Problem with SWAP device on HPUX 11.00

[Hemalatha_1]

AFter a system board replacement on HP A CLass 9000 Series, the SWAP device (configured in /vg00/lvol2) is reporting error. Specifically the error is returned from the Diagnostic System at startup,reporting excessive I/O logging. The system is stuck here for about 3 min , then finally the dump device /swap device is ignored and the system starts. Running swapinfo -ta reports that the volume on which swap is resident is disabled. What will be the consequences on the system performance and how can this problem be rectified?

Thanks in advance

[Steven E. Protter]

Shalom,

You should be able to fire up sam, and redo the swap/dump area anew.

It may require a couple of boots, one to get rid of it, one to reconfigure it.

You will need to make sure all the disks are actually working before you do this.

Having an Ignite make_tape_recovery tape handy is a good idea.

The dump not being used error is significant.

You need also to make sure device swap is enabled in the kernel.

Your system should improve performance once it has swap properly configured.

SEP

[Prashanth Waugh]

Hi Hemlata,

How many swap devices had configerd on ur system before the board replacement

Regards
Prashant

[Prashanth Waugh · Accepted solution]

Hi Hemalatha,

first give me the #swapinfo -tam output here. I think its a problem regarding secondary swap space. If the primary swap is working then and secondary device swap space is not working fine .Then your system may hamper performance point of view. the system will be sluggish when the load on system will increase and the physical mem and 1ry swap space is insufficent.

Regards
Prashant

[Prashanth Waugh]

Hi Hemlata,
u mention that volume on which swap is resident is disabled.use the below command for testing vg
#lvdisplay /dev/vg00/lvol2
#vgdisplay /dev/vg00

Regards
Prashant

[Prashanth Waugh]

Hi Hemlata,

Have u taken the ignite backup before replacing the board .Take the ignite backup

=========================================================
Here I am giving the prcedure for addition of device swap.pls convert it according to ur requirment.you take your decision according to situation. If you have any doubt pls revert back.

1)lvcreate -C y -r n -m 1 -L 8192 -n lvol2 /dev/vg01
L logical volume size in MB
m for mirring the swap space
2)create an entry in /etc/fstab
/dev/vg01/lvol1 . swap pri=1
You decide the priority according to ur requirment
3)activate it using
swapon -a

Regards
Prashant

[Prashanth Waugh]

Hi Hemalatha,

I missed one step. after first step the second step should be
2)swapon -p 1 /dev/vg01/lvol2

Regards
Prashant

[Prashanth Waugh]

Hi ,

Check the /var/adm/syslog/syslog.log

Regards
Prashant

[Hemalatha_1]

Hi

Being a first time user of this forum , I am mighty impressed by the response.Thanks SEP and thank you too Prashant, for such prompt replies. We have a normal file system backup of the root volumes.

This is the output of swapinfo -tam
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev - - - - 0 - 0 /dev/vg00/lvol2 disabled
reserve - 0 0
memory 401 132 269 33%
total 401 132 269 33% - 0 -


The portion of the syslog.log where the error occurs is :

Aug 29 03:32:56 hpaclass vmunix: Swap device table: (start & size given in 512-byte blocks)
Aug 29 03:32:56 hpaclass vmunix: entry 0 - major is 64, minor is 0x2; DIAGNOSTIC SYSTEM WARNING:
Aug 29 03:32:56 hpaclass vmunix: The diagnostic logging facility has started receiving excessive
Aug 29 03:32:56 hpaclass vmunix: errors from the I/O subsystem. I/O error entries will be lost
Aug 29 03:32:56 hpaclass vmunix: until the cause of the excessive I/O logging is corrected.
Aug 29 03:32:56 hpaclass vmunix: If the diaglogd daemon is not active, use the Daemon Startup command
Aug 29 03:32:56 hpaclass vmunix: in stm to start it.
Aug 29 03:32:56 hpaclass vmunix: If the diaglogd daemon is active, use the logtool utility in stm
Aug 29 03:32:56 hpaclass vmunix: to determine which I/O subsystem is logging excessive errors.
Aug 29 03:32:56 hpaclass vmunix: ignored - can't write to device
Aug 29 03:32:56 hpaclass vmunix: ERROR: dump device 64:0x2 cannot be used and will be ignored:
Aug 29 03:32:56 hpaclass vmunix: device is read-only
Aug 29 03:32:56 hpaclass vmunix: WARNING: no swap device configured, so dump cannot be defaulted to primary swap.
Aug 29 03:32:56 hpaclass vmunix: WARNING: No dump devices are configured. Dump is disabled.
Aug 29 03:32:56 hpaclass vmunix: Warning: file system time later than time-of-day register
Aug 29 03:32:56 hpaclass vmunix:
Aug 29 03:32:56 hpaclass vmunix: Getting time from file system
Aug 29 03:32:56 hpaclass vmunix: Starting the STREAMS daemons-phase 1

How do I check the integrity of the disk space in lvol2 where the dump has been configured? How can I through command line, enable lvol2 where the dump device is resident?

