they made to mailbox size.
Directory service reads EV settings from SQL:
8398 11:20:59.019 [8164] (DirectoryService) <7844> EV:M DirectoryService: ADO: SELECT se.SiteEntryId,se.SiteName,se.DefaultFilterId,se.DefaultPublicFolderFilterId,se.DefaultRetentionCategoryId,se.DefaultWebAppURL,se.DefaultArchivingSchedule,se.DefaultIndexingLevel,se.SiteDescription,se.MessageOfTheDay,se.AutoEnableMailboxes,se.AutoEnableInitSuspend,se.SiteAdminNote,se.AdminMinVersion,se.UsersCanDeleteItems,se.DeleteExpiredItems,se.DeleteProtected,se.DefaultPublicFolderSchedule,se.DefaultExpirySchedule,se.DesktopDoubleClickView,se.ExpiryDateBasis,se.ExpiryReportMode,se.SiteAccountDistinguishedName,se.SiteAccountMailboxAlias,se.SiteDirectoryEntryId,se.SiteVaultLimitSize,se.SiteVaultLimitOperation,se.IndexMode,se.AllClientsAtSiteVersion,se.DefaultPFRetentionCategoryId,se.SPSExcludeFileTypes,se.SPSItemSize,se.SiteVaultNotifySize,se.SiteVaultNotifyOperation,se.QuotaNotificationFreq,se.CreateStructuredArchives,se.EnableCodeMonitoring,se.PSTHoldingDirectory,se.PSTHoldingLimit,se.DumpsterEnabled,se.DumpsterPeriod,se.RetainArchiveHistory FROM SiteEntry se WHERE se.SiteEntryId = ? |
8489 11:20:59.613 [8164] (DirectoryService) <7844> EV:M DirectoryService: ADO: SELECT poPolicyEntryId,poType,poIsADefaultPolicy,poName,poDescription,SiteEntryId,excFilterId,excWebAppURL,excIndexingLevel,excAutoEnableMailboxes,excAutoEnableInitSuspend,excUsersCanDeleteItems,excDesktopDoubleClickView,excShortcutDetail,excAdditionalShortcutProperties,excEnableMailboxMsgFileName,excDisableMailboxMsgFileName,excQuotaApproachingMsgFileName,excQuotaExceededMsgFileName,excShortcutTextSettingsFileName,FilterName,FilterDescription,InactivityPeriod,InactivityPeriodUnits,DeleteNoArchive,DeleteAfterArchive,LockDeleteAfterArchive,CreateShortcutAfterArchive,LockCreateShortcutAfterArchive,ProcessUnreadMail,FilterSiteEntryId,LockProcessUnreadMail,LockDeleteAfterArchive,LockCreateShortcutAfterArchive,LockUseInactivityPeriod,UseInactivityPeriod,FilterAdminNote,MaxMsgPerUserPerSchedule,PercentageOfQuota,ArchiveLock,ShortcutInactivityPeriod,ShortcutInactivityUnits,RestoredItemsInactivtyPeriod,RestoredItemsInactivtyUnits,AllowSubFolderInheritance,LockSubFolderInheritance,AMinAgeLargeItems,AMinAgeLargeItemsUnits,AMinSizeLargeItems,ASizePriority,QMinAgeThresholdPeriod,QMinAgeThresholdUnits,QMinSizeLargeItems,QSizePriority,ExpandDistLists,ExpandDistListsLock,pstRetentionCategoryId,pstLanguage,pstMailboxFolder,pstShortcutMode,pstIncludeDeletedItems,pstSetPstHidden,pstSetPstReadOnly,pstCompactPst,pstDeletePst,pstArchiveNonExpiredCalItems,pstCancelMbxAutoArchive,pstMergePstFolders,pstRemoveFromProfile,pstAdjustExchangeQuotas,pstShortcutAgePeriod,pstShortcutAgeUnit,pstIgnoreCompliance,pstClientSearchRestricted,pstExpandOfflineVault,ProcessMsgsWithAttachmentsOnly,OrphanedShortcutRun,pstDefineCustomProperties,SCMoveUpdateItemLocation,SCMoveMoveUpdateRetCatUser,SCMoveMoveUpdateRetCat,UseQuotaLimit FROM ExchangePolicyView WHERE ExchangePolicyView.poType = 3 AND ExchangePolicyView.SiteEntryId = ? ORDER BY poName |
8918 11:21:01.941 [8164] (DirectoryService) <3868> EV:M DirectoryService: ADO: SELECT poPolicyEntryId,poType,poIsADefaultPolicy,poName,poDescription,SiteEntryId,pstRetentionCategoryId,pstLanguage,pstMailboxFolder,pstShortcutMode,pstIncludeDeletedItems,pstSetPstHidden,pstSetPstReadOnly,pstCompactPst,pstDeletePst,pstArchiveNonExpiredCalItems,pstCancelMbxAutoArchive,pstMergePstFolders,pstRemoveFromProfile,pstAdjustExchangeQuotas,pstShortcutAgePeriod,pstShortcutAgeUnit FROM ExchangePolicyView WHERE ExchangePolicyView.poType = 6 AND ExchangePolicyView.SiteEntryId = ? ORDER BY poName |
