backupd 100% CPU

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Level 1

9 points

backupd 100% CPU

I am trying to backup my iMac to a Time Capsule. iMac is Late 2009 and connects over WiFi. Time Capsule is 4th Generation and hardwired to Verizon router providing WiFi.

Backups have always seemed slow, but now it seems much worse. The problem started after I was away and and the Time Capsule offline. Time Machine now needs to backup 126GB. From the logs, the backup was proceeding at about 20GB an hour which is reasonable. The last two hours it dropped to 2GB/hr and now 1GB/s and backupd is at 100%. Activity monitor shows periodic network I/O which might be from backupd. When it was running well, Activity Monitor showed pretty constant network output matching what was being reported in the Time Machine log.

I tried the recommendation

sudo sysctl debug.lowpri_throttle_enabled=0

when it was running at 20GB/hr.

I've also seen a lot of messages in the Time Machine log that complain about many files

Unexpected result from MDBackupIndexFile (1) for: <filename>

followed by

Error downloading promise cookie <filename>

When I check for the file, it is indeed missing. I don't have logs from when things were working better to know if the messages are new or just norma.

Any idea?

iPhone 4, iOS 4.3

Posted on Jun 2, 2018 5:47 PM

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Answer 1

Top-ranking reply

LaPastenague

Level 9

67,262 points

Jun 3, 2018 7:33 AM in response to hlev

Unless you have already got through most of the backup.. stop it .. It should take nowhere near that amount of time to backup. Nor should backupd be using 100% processor.

Pull the TC out of the network and plug it into the back of the iMac with ethernet patch cable.. and restart the backup.. I actually think you might be better wiping the TC and do a new backup completely but that is up to you. Once completed you can go back to wireless setup for incrementals.

What OS is the iMac running?

Sierra and later have lots of issues with backup to network targets.

I would encourage you to either..

1. Use the TC directly to the iMac via ethernet...permanently.. I can give further instructions so this works properly.

2. Even better and faster solution.. plug a suitably sized USB (FW800 also possible) into the iMac and use it for the TM target.. on Sierra it will be a lot more reliable.

3. Stop using TM for network backups post El Capo.. I recommend Carbon Copy Cloner as hugely superior. BUT your setup still might need ethernet. At least for first backup.

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Answer 2

Jun 3, 2018 2:35 PM in response to hlev

If I use the airport utility to configure an IP address on a new subnet and IP, and do the same on my iMac, that should be fine. No other device uses the TC for backups anymore. If I hose something on the TC configuration do you know if I can reset it back to DHCP without wiping out the TC drive contents.

This is indeed the method.

Here is some instructions to configure it.

Using Time Capsule hardwired to Mac for back-up only.

The trick is using internet over wireless.. so it must be the first network connection in the order listing. Ethernet will also need the correct gateway and DNS so as to not mess up the routing.

If you have issues just ask.

At the same time though.. direct backup to a USB drive is faster, much more reliable and in the end cheaper.. sell off the TC while it is still worth some money.

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Answer 3

hlev Author

Level 1

9 points

Jun 3, 2018 7:46 AM in response to LaPastenague

Thanks for the quick reply.

High Sierra.

This backup did finish overnight sometime.

I am running a verify on it now.

Read rates from over the network from the TC are 5-6MB/sec.

I was leaning towards direct connect ethernet too. TC is already ethernet only and connected to my router. I used to disable wifi on my iMac and just use an ethernet cable to my router since it is all nearby. At some point, something seemed to need access over wifi directly, which seemed odd, so I dropped the iMac ethernet connection and just use wifi for the imac now.

If I use the airport utility to configure an IP address on a new subnet and IP, and do the same on my iMac, that should be fine. No other device uses the TC for backups anymore. If I hose something on the TC configuration do you know if I can reset it back to DHCP without wiping out the TC drive contents.

A clean backup might make sense too.

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backupd 100% CPU

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