What's causing all that disk I/O on my Mac?
21 May 2012
After doing a full re-install of my MacBook Pro a few weeks back to combat system slowness, I’m again struck with a slow system.
The problem is that there’s a lot of disk I/O going on. CPU and memory are fine. I’m just not sure what’s causing this trouble.
Luckily, there’s an easy solution to find out what’s doing disk I/O on you mac.
Open up a terminal and run
$ sudo fs_usage 09:08:45.749208 read F=12 B=0x400 0.000210 W Sparrow.3845544 09:08:45.749274 lseek F=12 O=0x0602e000 <UNKNOWN> 0.000002 Sparrow.3845544 09:08:45.749279 read F=12 B=0x400 0.000005 Sparrow.3845544 09:08:45.749341 lseek F=12 O=0x06038c00 <UNKNOWN> 0.000002 Sparrow.3845544 09:08:45.750358 RdData[async] D=0x025aaf38 B=0x1000 /dev/disk0s2 0.028830 W Sparrow.3845547 09:08:45.750379 pread F=16 B=0x30 O=0x00b32730 0.028895 W Sparrow.3845547 09:08:45.750390 pread F=16 B=0x30 O=0x0de9a810 0.000008 Sparrow.3845547 09:08:45.750396 pread F=16 B=0x30 O=0x1f5ec5c0 0.000006 W Sparrow.3845547 09:08:45.750399 pread F=16 B=0x30 O=0x236c84a0 0.000003 Sparrow.3845547 09:08:45.750405 pread F=16 B=0x4b O=0x236c84b6 0.000002 Sparrow.3845547 09:08:45.750701 pread F=16 B=0x30 O=0x00c95f00 0.000007 Sparrow.3845547 09:08:45.758502 RdData[async] D=0x04f0b608 B=0x1000 /dev/disk0s2 0.009148 W
What you see here is Sparrow doing mad reads ot my disk. I’m not sure what it’s doing, but it must stop. After killing Sparrow disk I/O goes down to normal, workable levels again.
Now, to pick another mail client for Mac…