Not enough free space to shrink the file system issue in AIX

Recently got an issue in reducing jfs2 filesystem  with osverion 6.1 and have enough space to reduce filesystem.

root@umaix /tmp>df -g /orafs1
Filesystem    GB blocks      Free %Used    Iused %Iused Mounted on
/dev/oralv1   100.00    75.00   25%      555     1%  /orafs1

root@umaix /tmp>chfs -a size=-15G /orafs1
chfs: There is not enough free space to shrink the file system.

This issue will occur whenever you try to reduce big chunk of data ( in this case 15GB) that may not be contiguous in the file-system because you have files scatted everywhere.

Try   the following methods one by one until your issue fixed

1. Try to defrag the FS:

#defragfs -s /orafs1

2. Reduce in smaller chunks:

If you still can't reduce it after this. Try reducing the filesystem  in smaller chunks. Instead of 15G at a time, try reducing 1 or 2 gigs. Then, repeat the operation.

3. Check the processes:

Sometimes processes open big files and use lots of temporary space in those filesystem.
You could check processes/applications running against the filesystem and stop them temporarily, if you can.

#fuser -cu[x] <filsystem>

4. Move the large files and try shrink

Try looking for files large using the find cmd and move them out temporarily, just to see if we can shrink the fs without them:

#find /<filesystem> -xdev -size +2048 -ls|sort -r +10|pg

Finally the last method, the alternative approach if any one of above methods are not working then go for filesystem recreation.

==> You should be very care full , need to take fs backup and as well as approach application before removing the filelsystem.

5) Recreate filesystem:

• - Take databackup of the fielsystem  ( very Important,dont skip this )
  Either you can take using your backup tools like TSM / netbackup or move data to a temporary   directory


• - Remove the  filesystem  (  #rmfs /orafs)
• - Create the filesystem again
   #mklv -y oralv1 -t jfs2 oravg 600  ( in this case we need 75GB and pp size is 128)
   #crfs -v jfs2 -d oralv1 -m /orafs1 -A yes  (create orafs1 filesystem)


• - Restore data to the filesystem
• - Verify fs size

root@umaix /tmp>df -g /orafs1
Filesystem    GB blocks      Free %Used    Iused %Iused Mounted on
/dev/oralv1   75.00    50.00   33%      555     1%  /orafs1

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How to mirror VIOS Boot Disk?

Here is the procedure to mirror VIOs boot disk.

# lspv
NAME             PVID                 VG               STATUS
hdisk0           00c122d4341c6e62     rootvg           active
hdisk1           00cd55a4fg6b676f     None
hdisk2           00c5524409a99b77     None

Here hdisk0 is rootvg disk , now we need to check free disk.
you can use lspv -free command to check the un-mapped free disks.

$ lspv -free
NAME            PVID                                SIZE(megabytes)
hdisk1         00cd55a4fg6b676f                     256000
hdisk2         00c5524409a99b77                     256000

So In this case, hdisk1 is free and un-mapped . So we're going to use hdisk1 to mirror with hdisk0.

Add hdisk1 into rootvg:

# extendvg rootvg hdisk1 0516-1254 extendvg: Changing the PVID in the ODM.

Now mirror the disk but defer the automatic reboot:

$ mirrorios -defer hdisk1

Now check the boot list:

$ bootlist -mode normal -ls
hdisk0 blv=hd5 pathid=0

We only have hdisk0 at the moment.  Need to add hdisk1 into this:

$ bootlist -mode normal hdisk0 hdisk1

Check that worked:

$ bootlist -mode normal -ls
hdisk0 blv=hd5 pathid=0
hdisk1 blv=hd5 pathid=0

You now have a mirrored rootvg. 

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