swap

[srinivasa rao vaddadi]

Hello All,

Today i got one more error .please check the below error message and guide me what exactly i need to do.i think i have to change maxswapchunks , do i need to restart the server if i want to change. offcourse tell me if this is the cause.

Error

Wed Nov 8 19:24:56 PST 2000 $
Memory Information:
physical page size = 4096 bytes, logical page size = 4096 bytes
Physical: 2097152 Kbytes, lockable: 1567644 Kbytes, available: 1807032 Kbytes

Unable to add all swap for device: /dev/vg00/swap. Increase the tunable parameter maxswapchunks by 136 and re-configure your system.
xdr_opaque: decode FAILED
NOTICE: nfs_server: bad getargs for 2/16

[Arunvijai_4]

Yes, You have to change maxswapchunks as the error specifies. What is your current maxswapchunks value ?

# kmtune|grep -i maxswapchunks


-Arun

[Muthukumar_5]

Get kernel parameter information with kctune or kmtune. Tuning of that parameter is needed to occupy more swap memory.

refer http://docs.hp.com/en/1219/tuningwp.html#maxswapchunks
for more.

hth.

[RAC_1 · Accepted solution]

There is settings that define swap space configurable. maxswapchunks. swapchunk size is 2MB. so to have swap space of say 4000MB, you need to have maxswapchunks setting of 2000.

But it is a lot wiser to set it little higher. so when you need to add swap, you will not have to compile a kernel. Chaning this parameter will require a reboot.

In your case, set it as follows.
"current_maxswapchunks_setting + 500"

[Muthukumar_5]

# kmtune -q maxswapchunks -l
will give related details.

# kmtune -q maxswapchunks -l
Parameter: maxswapchunks
Current: 1024
Planned: 1024
Default: 256
Minimum: -
Module: -
Version: -
Dynamic: No

It will give current details and planned thing. You have to tune and upgrade kernel. Use sam to tune and reboot with change.

hth.

[srinivasa rao vaddadi]

Hello All,

our swap space is 8400MB and our amxswapchunks is as follows . so what is the value i have to set. and will it effect to any other applications.

# kmtune -q maxswapchunks -l
Parameter: maxswapchunks
Current: 2000
Planned: 2000
Default: 256
Minimum: -
Module: -
Version: -
Dynamic: No

[Muthukumar_5]

Change maxswapchunks parameter as,

# kmtune -s maxswapchunks=2500
# kmtune -u

Reboot the machine if it is suggesting there. And try after that.

hth.

[RAC_1]

8400MB, your maxswapchnuks setting should be 8400/2=4200.

You can set it at 5000 also. This absolutely does not affect any apps.

[Patrick Wallek]

If you are going in and modifying the maxswapchunks kernel parm, then you should go ahead and just max it out. The max value is 16384. This will not hurt anything and will allow you to add more swap at any time without worrying about the kernel.