I am experiencing unusually high memory usage which is very concerning. I haven't been able to track down the cause or the solution. Can anyone help please?
Late 2009 27 inch iMac, 12 GB memory, Mavericks 10.9.5. Problem started earlier this year, seemed to resolve and is now alarming me. Currently only a few apps running. (Apple 2C in 1983 to 2014 MacBook Air and lots of Macs in between).
iMac, OS X Mavericks (10.9.5)
The one says Yosemite, but still should apply to Mavericks.
fsck_hfs, is the File System ChecKer (FSCK) for HFS/HFS+ file systems.
That fact that you have 6 of them visible either means you have 6 disk drives in need of being checked, or something is causing them to be started (maybe you are connecting/disconnecting to an external disk or network volume (such as Time Capsule, or a NAS), and the file system is in need of repair.
If you cannot figure out what disk (or disks) are in trouble, you could try in Activity Monitor, select one of the fsck_hfs processes, click on Activity Monitor -> View -> Inspect Process (or Command-I (as in the letter eye). Then click on the Open Files and Posts tab. Looking through the list of open files you should be able to find the device.
You could also try Applications -> Utilities -> Terminal
ps ax | grep fsck_hfs
and see what device is specified on the command line.
Translating the device to a volume might require using Applications -> Utilities -> Disk Utility and click on each volume listed and see what device Disk Utility says it is.
Whilst it's disconcerting to have several fsck processes using lots of RAM, it's not actually causing you to have memory issues.
See how the memory pressure graph is still green and there is no swapping happening (0 bytes of swap). The OS is using all available RAM, but that is not causing problems.
Memory pressure will go orange (when RAM compression is happening) and then red when swapping memory to disk. The red stage is where you want to be concerned, green & orange are normal.
This explains how RAM system changed in 10.9, it's worth a read if you want to get the general idea of the changes…
http://arstechnica.com/apple/2013/10/os-x-10-9/17/#compressed-memory
NOTE: fsck may also be checking a disk image for consistency in addition to a disk (some updaters mount dmg's in the background), see if the process completes. There might also be a log for Disk Utility in the ~/Library/Logs section of Console (inside /Applications/Utilities), or one for fsck_hfs. See if those indicate what disks or dmg's have been processed.
Thanks Eric, Bob and Drew. You have been a great help. With your assistance I seem to have been able to resolve the issues that have caused the really heavy memory usage.
You are welcome.
Very high memory usage