I would like to check these things before I create/recreate the swap space. Thanks again .

Hemalatha

[Prashanth Waugh]

Hi Hema,


u mention that volume on which swap is resident is disabled.use the below command for testing vg
#lvdisplay /dev/vg00/lvol2
#vgdisplay /dev/vg00
Also try
#swapon -a
fpr activating swap space

[Deepak Kr]

Yes, you need to what went wrong and fix it first before you choose other method.

#swapinfo -tam

e.g

Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev - - - - 0 - 0 /dev/vg00/lvol2 disabled
reserve - 0 0
memory 401 132 269 33%
total 401 132 269 33% - 0 -



start SAM using
#sam
select:SAM Disks and File Systems
select: SAM Swap

select using spacebar:Primary Swap: /dev/vg00/lvol2

press tab and choose modify from action under menu


Modifying Swap On: /dev/vg00/lvol2

When To Enable: (optional)

[X] Now

[X] At Every System Boot

check both options if uncheck and if it asks for reboot you need to reboot. So make sure you take downtime for this reboot.


Now once you reboot you must be able to see:

#swapinfo -tam

Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 2048 0 2048 0% 0 - 1 /dev/vg00/lvol2

If everything fine then no issues.

as far as adding another swap space addition is concern you can take that action anytime even when system is online.

[Deepak Kr]

prashant wrote>>>

1)lvcreate -C y -r n -m 1 -L 8192 -n lvol2 /dev/vg01
L logical volume size in MB
m for mirring the swap space
<<<<<<<

Actually using m for mirroring in lvcreate for a swap device is not at all required here as we dont need data to be intact or saved under swap.

So running following commands will help you to add secondary swap at any time later

#lvcreate -C y -r n -L
enable newly created swap
#swapon -p 0 /dev/vgname/swapvol

update /etc/fstab to make secondary swap permanent even after reboot
# echo "/dev/vgname/swapvol ... swap pri=0 0 0" >> /etc/fstab

run swapinfo to verify

#swapinfo -a
e.g
Mb Mb Mb PCT START/ Mb
TYPE AVAIL USED FREE USED LIMIT RESERVE PRI NAME
dev 2048 0 2048 0% 0 - 1 /dev/vg00/lvol2
dev 4092 845 3247 21% 0 - 0 /dev/vgswp/lvswp1
reserve - 7486 -7486
memory 6192 1005 5187 16%
0 -

[Dennis Handly]

Note: You can also add filesystem swap to get you going.

[Rasheed Tamton]

Tips to check:

grep -i swap syslog.log
grep -i swap /etc/rc.log
ll /sbin/rc1.d/S500swap_start (it should be linked to /sbin/init.d/swap_start)

I guess, the system might have panicked/rebooted piror to the replacement of the system board. In that case there is a possibility savecrash might have locked and disabled the device. Check you have a file called /etc/savecore.LCK

man savecrash would give you more info

Regards.

[Prashanth Waugh]

Hi Hema,

R u able to enable the swap.

Regards
Prashant

[Hemalatha_1]

I tried everything ; Suggestions from Prashant lvdisplay does display lvol2
swapon -a too done. Same problem.

Tried through SAM, the entry was missing. When I tried to add the device lvol2 to SWAP, as suggested by Deepak, it returns an error saying that the device is marked read only.

I wonder how the entry could be missing from SAM. Running the system only for critical operations without the dump & swap at the moment.

Will appreciate if any of you could help.

Thanks a ton to Prashant,Deepak, Dennis & Rasheed.

[Hemalatha_1]

grep -i swap syslog.log
reports the SWAP portion could not be configures
grep -i swap /etc/rc.log
reports SWAP is enabled.
ll /sbin/rc1.d/S500swap_start (is linked to /sbin/init.d/swap_start)

/etc/savecore.LCK does not exist.

Further I also checked in the Logical Volume Manager through SAM, lvol2 has both read/write permissions. Same is displayesd through lvdisplay /dev/vg00/lvol2.

Can the Bad Space Relocation be turned on ? At the moment contigious allocation is checked.

Hemalatha

[Deepak Kr]

Hema,

what about adding a new swap space?

Have you did that?

[Prashanth Waugh]

Hi Hema,

Check swapmem_on kernal parameter

#kmtune -lq swapmem_on
Its value should be 1.kmtune is on 11.11
==========================================
if os is 11.23 then use kctune

Regards
Prashant

[Dennis Handly]

>Prashant: Check swapmem_on kernel parameter

No need to do that. The system won't work unless there is either device or pseudo-swap and Hemalatha's "swapinfo -tam" showed the latter exists.

[Hemalatha_1]

Finally we created a secondary file system swap, of 200MB (512 MB RAM on server). The performance is marginally improved. The device swap configured on /vgoo/lvol2 is getting marked as readonly after reporting I/O errors. I guess this could be due to a physical disk problem. I want to know if I can drop the lvol2 and recreate it as swap/dump device.

Thanks everybody

[Hemalatha_1]

Looks like the disk has to be replaced. The only option left. Forum was useful in performing various checks to come to the conclusion