Strace forked subprocess

How to attach strace to a forked process

Run this to see the forked process

strace -f ruby -e 'fork' 2>&1 | egrep -A1 '^(fork|clone)'

strace -f ruby -e 'syscall 57' 2>&1 | egrep -A1 '^(fork|clone)'

Run this to log debug of forked process in to log.txt

strace -f ruby -e 'fork' >log.txt 2>&1

strace -f ruby -e 'syscall 57' >log.txt 2>&1

Uroš

IBM Lotus NOTES Linux client 8.5.1 8.5.2 does not start

After unpacking Lotus Notes installation for the first run as user write file permission are required on file /opt/ibm/lotus/notes/framework/rcp/plugin_customization.ini

chmod 777 /opt/ibm/lotus/notes/framework/rcp/plugin_customization.ini

Uroš

Copy RPM packege configuration RED HAT

rpm -qa --queryformat "%{NAME} \n"|sort >remote-rpm-list.txt
rpm -qa --queryformat "%{NAME}\n"|sort >local-rpm-list.txt
diff -b remote-rpm-list.txt local-rpm-list.txt |grep "<" |awk '{print $2}' >install-rpm.txt
yum install `cat install-rpm.txt`

Oracle VM 2.2.0 Steps to enable PV drivers from one to max eight disks (hda-hdd and xvda-xvdd) for Oracle Linux 5.4

Problem IO driver crash

Identifiing virtual IO driver crash

dmesg messages

sym0: unexpected disconnect
sym0:1: No MSG IN phase after reselection.
sr 0:0:0:0: ABORT operation started.
sr 0:0:0:0: ABORT operation timed-out.
sr 0:0:0:0: DEVICE RESET operation started.
sr 0:0:0:0: DEVICE RESET operation timed-out.
sym0: SCSI BUS reset detected.
sr 0:0:0:0: BUS RESET operation complete.
sym0: SCSI BUS has been reset.
sym0:1: No MSG IN phase after reselection.
sr 0:0:0:0: ABORT operation started.
sr 0:0:0:0: ABORT operation timed-out.
sr 0:0:0:0: DEVICE RESET operation started.
sr 0:0:0:0: DEVICE RESET operation timed-out.
sr 0:0:0:0: BUS RESET operation started.
sym0: SCSI BUS reset detected.



Solution

1.
Change vm.cfg

use names hdx or xvdx at your convenience (xvdx devices should automatically use PV driver)

disk = ['phy:/dev/mpath/mpath10,xvdb,w!',
'phy:/dev/mpath/mpath11,hdb,w!',
'phy:/dev/mpath/mpath12,xvdc,w!',
'phy:/dev/mpath/mpath13,hda,w!',
'phy:/dev/mpath/mpath14,xvdd,w!',
'file:/var/ovs/mount/50B4E4F856D04A8991B741ABE6751EA2/iso_pool/OracleEL/Enterprise-R5-U4-Server-x86_64-dvd.iso,sda:cdrom,r',
]

2.
in /etc/modprobe.conf disable ata_piix and sym53c8xx virtualization drivers and enabled default xen PV driver xen-vbd

cat /etc/modprobe.conf

#alias scsi_hostadapter sym53c8xx
#alias scsi_hostadapter1 ata_piix
alias sym53c8xx off
alias scsi_hostadapter xen-vbd

2.1
You REAL shouldn't use virtual IO network driver

#alias eth0 8139cp #this driver is relay slow it defaults to ~36Mbit/s you should use netfront

3.
Create new initrd file with xen-vbd driver
mkinitrd -v initrd-2.6.18-164.el5.img 2.6.18-164.el5

4.
Change add following parameters to grub
ide0=noprobe noapic ide1=noprobe noapic
kernel /vmlinuz-2.6.18-164.el5 ro root=/dev/VolGroup00/LogVol00 ide0=noprobe noapic ide1=noprobe noapic rhgb quiet

5.
Chek if PV drivers are in use

find /sys/devices/xen/ |grep block

/sys/devices/xen/vbd-2048/block:sda
/sys/devices/xen/vbd-51760/block:xvdd
/sys/devices/xen/vbd-768/block:hda
/sys/devices/xen/vbd-51744/block:xvdc
/sys/devices/xen/vbd-832/block:hdb
/sys/devices/xen/vbd-51728/block:xvdb

6.
test performance with (performance should be very close to native)

hdparm -t /dev/xvdb


Regards
Uros