OK, this is a valid explanation. Still, i suggest you use smaller disks for your rootvg. In my experience it is best to put only filesystems really really belonging to the system (not the application, not the data, not anything else) into the rootvg. First, when you take a system backup you back up the rootvg, aka mksysb. Guess, how long that takes on a multi-terabyte rootvg and, bonus question, how big of a size the resulting mksysb-image will be. For reference, my largest database server (700G memory, ~80TB database) has a (2x, mirrored) 120GB rootvg - and this is only because the customers insisted on swap space that will never be used. Otherwise i would have gone with our 2x60GB-standard-rootvg.
Second, modern systems are usually virtual and the disks are too. There is a big difference in moving around system disks (controlled by VIOS) and non-system disks because these can be unmounted/varyoffed easily while the system is under load. Therefore it is a good idea to separate system- and non-system-disks into seaparate VGs.
First off: thank you for telling us that! I perhaps never would have had that idea at all and so i (and all the others reading this thread) learned something from here too. Absolutely commendable! A word of caution too: you shouldn't just overwrite parts of the system. AIX has a great packaging system and i suggest you use it to your advantage:
- check which package the file came from with
then replace this package with a newer version.
- if you are interested in which else files the package contains issue
to get a list of files/directories belonging to this package.
I hope this helps.
bakunin
Thanks! Yes, I agree this system should not have been installed on such large disks. There are a couple of 300GB disks in there that I think the rootvg should go on. I am new to this company and wasn't involved in installing the makesysb image. However, it is new and not in production yet, I may make the recommendation we move it to the other disks. Most of our systems do use virtual disk, however I think due to the particular function of this server they decided to install locally.
Thanks for the info about the packages, I will look into that! I have been a Unix/Linux SA for 15 years, but am very new to AIX, so I appreciate the advice.
------ Post updated at 10:06 AM ------
Just for some additional information, it looks like this problem existed on all the servers we had running AIX 7100-03-04-1441. The fileset for the dumpcheck script was bos.sysmgt.serv_aid 7.1.2.0.
Hi All,
is there any way to find out the optimal/would be size of the cor dump file generated by the system while a process got terminated abnormally?
Basically we have been asked to provide the size of the core dump file being generated by the administrators who maintained the UNIX boxes.... (4 Replies)
Friends, while taking backup on /dev/rmt/0cn it is showing device does not exists.
I have checked /dev/rmt 0cn is present there with link file created in /devices/pci@8,700000/scsi@5/st@5,0:cn
I have checked cd /devices/pci@8,700000/scsi@5 but st@5,0:cn is not there. But I found st@3,0:cn.
... (3 Replies)
1.what is dump device in AIX?...
2. i m getting this error message
The largest dump device is too small.
when i check the paging space , it is used only 41%
any help welcome (4 Replies)
Hey guys - I have made this script and for some reason, I dont see time stamp as "Month-Day-YYYY Hours-Mins" - all i see is Month and Day.
Also, my file size is approximated. For example, if the size is 19,606KB - the script shows as 20M. Is there a way to see the exact file size?
How do i... (2 Replies)
Hi,
I have a very frustrating issue! I hope you guys can assist
When a disk is presented out the iSCSI target display a lower disk capacity
SOLARIS VERSION is SOLARIS 10 05/09 Kernel Patch 139555-31
ISCSI Patch 119090-31, 141878-11
Unix Commands To discover Target
bash-3.00# i... (0 Replies)
E87EF1BE 0605150011 P O dumpcheck The largest dump device is too small.
bash-3.00$ errpt -aj E87EF1BE | more
---------------------------------------------------------------------------
LABEL: DMPCHK_TOOSMALL
IDENTIFIER: E87EF1BE
Date/Time: Sun Jun 5 15:00:01... (4 Replies)
Hi
how to change the primary dump device in a vio server ?
$ ioslevel
2.2.0.11-FP-24 SP-01
$ oem_setup_env
# sysdumpdev -l
primary /dev/sysdumpnull
secondary /dev/hd6
copy directory /var/adm/ras
forced copy flag TRUE
always allow dump TRUE
dump... (1 Reply)
Hi all
I have a query about dump device in aix, i asked this question on interview.
what is dump device, how to add dump device & its work.
kindly give this answer,
thanks in advance.
