While cleaning up some bash scripts tonight, I started to wonder which of the following two substitutions is clearer:
$ echo {foo=(ls)}
Desktop Documents Library Movies Music Pictures Public SUMS Sites
or
$ echo {foo=ls}
Desktop Documents Library Movies Music Pictures Public SUMS Sites
I really think the second form is a bit more clear, though it could throw off people who get ` and ' mixed up! Choices, choices!
Veritas Volume Manager comes with a wide variety of command line utilities, which can be used to create, delete and maintain Veritas objects. When operations are performed with the CLI and no disk group is passed to the “-g” (disk group to use) option, the command will default to using the value assigned to defaultdg. This value of defaultdg is stored in the /etc/vx/volboot file:
$ grep defaultdg /etc/vx/volboot
defaultdg oradg
If you would like to change the default disk group, you can use vxdctl(1m)‘s “defaultdg” option:
$ vxdctl defaultdg oof
To verify that the value was changed, you can run vxdg(1m) with the “defaultdg” option:
$ vxdg defaultdg
oof
This can save a lot of typing when creating new Veritas objects!
If you manage PF firewalls, you might want to check out my PF monitoring article in this months SysAdmin magazine. The article describes fwanalog, pftop, pfstat, pftctl, and some cool tcpdump flags!
While reading through Mike Shapiro’s FMA presentation today, I came across two cool new hardware technologies. The first is FBDIMM, which Micron describes as:
Address/command soft errors can disrupt server performance and reliability. To help lessen their occurrence, Micron’s FBDIMMs incorporate an enhanced cyclic redundancy check (CRC) that provides greater data and address/command protection than traditional server modules.
Designers can also configure it to suit their particular applications. Providing an even greater defense, the bit lane fail-over correction feature identifies bad data paths and removes them from the operation. Together, these error detection methods dramatically reduce address/command soft errors.
The second technology is CPU chipkill, which Findany ISP describes as:
CHIPKILL - A technology developed by IBM for servers and other systems that demand high availability. It allows a computer motherboard and BIOS to detect problems with the computer’s memory and selectively disable problematic parts of the memory. Depending on the technology used, this technology may or may not require specialized memory chips.*
Hopefully Fujitsu and Sun will integrate these technologies into their next generation APL server line.
While booting my Solaris 10 box today, I noticed the following error in /var/adm/messages:
Jul 23 11:15:53 tigger metadevadm: [ID 209699 daemon.error] Invalid device relocation
information detected in Solaris Volume Manager
Jul 23 11:15:53 tigger metadevadm: [ID 912841 daemon.error] Please check the status of
the following disk(s):
Jul 23 11:15:53 tigger metadevadm: [ID 702911 daemon.error] c1t6d0
I recently replaced c1t6d0, but forgot to update the device relocation information in the meta state database. To fix this issue, I ran metadevadm(1m) with the “-u” (update diskid in the meta state database) option:
$ metadevadm -u c1t6d0
Updating Solaris Volume Manager device relocation information for c1t6d0
Old device reloc information:
id1,sd@SSEAGATE_SX318203LC______LR834657____1024048T
New device reloc information:
id1,sd@SSEAGATE_SX318203LC______LR22875200001004H76G
Now metadevadm doesn’t complain when the box boots! :)