Extending root filesystem

[masoodasif]

Dear
I need to extend the root file system because we are running out off space my main purpose is to create the 11 2TB mount points.i suspect that for each mount we required 7MB space on root to create VG.For this i need to extend the / file system. NOW the issue is that we cannot afford downtime for this production machine to reignite it. i have Online JFS installed on the server.
i was checking some forums to extending the root file system they are suggesting one procedure to move the lovol 4 to the next location and extend the root .
now my question is that this possible solution . and why the VG is taking 7mb on root.
i m sending BDF command out put

s7dmc # bdf

Filesystem kbytes used avail %used Mounted on

/dev/vg00/lvol3 212992 198768 14168 93% /

/dev/vg00/lvol1 298928 85040 183992 32% /stand

/dev/vg00/lvol8 4718592 2225408 2477856 47% /var

/dev/vg00/lvol7 3080192 1298896 1767448 42% /usr

/dev/vg00/lvol4 212992 42208 170128 20% /tmp2

/dev/vg00/tmp2 1048576 64973 922928 7% /tmp

/dev/vg01/lvoractl 114688 6349 101575 6% /oractl

/dev/vg00/lvol6 2670592 2395992 272480 90% /opt

/dev/vg00/lvORA920 7340032 4547160 2620066 63% /opt/oracle

/dev/vg00/lvol5 2048000 54296 1978184 3% /home

/dev/vg00/fms 5242880 3127816 1985777 61% /fms

/dev/vg03/lvavfile2

524156928 22263896 497972352 4% /avfiles

/dev/vg01/lvAV 40960000 19499560 21320232 48% /avfile2

/dev/vg04/lv3g 2146140160 1241255776 897820920 58% /3g1

s7dbq:/dmc_back 35848192 1503608 34087432 4% /TEMP

s7cs:/depot 12288000 11380296 900056 93% /depot

/dev/vg05/lv3g2 2146107392 68016 2129273456 0% /3g2

/dev/vg06/lv3g3 2146107392 68016 2129273456 0% /3g3

/dev/vg07/lv3g4 2146107392 68016 2129273456 0% /3g4

s7dmc #

[masoodasif]

hi again

is these are the steps to follow or need some modification

pvmove -n /dev/vg00/lvol4 /dev/dsk/
lvextend -L 400 /dev/vg00/lvol3
fsadm -F vxfs -b 400 /

a quick response is highly appreciable

thanks

[MarkSyder]

You almost certainly have something writing to / that should be writing to a dedicated filesystem.

Also check for files type f in /dev: someone may have incorrectly typed a tape device name and created a huge text file.

Final check: do a find for core files and remove any you find.

Mark Syder (like the drink but spelt different)

[Shrikant Lavhate]

Extending root ....

Find experts comment in this thread.
http://forums12.itrc.hp.com/service/forums/questionanswer.do?threadId=1247446

[john korterman]

Hi,

the size of your root file system is ok, and there should be no need for extending it. Generally, the root file system should not contain anything growing very much, but you can perhaps clean it up a little bit. There are many threads suggesting how to do this: make a forum search for "root file system full".
The best way is to look for the directories comsuming most space. A fast, but not very efficient way is to look for big single files, e.g.:
# find / -type f -size +1000000c -xdev -exec ls -l {} \;
which will list all files bigger than 1000000 characters.
But the investigation of what takes up space should determine what can be cleaned up, and you should definitely try that before even attempting to extend the root file system, which would an extremely risky task.

regards,
John K.

[masoodasif]

Dear

thanks For your advice i checked every thing and i cannot remove files from here because all files are used by the application
i want to ask one thing
that FOR VG Creation for about 2TB how much space required on the root because when i m creating the VG then my system will increase the root size to approximately 7-8MB

My main purpose is to add 11x2TB mount points on my system recently i free some space and created 2 VGs and it take approx 14 MB space on my root
so for creating more i need more space on root thats why i want to increase the size

PVMOVE will not serve me in this case like moving LVOL4 to next extent and increasing the space of root
?? please HELP me thanks

[MarkSyder]

"i cannot remove files from here because all files are used by the application"

Isn't that what I said? You have an application writing to / that should be writing to a dedicated filesystem.

Mark

[Ivan Krastev · Accepted solution]

For every new volume group you need 1~10MB space in root file system. This is required for lvm configuration files in /etc/lvmconf/.

For extending root mount point you can try with lvol4 first (/tmp2 200mb) and after that with lvol5 (/home 2GB). An of course you should have a free space in vg00.

For extending the root volume you don't need to break the mirror on all lvols, only on the next (lvol4) after root (lvol3).

Do the following:
1. make a mirror copy of /tmp2 filesystem (lvol4) over new disk - MirrorDisk required.
2. remove mirror on lvol4 from first disk.
3. extend lvol3 (/) with size of lvol4.
4. mirror again lvol4 over old disk.

Before procedure you have:
lvol2
lvol3
lvol4
lvol5
.
.
.
lastlvolfromVG00

and after this you will have:
lvol2
lvol3 (with size lvol3+lvol4)
lvol5
.
.
.
lastlvolfromVG00
lvol4

regards,
ivan

[masoodasif]

Dear Mark

yes u r right that some constant things are already there on the root which i cannot move from root.now my root is still not increasing rapidly but i want to add 11 VGs in it it will almost required 70 to 100 MB on root thats y i want to increase the root.
i already remove some unnecessary files that help to add 2 vgs.
and
Dear ivan
I have some space available on VG00
means on my first disk i have space available can i move my LOVL4 to my vg00 or i need to create LV and MOVE my LV to new LV

means i will create one more LV on the VG00 and mount /test2 to that lvol
and then i will remove my lovol 4 and extend my root ? is it ok aur i will move PV
please suggest

[Ivan Krastev]

Do you have mirror of the lvols? Can you post lvdisplay of lvol4 ?

If /tmp2 is not usable and it is after lvol3 (check with vgdisplay) you can create new lvol and move all data from /tmp2 to the new lvol.
After that umount /tmp2, umount new lvol and mount it as /tmp2.

This will free lvol4 and you can remove it and extend lvol3.

regards,
ivan