Can retrospect engine cause a kernel task peak and hold a 100% ?

[oslomike]

It seems that when I start the Retrospect application (most recent version), and subsequent Retrospect engine, I notice that after about 30seconds, I get a kernel task appear in the activity monitor that that shows a usage of 100%+. Side effects are that I lose communication to the LTO tape drive and all ethernet connections seem frozen, both internet (ethernet to switch for LAN and internet) and iSCSI SAN storage on the second ethernet port. I'm trying to figure out what's causing this because it stops any possibility of backing up to the LTO and also accessing the data on the SAN. I'm running the program on a 5,1 Mac Pro running High Sierra. Other than Retrospect, I only have the ATTO SAS driver and the StudioNetworkSolutions initiator and SAN client software installed on this machine; it's basically a new install with only what's needed to run backups. 

Has anyone ever heard of these symptoms?

[DavidHertzberg]

oslomike,

Has this ever worked?  If so, what's changed?  (My Mac Pro (5,1) boots Sierra and runs Retrospect 16.6 to backup to portable HDDs; I have no SAN.)

How is your LTO tape drive connected to your Mac Pro (5,1)?   If it's a SAS-attached drive, the Retrospect Storage Devices lookup widget shows a number of approved tape drives.  However if it's an iSCSI-attached drive, the same lookup widget shows no approved drives.  That might explain why this kernel task is appearing on you Mac Pro (5,1).  Since you're in Norway, I suggest checking with Retrospect European Tech Support.  They'll probably forward your question to Worldwide T. S. in Walnut Creek CA.

Also, I just did a Google search on "Storage Network Solutions tape" (without the quotation marks).  It revealed that SNS also sells expensive LTO archiving hardware.  Possibly the software intended for that hardware is being activated by Retrospect Engine use of LTO—especially if via iSCSI?

As I suggested in your other recent thread,  why don't you attach the tape drive from your  "dinosaur machine ... that is soon 20 years old" to your Mac Pro (5,1)?  Since the Mac Pro (5,1) has 4 PCI card slots, you could probably move over the SCSI card from that "dinosaur" if it is needed to run the old tape drive.  If it's not an ATTO card—needed to run SCSI on macOS later than 10.3, you can buy one for US$40 on eBay.

Finally, all Retrospect Mac "backup server" Engines since ver.8 start—if On—at macOS boot.  Starting "Retrospect"  just does a  Console-Engine sync.

Edited December 29, 2020 by DavidHertzberg
Add third through fifth paragraphs. Add info about my "backup server" to first paragraph.

[Nigel Smith]

It's probably comms with the tape drive that are causing the problem, but make sure by disabling the iSCSI initiator, turning off the drive, turning off the RS Engine auto-start, rebooting the Mac, waiting 5 minutes (for log messaging to settle), manually starting the RS Engine and then launching console. (Manually starting the Engine gives you a known time-point for you to check the system logs.)

If all is good, do the same but this time with the iSCSI initiator enabled. Then the same but with the tape drive turned on.

I'm betting it'll reproduce the problem in the last test. As David suggests, you should try again with the drive on but the iSCSI initiator disabled, just to be sure there's no clash there.

Then we're on to details -- SAS card, tape drive type, make sure card and drive firmware are correct for your OS and Retrospect, re-seat the SAS card, try a different cable, etc.

[oslomike]

I did a little more research and it seems that the key is to NOT have the Retrospect Engine in Auto Start mode when booting the Mac. I don't know what happens, but when I boot the back without the Retrospect Engine starting automatically, and then start it after the computer has fully booted, then communication works as normal, no problems with drivers, cards, iscsi or any communication. Just smooth. The ATTO SCSI and SAS cards are a bit older so I had to turn off SIP in order to install the drivers, so that may also have something to do with it as well. BUT for now, it's working and I feel confident I know how to keep it running like this. If makes you think of anything else I should look into to make the system even more stable, please let me know. Thanks!!