[Users] May 25, 2021 Zeta Alliance Conference Call Summary

[Randy Leiker]

Hello Zeta Alliance Community, 

Here is a summary of this week’s conference call. A few brief reminders: 


    * Conference calls are every Tuesday and open to all using either the FreeConferenceCall.com VoIP app or via a dial-in number: [ https://www.freeconferencecall.com/wall/zetalliance | https://www.freeconferencecall.com/wall/zetalliance ] 
    * Each week’s call agenda can be found at: [ https://drive.google.com/drive/folders/1xDyBJFjnfZYxuXJHiDzsXjjMuGGtIl7J | https://drive.google.com/drive/folders/1xDyBJFjnfZYxuXJHiDzsXjjMuGGtIl7J ] 
    * A copy of each week’s summary is also posted to the Zimbra Forums: 
        * All Prior Months: [ https://forums.zimbra.org/viewforum.php?f=9 | https://forums.zimbra.org/viewforum.php?f=9 ] 
        * April 2021 : [ https://forums.zimbra.org/viewtopic.php?f=9&t=69507 | https://forums.zimbra.org/viewtopic.php?f=9&t=69507 ] 
        * May 2021 : [ https://forums.zimbra.org/viewtopic.php?f=9&t=69570 | https://forums.zimbra.org/viewtopic.php?f=9&t=69570 ] 
    * Constructive feedback on these call summaries is always welcome. 

May 25 , 2021 

Upcoming 8.8.15 Patch 22 and 9.0 Patch 15 
Mark S. asked if the upcoming 8.8.15 Patch 22 and 9.0 Patch 15 will include the Zextras 3.1.11 version ( [ https://docs.zextras.com/zextras-suite-documentation/latest/home.html | https://docs.zextras.com/zextras-suite-documentation/latest/home.html ] ). John H. said this is unlikely as the 3.1.11 version just started regression testing at Zimbra, so if all of the tests pass, it will likely instead be included within 8.8.15 P23 and 9.0 P16. 

Suggestions For Frequency of Blob Checks and Backup Coherency Checks 
Randy L. said that he is re-visiting his policies for how frequently blob checks (zxsuite hsm doCheckBlobs) and backup coherency checks (zxsuite backup doCoherencyCheck) are performed to proactively address blob or backup integrity issues on his Zimbra servers. He asked everyone on the call for their thoughts as to if they proactively run these checks as well, or reactively perform these checks when a problem is reported by a SmartScan or by a mailbox owner. Mark S. said that when he was first getting started with the Centralized Storage feature ( [ https://zimbra.github.io/zimbra-9/adminguide.html#centralized-storage | https://zimbra.github.io/zimbra-9/adminguide.html#centralized-storage ] ), there was a bug, that has since been fixed in a Zimbra patch, that would routinely indicate a problem with his mailbox backups, so he was frequently running backup coherency checks at that time. Since then, he normally does not run coherency checks unless alerted to a problem by either the daily or real-time SmartScans, as he feels the SmartScans perform an adequate incremental coherency check of backups. Mark added that when he moves mailboxes, he does occasionally experience issues with orphaned blobs that are not deleted for some reason, so those do need occasional clean-up with a blob check. Noah P. said that he does not normally run recurring backup coherency scans, but a proactive scan has recently uncovered quite a few inconsistencies in the backups. He suspects these might be due to bugs in earlier versions of Zimbra/Zextras mailbox tools, as he does a large number of mailbox moves in his Zimbra environment. He has not yet decided if he will continue running these checks regularly once all of the issues are fixed. He added that he finds the Zextras tools do a good job of consistently cleaning up problems, as compared to earlier deprecated utilities like zmblobchk. Mark S. said that in an instance where the current Zimbra backups are suspect, a strategy that can be used to get known good backups by the current Zimbra/Zextras version is to unmount the disk containing the current backups, then mount a new blank backup disk, and run a full backup. Both disks can then be maintained for a period of time until the unmounted disk, containing the earlier backups, ages out and can be deleted. Randy L. agreed that this is a good strategy when the backups are untrusted, but said that he was looking at it more from the perspective of ongoing proactive maintenance of blobs and backups, as compared to a one-time fix for backups with known issues. 

Zimbra Desktop Beta 
Following up on the April 13th Zeta Alliance call, John E. said the Zimbra Desktop beta is ongoing and offered that if anyone would like to join in on the beta testing, to reach out to him. Mark S. asked if the beta version self-updates? John E. said he does not think so, and was surprised to learn that it does not self-deactivate after the beta period ends either. Mark S. asked if the Zimbra Desktop beta is available somewhere for download? John E. said that it is by invitation only, so it is not on a public web site for download, and reiterated that it is currently beta-quality software at present. 

Follow-Up: Using doMailboxMove To Pre-Stage Mailbox Blobs 
Following-up on the May 11th Zeta Alliance call, Randy L. shared an update on David M’s experiences with using the “stages” parameter for mailbox moves (zxsuite hsm doMailboxMove stages) between geographically dispersed data centers. Randy said that he was discussing this topic in more depth with David in a separate conversation recently and David said that he has been able to successfully move mailboxes in two steps: by using the “stages blobs” parameter to move mailbox blobs first, followed by moving mailbox metadata (“stages account”). Previously, David had been attempting to move each mailbox in a single step, but found that moved mailboxes were experiencing issues where the Zimbra Web Client would fail to render all page objects, or moved mailboxes configured to use Outlook were reporting client-side time-out related errors. Matthew F. asked if David had opted to move his backups (“stages backup”) with the mailbox moves or not. Randy said he did not know, since David was unavailable on today’s Zeta Alliance call to comment. Matthew said that he has a Zimbra cluster spread across 4 geographically dispersed data centers, and has not observed client-side issues when performing mailbox moves, but added that he does not normally move backups with the mailboxes. Matthew said that he did make one tweak to Nginx in Zimbra to disable its default time out checks for mailbox servers (zimbraMailProxyReconnectTimeout and zimbraMailProxyMaxFails), as this has caused issues in the past where Nginx would incorrectly flag a mailbox server as being unavailable. Randy said that he thinks David said something earlier about disabling the Nginx mailbox server time out check too, but was not sure. In David’s case, he found success with changing the address that Memcached binds with on the proxy servers at both of his data center locations ("zmprov ms $(zmhostname) zimbraMemcachedBindAddress 127.0.0.1" and "zmprov ms $(zmhostname) zimbraMemcachedClientServerList 127.0.0.1" and "zmmemcachedctl restart"). 


Randy Leiker ( randy at skywaynetworks.com ) 
Skyway Networks, LLC 

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