8963 11:21:01.973 [8164] (DirectoryService) <3868> EV:M DirectoryService: ADO: SELECT eme.ExchangeMailboxEntryId,eme.MbxIdentity,eme.LegacyMbxDN,eme.MbxDisplayName,eme.MbxAlias,eme.MbxNTUser,eme.MbxNTDomain,eme.MbxArchivingState,eme.MbxExchangeState,eme.ExchangeMbxType,eme.MbxWarningLimit,eme.MbxSendLimit,eme.MbxReceiveLimit,eme.MbxSize,eme.MbxItemCount,eme.DefaultVaultId,eme.City,eme.Company,eme.Country,eme.Department,eme.EmployeeType,eme.FirstName,eme.LastName,eme.Office,eme.State,eme.Title,eme.UseQuota,eme.LastModified,eme.EnabledPstImport,eme.PolicyEntryId,eme.PSTPolicyEntryId,eme.PolicyTargetGroupEntryId,eme.PolicyTargetMemberEntryId,eme.ADMbxDN,eme.ExchMbxGUID,eme.MbxStoreIdentity,eme.ADMbxFlags,eme.DesktopPolicyEntryId,eme.MbxSuspended,eme.MoveArchiveShortcutSubtask,ese.ExchangeServerEntryId,ese.SiteEntryId,ese.ExchangeComputer,ese.ExchangeServerADSPath,ese.ExchangeLegacyDN,ese.ExchangeVersion,ese.ExchangeServicePack,ese.ExchangeServerIdentity,ese.ExchangeServerFQDN,ese.ExchangeServerGCOverride,ese.OranizationEntryId,ese.ManualAdminSecurityDesc,ese.OverrideFlags,ese.DefVaultStoreEntryId,ese.DefIndexingServiceEntryId,ese.ExchServerVersion,ese.ADExchSvrDN,ese.ExtendedConfigurationData,ese.MbxArchiveScannedUTC,ese.MbxArchiveSubmittedUTC,ese.AddedToEVUTC FROM ExchangeMailboxEntry AS eme JOIN ExchangeMailboxStore AS ems ON ems.MbxStoreIdentity = eme.MbxStoreIdentity JOIN ExchangeServerEntry AS ese ON ems.ExchangeServerIdentity = ese.ExchangeServerIdentity WHERE eme.DefaultVaultId = ? |
Migrator server gets exchange quotas from exchange and sets them:
358 11:20:45.394 [5412] (MigratorServer) <7476> EV:L CMailboxHandler::GetEx2KUserQuotaValues (Entry) |
5359 11:20:45.394 [5412] (MigratorServer) <7476> EV:H CMailboxHandler::GetEx2KUserQuotaValues|Active Directory DN of the users mailbox: CN=Duck\, Donald,OU=Users,DC=contoso,DC=com|active directory distinguished name of the users message store:CN=Database01,CN=Databases,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=Contoso,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=contoso,DC=com|
5360 11:20:45.394 [5412] (MigratorServer) <7476> EV:H CMailboxHandler::GetEx2KUserQuotaValues|Binding using the following: GC://ServerDC01.contoso.com/CN=Duck\, Donald,OU=Users,DC=contoso,DC=com
5361 11:20:45.425 [328] (MigratorServer) <5932> EV:M CMailboxHandler::ProcessMessages (Exit) |Success [0] |
5362 11:20:45.425 [8436] (MigratorServer) <3516> EV:M CMailboxHandler::ProcessFolders (Exit) |
5363 11:20:45.425 [8704] (MigratorServer) <10912> EV:L CMailboxHandler::ProcessFolders (Entry) |
5364 11:20:45.441 [8704] (MigratorServer) <10912> EV:L CMailboxHandler::ProcessMessages (Entry) |
5365 11:20:45.441 [5588] (MigratorServer) <3512> EV:M CMailboxHandler::ProcessMessages (Exit) |Success [0] |
5366 11:20:45.519 [5412] (MigratorServer) <7476> EV:M CMailboxHandler::GetEx2KUserQuotaValues (Exit) |Success [0] |
5367 11:20:45.519 [5412] (MigratorServer) <7476> EV:M CMailboxHandler::OpenMailboxMsgStore (Exit) |Success [0] |
244291 11:23:25.213 [8436] (MigratorServer) <3516> EV:M CMailboxHandler::ProcessMessages (Exit) |Success [0] |
244292 11:23:25.213 [7508] (MigratorServer) <3364> EV:M CMailboxHandler::GetEx2KUserQuotaValues (Exit) |Success [0] |
244293 11:23:25.213 [7508] (MigratorServer) <3364> EV:L CMailboxHandler::SetEx2KUserQuotaValues (Entry) |
244294 11:23:25.213 [7508] (MigratorServer) <3364> EV:H CMailboxHandler::SetEx2KUserQuotaValues|Active Directory DN of the users mailbox: CN=Duck\, Donald,OU=Users,DC=contoso,DC=comactive directory distinguished name of the users message store:CN=Database01,CN=Databases,CN=Exchange Administrative Group (FYDIBOHF23SPDLT),CN=Administrative Groups,CN=Contoso,CN=Microsoft Exchange,CN=Services,CN=Configuration,DC=contoso,DC=com|
244295 11:23:25.213 [7508] (MigratorServer) <3364> EV:H CMailboxHandler::SetEx2KUserQuotaValues|Binding using the following: LDAP://ServerDC01.contoso.com/CN=Duck\, Donald,OU=Users,DC=contoso,DC=com
But no mention of what changes were made....