We have several machines on Amazon (ec2) of the type c1.xlarge with 8 cpus, running the Amazon AMI.
Details on the machine:
7 GB of memory
20 EC2 Compute Units (8 virtual cores with 2.5 EC2 Compute Units each)
1690 GB of instance storage
64-bit platform
I/O Performance: High
API name: c1.xlarge
One out of the several machines is showing a high load average, since we have run the last yum upgrade a couple of weeks a go. We did not yet update the other machines, and everything looks normal on them.
The strange thing is that the top command not showing any hint for the cause of the load. CPUs are -
4.8%us, 1.1%sy, 0.0%ni, 94.1%id, 0.0%wa, 0.0%hi, 0.0%si, 0.0%st.
Mem is about 1.5GB free.
Any idea what could it be, or where else can we check?
iostat command on the proper machine:
avg-cpu: %user %nice %system %iowait %steal %idle
8.97 0.03 4.46 0.19 0.14 86.23
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
xvdap1 1.60 0.69 55.38 587620 47254184
xvdfp2 2.64 1.10 61.04 934786 52091056
xvdfp4 0.86 0.19 41.72 163866 35601920
xvdfp1 4.37 36.59 73.89 31220810 63051504
xvdfp3 8.03 7.08 94.63 6045402 80749184
iostat command on problematic machine:
avg-cpu: %user %nice %system %iowait %steal %idle
9.29 0.04 5.55 0.26 0.11 84.74
Device: tps Blk_read/s Blk_wrtn/s Blk_read Blk_wrtn
xvdap1 2.13 3.34 68.85 246244 5077888
xvdfp1 7.60 74.31 104.88 5480362 7734840
xvdfp3 13.22 73.67 125.00 5433386 9218600
xvdfp4 1.11 0.76 65.08 55762 4799248
xvdfp2 4.16 3.31 99.17 243818 7313264
Many thanks for the help.
