Personal Computing

MacOS Catalina Stability?

MacOS Catalina is becoming increasingly colicky at Dismal Manor. Symptoms include kernel panics, application hard runs. User mail file corrupt or busy, etc. Most issues seem file system related. This post describes things we have tried to minimize issues.

Image is a screen capture of a screen capture from a blog article linked as Reference 2. Jim thought to catch this standard Apple alert box.

As Apple updates MacOS Catalina, stability appears to be on the decline. Here at Camp Dismal, we are experiencing a number of issues that the Dismal Wizard believed were related to USB disks. This 27 inch Retina iMac has 2, a USB Blue Ray drive from MacSales and a LaCie external disk that had been used for disk backup on our FreeNAS file server.

I’ve been sending crash reports to Apple. I can visualize some summer intern at home up to his armpits in panic reports and hang reports. What is going on? I have no effing idea. After the break, what I have tinkered with to no avail to remove the issue.


  1. Apple Support instructions to run Catalina hardware tests.
  2. for featured image credit.

The hardware is OK

I followed Apple Support’s instructions to run the hardware diagnostics. The hardware passed. These are a quick check similar to that in POST. The memory test patterns run are simple and only a pass or two are made. In the old days, we let the memory diagnostic run over night to provoke an error on a system having ECC memory.

This is a consumer Mac. It does not have memory parity checking let alone ECC which fixes single bit errors and logs most multi-bit errors. Leave the machine on long enough and it will have a soft memory error. Un-trapped soft memory errors can cause segment faults or illegal instruction errors in OS code or in user code.

Our network

Cox provides its mid-tier Internet service to Dismal Manner via the Hampton Roads cable plant and a Dismal Manor owned Netgear modem selected from the Cox approved list.

Our network uses Ubiquity UniFi kit including a Cloud Key 2+ for network management and garden video recording, a UniFi USG serving in the gateway router and firewall roles, a UniFi Switch 8-60 core switch in my study feeds two additional Switch 8-60 switches via a Switch 8-150 in the network closet. The Video switch serves the TV, related video gadgets (Tablo TV), and the FreeNAS server. The Audio Switch serves the HiFI and related audio gadgets. The core switch in my study serves this iMac, the printer, and related gadgets.

Our FreeNAS server is a home-brew Intel Xeon 1250 server having ECC and a 6x4TB Raid Z2 pool that serves as a Time Machine spool volume and media store for photos and video. This machine is also our Roon Server. Many of the gadgets mentioned above are Raspberry Pi Roon Endpoints running RoiPeee or HiFiBerry OS. More about them in another article. There is also an Apple TV 4 and a pair of EuFy Cam2 gateways in this gadget gaggle. The EuFy video cameras forward video to Apple iCloud storage. Apple TV and Apple HomePod devices provide this support. The Mac is not involved when the Home App is secured.

Diagram of the Notional Dismal Network

The Core Switch also connects and powers our two Unify In-wall WiFi access points and 3 UniFi video cameras.

Applications we use

  • MacOS mail and airmail 4
  • Roon
  • Apple Photos (iOS and MacOS)
  • Apple Safari and FireFox
  • Apple Work collection
  • IGGsoft Banktivity 7 for expense tracking
  • Apple Time Machine

Time Machine at Dismal Manor

We have Time Machine set up to back up only the iMac’s system disk. Time Machine is told to exclude the USB disk used for audio editing and the various FreeNAS shares. The FreeNAS system replicates the produciton pool to a second pool on an internal file-server grade 8TB disk. Since the active volume of the share is less than 4 TB, this arrangement has been fine.

FreeNAS at Dismal Manor

The FreeNAS host is an Intel Xeon 1250 built on a Supermicro workstation board using the C236 chip set. This chip set supports dual NICS and 8 Serial disk channels.

Future plans include the development of a second FreeNAS server on AMD hardware some time down the road. This new server will become the primary server and the current server will be come the replication server.

We take a daily snapshot that is replicated to the 8 TB disk. This policy catches most intentional changes and should give us a fall back checkpoint should ransom-ware slip by the rat guards. This is unlikey as most web browsing happens on an iPad to minimize this risk.

Recent Problems

This version of MacOS has exhibited very un-MacOS-like behavior such as.

  • Kernel panic while idle
  • Problems with Time Machine opening files on an AFP share served by FreeNAS.
  • Problems with USB external AFPS disk going to sleep and taking its sweet time to wake up.
  • Potential problems with USB Blue Ray Disk going to sleep and taking its sweet time to wake up.
  • Time Machine is active for the current logged in user. If the machine is logged off, no back-up happens. Current user owns the backup.
  • Each Time Machine user must have his own Time Machine Save Set.
  • OmniGraffle 7 did not like any pointing devices. OmniGraffle is now fired and replaced by Inkscape 1.0.

Recent Changes

  • Dismount and power off USB disks. The USB AFPS volume is used only for editing church service audio.
  • Create new SMBFS share for Time Machine use. This appears well behaved with FreeNAS 11.3. The fruity stuff currently works and enabling the FreeNAS data set Time Machine checkbox gets the attributes right.
  • Quit Mail or AirMail when finished reading mail. This appears to be a big help.

Lessons Learned

  1. Each user must have their own Time Machine data set on the Time Machine server. They are the Free BSD owner of this portion of the pool.
  2. Life is easier if FreeNAS and MacOS user names and user numbers match. For 1 or 2 users, it is not worth the effort of setting up an LDAP environment.
  3. FreeNAS SMB shares work well with MacOS Catalina Time Machine. The FreeNAS 11.3 Guide instructions for creating a Time Machine compatible data sheet work. FreeNAS versions prior to 11.3 may have difficulties speaking SMB with Time Machine.
  4. Stop Mail or AirMail when not actively in use. This gives a big improvement in mail stability and system stability. Both mail applications pole all mail accounts on startup so no benefit to letting them run.
  5. Dismount and power off idle external USB volumes. This avoids issues caused by USB drives going into hibernation to save energy.
  6. Check Time Machine last backup date. If Time Machine is active, leave the system up until Time Machine finishes. Otherwise, log the system out and put it to bed.

By davehamby

A modern Merlin, hell bent for glory, he shot the works and nothing worked.