raid or not raid

[illoai at gmail.com]

On 24/05/07, kalin mintchev <kalin at el.net> wrote:
> >> >
> >> > i have a box in a remote hosting facility that claims that the machine
> >> has
> >> > two discs raided in it but df and fstab show only one disc with a
> >> bunch of
> >> > slices.
> >> > under devices there is another name - ad6 - but it's not mounted
> >> anywhere.
> >> > the one i see both in df and the fstab is ad4 with one big slice and
> >> > different partitions....
> >> >
> >> > they insist there are 2 raided discs in tha machine. the os is 5.4 and
> >> i
> >> > think at that point the raid drivers were still considered
> >> 'experimental'.
> >> >
> >> > it makes sense to me that if i don't see a second drive in the fstab
> >> there
> >> > isn;t any mounting which means that there is no raid going on...
> >> >
> >> > is there any other way i can make sure if raid is actually on?
> >> > would there will be any logs somewhere?
> >> > the machine has been up for about 2 years and the dmesg is long
> >> gone...
> >> >
> >> > thanks.....
> >> >
. . .
> > A proper RAID will show up as a single device,
> > just like any hard drive (but different).
>
> what do you mean by 'but different'? the actual df output lists this:
>
> # df -h
> Filesystem     Size    Used   Avail Capacity  Mounted on
> /dev/ad4s1a    290M     81M    186M    30%    /
> devfs          1.0K    1.0K      0B   100%    /dev
> /dev/ad4s1d    989M     50K    910M     0%    /tmp
> /dev/ad4s1f     15G    5.0G    8.4G    37%    /usr
> /dev/ad4s1e    989M     33M    877M     4%    /var
> /dev/ad4s1g    126G     90G     25G    78%    /work
>
> i read it as one disk - ad4 - with one big slice 1 and 5 partitions.
> am i wrong? fstab shows same devices.
>
> > It does seem odd to me that a (supposed) RAID
> > would show up as /dev/ad4.
>
> please elaborate. do you mean that the raided disks will have another
> id/name rather than 'ad'?

Not knowing what hardware you have, I would still hazard
that a RAID device will not show up as /dev/adN.
I would guess that the RAID controllers that use cam
might have their devices called by the /dev/daN convention,
but I don't know that.

> ok. i guess i'd explore the 'interesting phone calls' one.
> if it doesn;t walk like a duck and it doesn;t quack like a duck it must be
> some other bird/thing...
>

I would agree with that.

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