How to diagnose high storage I/O

[zyberwoof]

I have noticed that my phone gets so slow it is practically unresponsive often. I strongly believe that the culprit is high I/O. Using an app I can often show that the storage is at or near 100% utilized when my phone gets slow. Sometimes it is from high reads (around 12-15 MB/s), and others it is maxing out on writes (around 3-4 MB/s). At this same time, my utility shows that my CPU usage is usually well below 50%.

My phone is running MoKee 4.4.2, but I have had the same issue with CM running ICS and Jelly Bean.

My questions are
#1 Is there any way to monitor what apps are reading and writing to storage? My device is rooted, and I use Linux on my desktop if that helps.
#2 Do you know of any common culprits for this issue?
#3 Any other ideas?

 

[Mooncatt]

My phone is running MoKee 4.4.2, but I have had the same issue with CM running ICS and Jelly Bean.

So this issue is on the same phone that started out on ICS? If so, my guess is the phone is fairly old, with limited Ram by today's standards. Have you looked into your Ram utilization? While it's generally a good thing for Android to use as much Ram as possible, I had similar problems with my last phone over time. It would get sluggish and non-responsive, and I think the likely culprit is there was more apps requesting Ram in the background than there was memory available. So the OS was constantly busy killing and restarting apps, which bogged down the over all performance of the phone.

 

[zyberwoof]

Sometimes it happens when only a few apps appear to be open. I am judging this by what I get when I hold the Home button for a second and get the list of running apps, which may not be accurate.

Whenever I check, my RAM usage looks to be around 75%. But RAM is a tricky thing since unused RAM is wasted RAM. I just checked my phone and it was at 79% usage. I cleared all open apps by holding Home for a second, and them swiping off all of the apps in the list. The RAM utilization only went down to 70%.

I have a Motorola Droid Bionic. It has 1 GiB of RAM (although my phone only shows 840 MB available), it is a 2.5 year old model, and it started with Gingerbread when it first came out. I figure 1 GiB should be considered fine by today's standards.

Thanks for the suggestion. It is a good thought that it might be swapping apps in the background. That would eat up I/O.

P.S. My RAM utilization went back up to 79% while typing this, even without opening any new apps.

 

[Mooncatt]

My last phone was that Bionic too, so I'm in familiar territory. Lol. Yes, my guess is it's running too low on Ram. Holding down the home key and swiping away apps doesn't necessarily close them out right away, nor does it list background apps that are running without active notifications. Even if you were to go into the app manager and manually force stop apps, many are programmed to restart. I couldn't really find away around it without doing a lot of extra work freezing and thawing apps as needed. Rebooting helps clear a lot of the data apps are using (more so than clearing cache it seemed), but that was only a temporary fix as they would build more data in Ram over the next few days.

Hate to say it, sounds like you'll either need to uninstall some things, or get a newer phone with more Ram.

 

[Mooncatt]

Btw, what are you using to monitor I/I speeds?

 

[zyberwoof]

I'm using an app called "System Monitor". It shows the overall disc I/O, but it doesn't break it down by app.

 

[Mooncatt]

Thanks, I may check it out just for my own curiosity.