Time Capsule is slow

Question

Hi there,
I have been using my Time Capsule for around 6 months now - both on my MacBook Pro and iMac (Leopard 10.5.5). I am experiencing troubles when I try to backup. Basically, Time Machine just stalls on the "Preparing Backup..." status. I haven't been able to successfully backup in about a week now.
Has anyone got some solutions to this problem?
Thanks in advance,
Ricky.

Answer 1

ricky,
Here are some thoughts that might give you some ideas on troubleshooting this:
*_Time Machine May Report "Preparing..." For a Long Time_*
First, it’s good to determine WHY Time Machine is "Preparing..." for an extended period of time. Examining the Console logs during this event can reveal what is actually going on behind the scenes. It may be “Preparing…” for a genuinely good reason. How long is 'too long' to wait for Time Machine to finish "Preparing..."? Some times, "Preparing..." is required to perform the normal housekeeping that Time Machine does periodically. Other times, it really is "stuck" and never proceeds after more than 24 hours.
*”Deep Traversal” (Recent Crash / System Update / Extended Period Between Backups)*
According to the following KB article it can sometimes take quite a long time if Time Machine begins a “deep traversal” and has to compare data inventories. This may apply to your situation, particularly if many Gigs of data are involved. [http://support.apple.com/kb/TS1516]
You see, Time Machine *+does not+* ordinarily perform file-by-file comparisons to determine what has changed and thus determine what needs to be backed up. Rather, Time Machine relies on FSEvents notifications. This is a log that the system uses to keep track of changes to directories. Rather than scan tens of thousands of files for changes each time, Time Machine simply looks at this log and narrows its’ scan to only the directories that have experienced changes since the last backup. Otherwise, Time Machine would have to be running constantly just to catch every change on its own and thus eat up precious CPU.
If the system crashes, experiences a power failure, or some other major system event, then Time Machine will consider the FSEvents log as “untrustable”. In this event, Time Machine will by-pass the system log and perform its’ own file-by-file comparison to determine what has changed since its’ last backup. This is called a “deep traversal”. Obviously, if tens or hundreds of Gigs are involved, then this process can take quite some time and should be allowed to proceed.
Every event that FSEvents records has its’ own ID which includes a time stamp. At the end of every backup, Time Machine stores the last event ID that it processes. When the next backup is initiated, Time Machine looks at this stored ID and determines that it only needs to backup events that have occurred after the time stamp on this last event ID. If, for some reason, Time Machine cannot find this last event ID in the system logs then it will consider the logs “untrustable” and it will go into “deep traversal”.
Additionally, it appears that if Time Machine has to go back too far to find the last event ID, then it will give up and simply go into “deep traversal” and do the file-by-file scan on its’ own. This can occur if Time Machine has not been able to perform its’ hourly backups for some time, as is the case for users who only backup once a week or so.
*Anti-Virus Software*
Running anti-virus software can interfere with the backup process. Either disable it altogether, or try the suggestion outlined here, “If you use third-party anti-virus scanning software and have issues, make sure your Time Machine back up folder (Backups.backupdb on the Time Machine disk) is excluded from virus scanning.” (http://support.apple.com/kb/TS1516)
*Software Updates* #
Installing new software, upgrading existing software, or updating Mac OS X system software can create major changes in the structure of your Macs directories. Time Machine will backup every file that has changed since the installation.
After an OS update (like 10.5.5) Time Machine realizes the system no longer matches what it looked like during the previous backup. So it has determined that it's earlier catalogue of what-should-be-where is “untrustable”. So it is going to go item-by-item comparing the before and after of your system. If you have just performed an OS Update then Time Machine knows what it's doing - let it do it!
*Spotlight Keeps Indexing Backup Drive* #
It may be that Time Machine can’t proceed or complete a backup due to a Spotlight indexing error. During this period, take a look at the Spotlight icon in the upper right corner of your screen. Is there a tiny dot pulsating in the center of the spyglass? Click on the icon. Is there a progress bar displayed? Generally, Spotlight indexing is a good thing. If it has only been a couple of hours then let the process continue.
However, at times it may hang and never progress after many hours, preventing further backups from taking place.
Go to System Prefs --> Spotlight --> Privacy Tab.
Drag your Time Machine disk into the window. It should now be among the items to exclude from indexing.
Now quit System Prefs.
Reboot your Mac.
Reopen System Prefs and remove ("-") the Time Machine disk from the window.
Now initiate a backup.
This should clear out Spotlights cache. Naturally, Spotlight should begin indexing again (maybe even for a few hours depending on how much data there is), but it should eventually stop.
*Run Away System Process*
It’s possible that Time Machine is stuck “Preparing…” because another process is monopolizing your Macs’ CPU. Launch Activity Monitor and sort the items by “CPU”. Is there a process that is at or near 100% that might be preventing the backupd process from moving forward?
One poster stated, “I took it to my local Genius Bar and they found a Syslogd daemon running, taking up 100% of my CPU. The result (other than bad performance) was that the disk configuration was constantly dynamic, thus TM could never pin it down to back it up. This resulted in the "Preparing..." mode running forever. They resolved it by simply reloading the OS X to 10.5.4. It ran fine on that and I've now updated back to 10.5.5 and everything is running fine.” [http://discussions.apple.com/thread.jspa?threadID=1755600&tstart=15]
You can use Activity Monitor to “kill” the offending process. Or you may be able to resolve it simply by rebooting your Mac. Then try backing up again.
*Reboot Time Capsule* #
If, though, none of the options above have helped and it has been 12 hours or more of “Preparing…”, then the Time Capsule may need to be restarted.
Stop the backup from the Time Machine menu. (Give if a few minutes while it says “Stopping backup…”)
When the Time Machine icon stops spinning, unplug the TC from the wall outlet.
Wait 10-15 seconds.
Re-plug it in again.
After it has restarted (30-60 seconds), attempt another backup.
Time Machine will report “Preparing…” again, but it shouldn’t be lasting more than a couple of hours.
Let us know if any of the above was helpful in your case.
Cheer!