lsof Senario

/ root is out of space 😉

[root@ ~]# df -kh
Filesystem            Size  Used Avail Use% Mounted on
<strong>/dev/sda3              78G   68G  6.5G  92% /</strong>
/dev/sda6             9.9G  155M  9.2G   2% /tmp
/dev/sda2             152G   16G  128G  11% /u01
/dev/sda1              99M   12M   83M  13% /boot
tmpfs                  16G  9.5G  6.3G  61% /dev/shm
/dev/mapper/backupp1  296G   66G  215G  24% /backup
/dev/mapper/mpath1    197G   85G  103G  46% /bkup-new

Below is the file which is deleted but space still showing utilized on  DB2.

tcpdump   23514      pcap    4w      REG                8,3 69948653568              7643527 /var/tmp/pcap/barsha-db2-17Jan_17_00.pcap (deleted)

Always run command lsof -l | grep deleted

Then kill the process id.

[root@~]# df -lkh
Filesystem            Size  Used Avail Use% Mounted on
/dev/sda3              78G  8.4G   66G  12% /
/dev/sda6             9.9G  155M  9.2G   2% /tmp
/dev/sda2             152G   16G  129G  11% /u01
/dev/sda1              99M   12M   83M  13% /boot
tmpfs                  16G  9.5G  6.3G  61% /dev/shm
/dev/mapper/backupp1  296G   66G  215G  24% /backup
/dev/mapper/mpath1    197G  103G   85G  55% /bkup-new

It is now deleted, 🙂

Red Hat / Oracle Enterprise Linux I/O tuning for Oracle databases

Starting with Red Hat 4 you can choose between four I/O scheduler which have all their pros and cons versus what you run on your server:

noop
anticipatory
deadline
cfq

In Red Hat 6 the anticipatory I/O scheduler has disappeared…

There are multiple documents stating that deadline I/O scheduler is the preferred choice when running Oracle databases.
cfq scheduler is the default one on Red Hat edition while Oracle has chosen to activate deadline scheduler by default
on its Unbreakable Enterprise Kernel (uek) kernel branch. Which tend to say that it is the one to use when running Oracle databases.

You can change it, dynamically per disk device, by modifying below file:

# echo deadline > /sys/block/${ASM_DISK}/queue/scheduler

[root@server1 ~]# cat /sys/block/sda/queue/scheduler
noop anticipatory deadline [cfq]
[root@server1 ~]# echo deadline > /sys/block/sda/queue/scheduler
[root@server1 ~]# cat /sys/block/sda/queue/scheduler
noop anticipatory [deadline] cfq

http://docs.oracle.com/database/121/CWLIN/prelinux.htm#CHDCEBCD
http://blog.yannickjaquier.com/linux/red-hat-oracle-enterprise-linux-io-tuning-for-oracle-databases.html

RHEL6.x Tuning Virtual Memory

swappiness

    A value from 0 to 100 which controls the degree to which the system
swaps.A high value prioritizes system performance, aggressively swapping
processes out of physical memory when they are not active. A low value
prioritizes interactivity and avoids swapping processes out of physical
memory for as long as possible, which decreases response latency. The
default value is 60.
    A high swappiness value is not recommended for database workloads.
For example, for Oracle databases, Red Hat recommends a swappiness value
of 10.

    vm.swappiness=10

https://access.redhat.com/documentation/en-US/Red_Hat_Enterprise_Linux/6/html/Performance_Tuning_Guide/s-memory-tunables.html

https://www.linkedin.com/groups/echo-3-proc-sys-vm-59573.S.5928598366660345856?trk=groups_guest_most_popular-0-b-ttl&goback=.gmp_59573

http://en.wikipedia.org/wiki/Swappiness

https://www.netroby.com/view.php?id=3687