power failure vs slow ups battery failure

power failure vs slow ups battery failure

Post by Jon LaBad » Sat, 09 Sep 1995 04:00:00



How do UNIX/Solaris systems respond if a UPS supply
runs out of battery power and no one is available to
manually shut them down?

I know there is software to automate this, but it is
not currently available at this site and the UPS's are.

I've got several unix boxes including 2 solaris systems
running full time.  Our electrical supply is bad
enough that we probably have 15 - 20 outages a year.
Some in short order during storms; on/off/on/off ...

Fortunately, I have never noted a data loss or file
system corruption due to these failures.  But it is
just a matter of time.  It is also funny how the
various systems are different in their sensitivity
to power "flickers".

jon
--


 4455 Province Line Road        (609) 252-0159
 Princeton, NJ  08540-4322      (609) 683-7220 (fax)

 
 
 

power failure vs slow ups battery failure

Post by Andrew Gabri » Sun, 10 Sep 1995 04:00:00




Quote:

> How do UNIX/Solaris systems respond if a UPS supply
> runs out of battery power and no one is available to
> manually shut them down?

> I know there is software to automate this, but it is
> not currently available at this site and the UPS's are.

> I've got several unix boxes including 2 solaris systems
> running full time.  Our electrical supply is bad
> enough that we probably have 15 - 20 outages a year.
> Some in short order during storms; on/off/on/off ...

> Fortunately, I have never noted a data loss or file
> system corruption due to these failures.  But it is
> just a matter of time.  It is also funny how the
> various systems are different in their sensitivity
> to power "flickers".

We've found Solaris much better in this respect than many
other unixs we use. We also suffer typically 20 outages
a year (generally the UK is does not have this problem,
but our little village does). I am refering to Solaris
x86, so sensitivity to power "flickers" depends on PC's
PSU.

I find that, unless a disc was actually being written to
the instant the power went, it seems to come back up as
'stable' (rather than 'clean') and seems not to require
fscking. Discs that were being written to do seem to be
fscked. However, I've never yet had a corruption due to
power failure which fsck could not fix, and I've had lots
of power failures! I do keep very good backups though.
(System is an NFS and Samba server for some 40 clients.)

We now have the system on a UPS, but there is no UPS
protection for any of the means to access the system.
Thus, the system has normally been quiet for some time
when the UPS battery dies. The result is that all the
filesystems come back up as 'stable' and don't even
need fscking.

I also don't configure the UPS software to shut down
the system just before battery runs out, because there
is a bug in it. (If the power comes back whilst the
system is shutting down, it still continues to shut
down and stays down; this is unacceptable to us.)

We don't run ODS or prestoserve.

YMMV.

--



 
 
 

1. power failure vs slow ups battery failure

we sell ups power protection for sun machines so here goes.
1. if your ups has an rs-232 port or dry contacts on the back you can
probably buy off the shelf software for sun. making it work is simple, but
the cable can be a troublesome project.
2. Some of the vendors who make ups shutdown software are Systems
enhancements, APC, upsonics, us, ETI, Etc. All are easy to install, and
give different features. I recommend going with the easiest. Ours for
instance will give a sun script to actually reboot the computer after
power is returned thru the main power.
3. you can also buy extended batteries from most people to get like 12-24
hours of battery protection. but it takes room,
4. i recommend you get the brand name off of your ups, and call the
manufacturer, not the distributor, as it is a small sale to them and most
have no clue as to what they are selling.
5. system enhanc is in St. Louis ?
    upsonics=1800upsonics
    us=8002095556
    apc8008904272
    eti=4195224466

Powerstar Inc.                                                  UNIX
,SCSI, UPS Technologies
Gaithersburg Maryland
800-209-5556
fax 301-948-0715

2. Why I'm dumping Linux, going back to Windblows

3. Power Failure Test Failure

4. Programmatically retrieving LVM performance statistics

5. on /etc/mtab vs. /proc/mounts (Was RE: Linux should better cope w ith power failure)

6. Using Zeos to run linux

7. Newbie vs linux: Modem locked after power failure.

8. (Konqueror): smb:/<NT4 PDC> authentication problem??

9. Backup power, power failures, and crashes

10. Power On after power failure not working (Motherboard M787CLR/M787CL)

11. SSA multi-initiator RAID adapter cache battery failure

12. Ioplanar battery test failure

13. Promoting switch failures to node failures (HACMP 4.4)