100% disk utilization on /boot partition!!

locus84 · 08-24-2011, 04:59 PM

I noticed that there was a lag on this linux machine, but the load is pretty low. There is plenty of memory and idle cpu, but look at the iostat results:

Code:

Device: rrqm/s wrqm/s rsec/s  wsec/s rkB/s wkB/s avgrq-sz avgqu-sz await svctm  %util
hda       0.00   0.00   0.00    0.00  0.00  0.00     0.00     0.00  0.00  0.00   0.00
hda1      0.00   0.00   0.00    0.00  0.00  0.00     0.00     1.00  0.00  0.00 100.05
hda2      0.00   0.00   0.00    0.00  0.00  0.00     0.00     0.00  0.00  0.00   0.00
dm-0      0.00   0.00   0.00    0.00  0.00  0.00     0.00     0.00  0.00  0.00   0.00
dm-1      0.00   0.00   0.00    0.00  0.00  0.00     0.00     0.00  0.00  0.00   0.00

Here's the 'df -h' result:

Code:

Filesystem                        Size  Used Avail Use%  Mounted on
/dev/mapper/VolGroup00-LogVol00   457G   62G  372G  15%  /
/dev/hda1                          99M   32M   62M  35%  /boot
none                              7.9G    0   7.9G   0%  /dev/shm

and Here's the top result:

Code:

load average: 0.22, 0.25, 0.19
Tasks: 380 total,   1 running, 378 sleeping,   0 stopped,   1 zombie
Cpu0  :  0.0% us,  0.3% sy,  0.0% ni, 99.7% id,  0.0% wa,  0.0% hi,  0.0% si
Cpu1  :  0.3% us,  0.3% sy,  0.0% ni, 98.0% id,  1.0% wa,  0.0% hi,  0.3% si
Cpu2  :  0.0% us,  0.0% sy,  0.0% ni, 99.7% id,  0.0% wa,  0.0% hi,  0.3% si
Cpu3  :  1.0% us,  0.3% sy,  0.0% ni, 98.7% id,  0.0% wa,  0.0% hi,  0.0% si
Mem:  16437828k total, 12905212k used,  3532616k free,   117612k buffers
Swap: 10420208k total,        0k used, 10420208k free,  9830312k cached

running 'lsof /boot' returns nothing. any idea what's causing this, might it be that the disk has bad sectors?

business_kid · 08-25-2011, 11:52 AM

Your statement in the title appears wrong.

Quote:

/dev/hda1 (size)99M (used)32M (free)62M 35% /boot

leave it alone.Explain what is lagging.

locus84 · 08-25-2011, 05:38 PM

The statement is not wrong, maybe incomplete; the disk IO utilization, as indicated by the iostat output is indeed 100%, though the disk space usage is 35%.

business_kid · 08-26-2011, 03:10 AM

Okay. You don't actually _need_ /boot mounted as it's a separate partition. Comment it out of /etc/fstab, or better, put the word noauto in as an option. You can mount it when you want to fiddle with grub, or kernels.

Explain what is lagging: Disk i/o, everything? Do run top and see what's grabbing power