macOS Big Sur Known Issues

Product: 
ccc5

Some Big Sur startup volumes don't appear in the Startup Disk Preference Pane

In the past, the Startup Disk Preference Pane would list all available startup volumes, including volumes cloned by CCC (whether CCC used ASR or its own file copier). Some Big Sur cloned volumes do not appear in the Startup Disk Preference Pane, despite being perfectly bootable.

We have reported this issue to Apple (FB8889774) and we are currently awaiting a response.

Résoudre les problèmes de réplication APFS

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ccc5

L'utilitaire de réplication APFS d'Apple fonctionne généralement rapidement et sans souci, mais il gère mal (voire pas du tout) certaines situations spécifiques. CCC s'efforce d'éviter le plus possible ces résultats problématiques. Néanmoins, voici quelques conseils en cas d'échec avec l'utilitaire de réplication APFS d'Apple.

Some third-party storage drivers may cause hardware misbehavior

Product: 
ccc5

We occasionally receive reports of strange behavior from USB devices, e.g. slow performance, disks dropping offline in the middle of the backup task. In some of those cases we've discovered that third-party storage drivers are causing the problem. In particular, the SAT-SMART drivers and some ancient BlackBerry USB drivers can lead to problems. If you're troubleshooting a USB device behavior or performance problem, we recommend that you consider uninstalling these drivers.

macOS Catalina Known Issues

Product: 
ccc5

Apple introduced a bug in 10.15.5 that prevents the creation of firmlinks

The chflags system call no longer works correctly on 10.15.5 with regard to setting the special "firmlink" flag that establishes links betweent the System and Data volume group members. If you're establishing a new backup of macOS 10.15.5 or later, CCC 5.1.17 (and earlier) will be unable to create a correctly-functioning APFS volume group. Many folders on the destination volume will appear empty, and the volume will not be bootable.

Why does Finder prevent me from viewing the home folder on my backup when it's attached to another Mac?

Product: 
ccc5

Update November 2020: Apple has resolved this Finder bug in macOS Big Sur.

"The task was aborted because a subtask did not complete in a reasonable amount of time"

Product: 
ccc5

Occasionally a backup task can stall if the source or destination stops responding. To avoid waiting indefinitely for a filesystem to start responding again, Carbon Copy Cloner has a "watchdog" mechanism that it uses to determine if its file copying utility has encountered such a stall. By default, CCC imposes a ten minute timeout on this utility. If ten minutes pass without hearing from the file copying utility, CCC will collect some diagnostics information, then stop the backup task. Our support team can analyze this diagnostic information to determine what led to the stall.

CCC signale que la destination est saturée. Comment éviter cette situation ?

Product: 
ccc5

Par défaut, CCC utilise au départ un seuil d’élagage SafetyNet qui exige 25 Go d’espace disponible sur la destination au début de chaque tâche de sauvegarde. CCC augmente ce seuil automatiquement lorsque c’est nécessaire. Si vous n’utilisez pas les réglages SafetyNet par défaut de CCC et qu’un message d’erreur indiquant que la destination est saturée s’affiche, vous pouvez définir un seuil d’élagage moins strict dans les réglages avancés. La quantité d’espace libre nécessaire sur la destination dépend de la taille des fichiers modifiés en temps normal, pendant la journée par exemple.

Troubleshooting slow performance when copying files to or from a network volume

Product: 
ccc5

Network performance is usually the bottleneck of a backup task that copies files to or from a network volume, but there are several other factors that can affect performance as well. Here are some suggestions for improving the performance of your NAS-based backups.

CCC recopie tous les fichiers à chaque sauvegarde. Pourquoi ?

Product: 
ccc5

CCC copie uniquement les éléments qui sont différents sur la source et la destination. Donc, si vous effectuez une tâche de sauvegarde que vous exécutez à nouveau le lendemain, CCC ne copie que les éléments ayant été créés ou modifiés depuis la dernière tâche de sauvegarde. CCC détermine si un fichier est différent à l’aide de sa taille et de sa date de modification. Si la taille ou la date de modification du fichier présente la moindre différence sur la source et la destination, CCC copie le fichier sur la destination.

Why can't I eject the destination volume after the backup task has completed?

Product: 
ccc5

The disk Backup wasn't ejected because one or more programs may be using it.

Occasionally this annoying message comes up when you're trying to eject your destination volume. If CCC is currently using that volume as a source or destination to a running backup task, then CCC will effectively prevent the volume from being unmounted gracefully. If your backup task isn't running, though, CCC isn't preventing the volume from being unmounted. But what application is?