[CentOS] RAID help

Thu Dec 16 15:47:08 UTC 2010
Brunner, Brian T. <BBrunner at gai-tronics.com>

      Philix T A [philixlinux at gmail.com] wrote

	2) Dont create RAID for swap and / root partition (Not

I would avoid putting / or /swap on RAID0 partitions, but RAID1 should
not only not be a problem, it should be encouraged as a method of
recuperating from a spindle failure.

	3) Swap Size size should be 2X the size of the Physical memory

That was the other millennium, when it was certain that our programs
used more Core/RAM than you had in your box.  This is now, when you need
swap only when you can't schedule your process load to not over-demand
RAM, and you can't put more RAM in your box.  In that kind of case, a
larger box is more cost-effective than swap.  I make certain swap is
never used. Man 1 vmstat, look at the 'si' and 'so' fields, they should
stay zero.

	4) Always partition which uses high read/write to the disk  eg
/var/log /var/www/html  and /home etc
I'm not certain I understood what you said.  My advice on partitioning
is to group read-only (e.g. most of / & /usr) on partitions mounted -o
ro, and writable portions (e.g. most of var) on a separate partition so
the amount of fsck recovery is minimized.  The OP asked about making a
single partition for everything, this is (approximately) what a Red Hat
default install will do.  Making a RAID1 of everything is not a bad
idea, it's called a backup ;)

	6) My experience had always shown if your apps had memory leak ,
expect Swapping to happen for sure,  where reboot of the apps or the
system is needed

Buggy software (memory leaks included) should simply be avoided.  Where
they can't be avoided, a crontab entry to kill & restart every hour (or
so).  I'm not sure what the OP is asking.

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