quicklookd and revisiond eating my CPU

I'm observing regular and abnormal CPU usage on my macbook pro. quicklookd in par with revisiond are eating together over of 50%. It drains my battery significantly and makes the whole machine hot. I'm not sure when exactly it started but I'm suspecting latest 10.10.3 upgrade as I didn't notice this before. After reading some post on the net I cleared ~Libraries/Cache and /private/var/folders then rebooted. It looked like the problem was gone (those processes didn't show up), but only for a while. The next day I resumed from sleep, again - quicklookd and revisiond started to burn my CPU. Any clues how to get rid of this? What's causing this problem? It looks like these two processes are somehow connected, because when I cleared the cache and restarted none of them used a lot of cpu. Today, both of them do (quicklookd 24-30% , revisiond ~15%). **[Update]** Running sudo opensnoop -n revisiond shows nothing. Running sudo opensnoop -n quicklookd brings endless list of entries like these: UID PID COMM FD PATH 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 21 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / 501 4783 quicklookd 23 / It goes on and on and on. It's just endless. FD column is always 23 except two or three 21. **[Update 2]** After few minutes I got some other entries besides 501 4783 quicklookd 23 / (not pasting theme here as they were irrelevant) And then again, whole lot of 501 4967 quicklookd 23 / **[Update 3]** I've also noticed that diskarbitrationd and diskmanagementd scores quite high (~ 5%) and stay on top of the process list (sorted by CPU usage) just below quicklookd and revisiond. Looks like this also might have something to do with this issue. I've closed (cmd + q all other apps to make sure nothing interferes the measurements). **[Update 4]** Found few interesting entries in console: Failed to obtain sandbox extension for path=/Users/me/Library/Caches/com.apple.quicklook.satellite. Errno:1 CGSConnectionByID: 0 is not a valid connection ID. [QL] Using too much memory (161 MB), hit critical threshold (120 MB), exiting immediately to clean up. [QL] Unable to write memory cache on disk In -[NSApplication(NSQuietSafeQuit) _updateCanQuitQuietlyAndSafely], _LSSetApplicationInformationItem(NSCanQuitQuietlyAndSafely) returned error -50 They repeat few regularly each day. Especially those about memory and invalid connection. **[Update 5]** sudo iosnoop -n quicklookd revealed this: UID PID D BLOCK SIZE COMM PATHNAME 501 5656 W 56385320 32768 quicklookd ??/Quick Look/cloudthumbnails.db-journal 501 5656 W 56385320 4096 quicklookd ??/Quick Look/cloudthumbnails.db-journal 501 5656 W 48100696 12288 quicklookd ??/Quick Look/cloudthumbnails.db 501 5656 W 48100816 8192 quicklookd ??/Quick Look/cloudthumbnails.db 501 5656 W 48100840 8192 quicklookd ??/Quick Look/cloudthumbnails.db 501 5656 W 56385640 28672 quicklookd ??/T/etilqs_kYNR5XinU71bydh 501 5656 W 56386736 32768 quicklookd ??/Quick Look/cloudthumbnails.db-journal 501 5656 W 56386736 4096 quicklookd ??/Quick Look/cloudthumbnails.db-journal 501 5656 W 48100696 12288 quicklookd ??/Quick Look/cloudthumbnails.db 501 5656 W 48100816 8192 quicklookd ??/Quick Look/cloudthumbnails.db 501 5656 W 48100840 8192 quicklookd ??/Quick Look/cloudthumbnails.db 501 5656 W 56387280 28672 quicklookd ??/T/etilqs_ejadCww3DunYuu3 cloudthumbnails.db and cloudthumbnails.db-journal repeats and repeats.