:confused: (1 Reply)
Hello Guys,
I need a little help here. I have been studying crash dump and per what I am reading, you can dedicate a slice to use as a dump device. Now when you dedicate this slice, do you have to :
1) create a mount point?
2) add entry in /etc/vfstab?
3) is this slice wu or wm?
4) should... (3 Replies)
Hi,
This is Solaris-10 box and in few of file-system (root file-system of non global zones), usage/available is not showing correct size. I am not able to figure out, what is eating up this space.
Global Server - bdrpod01
Non Global zone - bdrpod01-zputq01
root@bdrpod01:/root# df -h... (2 Replies)
Discussion started by: solaris_1977
2 Replies
LEARN ABOUT DEBIAN
savecore
savecore(1M) System Administration Commands savecore(1M)NAME
savecore - save a crash dump of the operating system
SYNOPSIS
/usr/bin/savecore [-Lvd] [-f dumpfile] [directory]
DESCRIPTION
The savecore utility saves a crash dump of the kernel (assuming that one was made) and writes a reboot message in the shutdown log. It is
invoked by the dumpadm service each time the system boots.
savecore saves the crash dump data in the file directory/vmcore.n and the kernel's namelist in directory/unix.n. The trailing .n in the
pathnames is replaced by a number which grows every time savecore is run in that directory.
Before writing out a crash dump, savecore reads a number from the file directory/minfree. This is the minimum number of kilobytes that must
remain free on the file system containing directory. If after saving the crash dump the file system containing directory would have less
free space the number of kilobytes specified in minfree, the crash dump is not saved. if the minfree file does not exist, savecore assumes
a minfree value of 1 megabyte.
The savecore utility also logs a reboot message using facility LOG_AUTH (see syslog(3C)). If the system crashed as a result of a panic,
savecore logs the panic string too.
OPTIONS
The following options are supported:
-d Disregard dump header valid flag. Force savecore to attempt to save a crash dump even if the header information stored on
the dump device indicates the dump has already been saved.
-f dumpfile Attempt to save a crash dump from the specified file instead of from the system's current dump device. This option may be
useful if the information stored on the dump device has been copied to an on-disk file by means of the dd(1M) command.
-L Save a crash dump of the live running Solaris system, without actually rebooting or altering the system in any way. This
option forces savecore to save a live snapshot of the system to the dump device, and then immediately to retrieve the data
and to write it out to a new set of crash dump files in the specified directory. Live system crash dumps can only be per-
formed if you have configured your system to have a dedicated dump device using dumpadm(1M).
savecore -L does not suspend the system, so the contents of memory continue to change while the dump is saved. This means
that live crash dumps are not fully self-consistent.
-v Verbose. Enables verbose error messages from savecore.
OPERANDS
The following operands are supported:
directory Save the crash dump files to the specified directory. If directory is not specified, savecore saves the crash dump
files to the default savecore directory, configured by dumpadm(1M).
FILES
directory/vmcore.n
directory/unix.n
directory/bounds
directory/minfree
/var/crash/'uname -n' default crash dump directory
ATTRIBUTES
See attributes(5) for descriptions of the following attributes:
+-----------------------------+-----------------------------+
| ATTRIBUTE TYPE | ATTRIBUTE VALUE |
+-----------------------------+-----------------------------+
|Availability |SUNWcsu |
+-----------------------------+-----------------------------+
SEE ALSO adb(1), mdb(1), svcs(1), dd(1M), dumpadm(1M), svcadm(1M), syslog(3C), attributes(5), smf(5)NOTES
The system crash dump service is managed by the service management facility, smf(5), under the service identifier:
svc:/system/dumpadm:default
Administrative actions on this service, such as enabling, disabling, or requesting restart, can be performed using svcadm(1M). The ser-
vice's status can be queried using the svcs(1) command.
If the dump device is also being used as a swap device, you must run savecore very soon after booting, before the swap space containing the
crash dump is overwritten by programs currently running.
SunOS 5.10 25 Sep 2004 savecore(1M)