How to check software RAID status?

westcomlimited

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#1
I have a relatively new install of Elastix that I cannot remember if I setup software RAID on or not when I installed it.

If there some way I can tell if it is Mirrored?

I tried running cat /proc/mdstat but all it returned was:

Personalities :
unused devices: <none>

This looks to me like it is not RAID or it is not detecting it correctly.
 

dicko

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#2
Your disk partitions will be exposed with:-

cat /proc/partitions

Real Raids will usually expose themselves here, the won't be /dev/hda? or /dev/sda?
, mostsocalled motherboard raids are software based, and to be honest , are far worst preforming and more error prone than a linux software raid.
 

dicko

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#3
Your disk partitions will be exposed with:-

cat /proc/partitions

Real Raids will usually expose themselves here, the won't be /dev/hda? or /dev/sda?
, mostsocalled motherboard raids are software based, and to be honest , are far worse preforming, un-tunable and more error prone than a linux software raid.
 

westcomlimited

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#4
Here is the output of that command
major minor #blocks name

8 0 78156288 sda
8 1 104391 sda1
8 2 78051802 sda2
8 16 78156288 sdb
8 17 78156193 sdb1
253 0 152043520 dm-0
253 1 4128768 dm-1


Looks like it is Mirrored?

In case it wasn't clear I am asking about a Elastix installed Software Mirror, not any other type of RAID.
 

dicko

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#5
Not at the Centos OS level vm extends your root across two drives and you only have a boot partion on sda , good luck when a drive breaks :)

dicko
 

fmvillares

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#6
agree with dicko ...buy a real raid 1 system...you re not protected right now
and 1 item to share...if a file gets corrupted in a raid or the particion breaks the raid will be copying across the mirror that information also...so any raid 1 or 5 or 10 only protects you of hardware failures...not errors up to the software world...
 

westcomlimited

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#7
I am aware of how RAID works thanks so I am of course aware that it will not protect against software failure.

Perhaps you misunderstood the term "software RAID"
What I thought was common knowledge is that software RAID is setup by an OS and not a battery backed up hardware controller.

I admit I am not very linux savy, but all I want is to setup a linux software RAID mirror for elastix.

It was my impression that Elastix could do this at installation, are you saying that this is not the case?
 

dicko

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#8
Yes you can as you install Elastix by manually partitioning the two drives, I suggest something like for a raid 1 :-

100 M for /boot use /dev/sda1 and /dev/sdb1 as /dev/md0
1.5 * memory for swap use /dev/sda2 and /dev/sda2 as /dev/md1
6G for / use /dev/sda3 /dev/sdb3 as /dev/md2
the rest for /var use /dev/sda4 /dev/sdb4 as /dev/md3

make each partition of type fd (raid partition), then build the md0-md3 from those partitions.

Alternatively do a mondoarchive iso/usb/nfs image, and restore from that into a manually prepared partition system, (much like the above) you'll need to do a little RTFM'ing to get the handle of mondoarchive/mondorestore do the expert thing and issue an export TERM=vt100 so you don't go blind :)

It is possible to migrate to raid "on the fly" there are a few recipes here and else where, but it's a little ballsy and you will need a third disk temporarily as the default partitioning uses volume manager and extends everything over both drives.

When done, make sure grub is installed on both /dev/sda and /dev/sdb

(I'm sure you also know not to confuse a real raid controller with a cheap motherboard raid controller, I say this as your posted bug says you have a raid 5 hardware controller, but your previous post seems to identify two raw scsi/sata disks )
 

westcomlimited

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#9
OK thanks again Dicko

My bug report is from a different machine to what I am wanting to RAID, as you said that machine has a hardware RAID 5.
 

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