Silicon RAID controler

[Heinz Mauelshagen]

On Sun, Sep 25, 2005 at 03:14:23PM +0200, Patrick Ale wrote:
> Hi All,

Hi Patrick.

> 
> I tried the dmraid tool on my Silicon Image raidcontroler and was able to
> query the metadata.
> The metadata shown is correct for the logical volume.
> 
> lilith:/home/patrick# dmraid -r
> /dev/hdi: sil, "sil_afajdfddahad", stripe, ok, 390718720 sectors, data@ 0
> /dev/hdk: sil, "sil_afajdfddahad", stripe, ok, 390718720 sectors, data@ 0
> lilith:/home/patrick# dmraid -s
> *** Active Set
> name : sil_afajdfddahad
> size : 781437440
> stride : 256
> type : stripe
> status : ok
> subsets: 0
> devs : 2
> spares : 0

Alright :-)

> 
> 
> 
> Some funny things occure tho:
> 
> - After an fdisk I have to reboot to reload the partition table. My guess is
> that this has to do with not calling the hardware directly but using the
> devmapper.

Yes, you need to rerun "dmraid -an;dmraid -ay" in order to activate
mappings for any changed/new partitions.

Of course no partitions should be active while changing them.


> - After an fsck 'df -hP' claims that 129MB is used. My question is; by what?
> It's an empty partition with just the lost+found directory.

If you're refering to an empty filesystem (ie, your one mounted
on /storage/sil-set0), that's filesystem metadata.

Filesystem need to store things like bitmaps, inode tables
and group descriptors which consume space even you haven't stored
any files on the filesystem yet.

> 
> I also keep a log of my dmraid test activities and other stuff related to
> dmraid on my website: http://lilith.cathedrallabs.org/dmraid/

Naming got done this way in order to keep it unique in case you've
got multiple RAID controllers on a system (which is your case).
The names are persistant as well, which prevents you from nasty
name changes leading to eg, filesystems mounted on different mountpoints
after a reboot.

There's of course the option to symlink eg, /dev/mapper/sil* names 
to /dev/ataraid/ entries.

> 
> Another question I have: The ChangeLog et all mention that LSI Logic's
> Megaraid is supported. Does this also include the Megaraid used in Dell
> poweredges and HP DL380s?

Tell me ;-)
Presumably the RAID metadata hasn't changed on those: yes.

> If the answer is yes to this question then I should be able to help out
> testing and trying things for this part aswell.

Please do.

> 
> 
> With kind regards, Patrick

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> Ataraid-list at redhat.com
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-- 

Regards,
Heinz    -- The LVM Guy --

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Heinz Mauelshagen                                 Red Hat GmbH
Consulting Development Engineer                   Am Sonnenhang 11
Cluster and Storage Development                   56242 Marienrachdorf
                                                  Germany
Mauelshagen at RedHat.com                            +49 2626 141200
                                                       FAX 924446
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