Ubuntu-Certification

Feedback on the Dell Inspiron 14z

Asked by Thierry Volpiatto

The last versions of the dell inspiron 14z have two hard drive:
One hitachi 500GB, and One Samsung 32GB.
There is a raid configuration, coupling the 32GB of first drive with the second drive (IIRC)
and (x)ubuntu is unable to detect partitions.
Tested both with alternate CD and desktop CD (64B).

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Jeff Lane 
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Best Jeff Lane  (bladernr) said : 		#1

Hi,

First, the 14z models that are certified do not have the dual drives you mentioned... That being said, we do not certify onboard RAID on consumer level systems because generally, that sort of fake-raid doesn't work well in Linux, if at all.

Personally, if I were you and had that setup anyway, I would remove that RAID setup and reinstall the system. I would put the root filesystem on the 32GB SSD and put /home/, /var/log, /var/cache, /var/run and /tmp on the 500GB drive. By combining that 32GB SSD with a 500GB mechanical drive, you remove any benefit of having SSD to begin with. Look online for partitioning schemes that use both SSD and mechanical hard drives and you'll get a good idea of how they shine.

By putting the static parts of your OS on SSD, you'll improve boot times and response time dramatically. Putting home and the various directories that store frequently written files like /tmp, /var/cache and /var/log on the 500GB disk will also help preserve the lifespan of the SSD.

Anyway, that's just my opinion. If you REALLY insist on RAID, you'll have to undo that onboard RAID setup, Install Ubuntu from the alternate CD and create a Software RAID config that uses both drives. For performance sake, though, I would avoid that and use them as they were designed to be used...

Revision history for this message
Thierry Volpiatto (thierry-volpiatto) said : 		#2

Hi, thanks for your answer.

Jeff Lane <email address hidden> writes:

> Your question #207435 on Ubuntu-Certification changed:
> https://answers.launchpad.net/ubuntu-certification/+question/207435
>
> Status: Open => Answered
>
> Jeff Lane proposed the following answer:
> Hi,
>
> First, the 14z models that are certified do not have the dual drives you
> mentioned... That being said, we do not certify onboard RAID on
> consumer level systems because generally, that sort of fake-raid doesn't
> work well in Linux, if at all.
I finally figure out to install xubuntu on my laptop, the problem was to
start the Livecd, ubuntu or any other Linux, are not able to find the
disks because the Raid and hidden partitions.

So the first thing is to go in the bios setting and change the Hard
drive setting to "Ata" (there is 3 options Ata, Ahci, and "Intel smart
something" which is the same than Ahci).
Then even when this is set, if you go out of bios and start on LiveCd,
it will fail again to find the disks and partitions, the thing to do is
to Save and Go out of Bios WITHOUT trying to start the LiveCd, but just
like if you wanted to start windows.
This will return an error saying the MBR is not found and tell you to
reboot again. From this point you are now able to start Ubuntu LiveCd
or whatever.

Hope that will help other people to install Ubuntu on this machine.
Apart that it works great with ubuntu and I recommend it.

> Personally, if I were you and had that setup anyway, I would remove that
> RAID setup and reinstall the system. I would put the root filesystem on
> the 32GB SSD and put /home/, /var/log, /var/cache, /var/run and /tmp on
> the 500GB drive. By combining that 32GB SSD with a 500GB mechanical
> drive, you remove any benefit of having SSD to begin with. Look online
> for partitioning schemes that use both SSD and mechanical hard drives
> and you'll get a good idea of how they shine.
It is what I did, more or less, though your scheme is better for var/*,
it is a good idea to have the log on the normal Hd.
I have actually:
/ on sdd (32Gb)
/home and /usr on the Hd (500gb)

> By putting the static parts of your OS on SSD, you'll improve boot times
> and response time dramatically.
Yes it is really fast to start.

> Putting home and the various directories that store frequently written
> files like /tmp, /var/cache and /var/log on the 500GB disk will also
> help preserve the lifespan of the SSD.
Agree, the sdd is parking a lot when on battery, I will probably use
the configuration you suggest.

> Anyway, that's just my opinion. If you REALLY insist on RAID, you'll
> have to undo that onboard RAID setup, Install Ubuntu from the alternate
> CD and create a Software RAID config that uses both drives. For
> performance sake, though, I would avoid that and use them as they were
> designed to be used...
Agree.

Thanks.

--
  Thierry
Get my Gnupg key:
gpg --keyserver pgp.mit.edu --recv-keys 59F29997

Revision history for this message
Thierry Volpiatto (thierry-volpiatto) said : 		#3

I finally figure out to install xubuntu on my laptop, the problem was to
start the Livecd, ubuntu or any other Linux, are not able to find the
disks because the Raid and hidden partitions.

So the first thing is to go in the bios setting and change the Hard
drive setting to "Ata" (there is 3 options Ata, Ahci, and "Intel smart
something" which is the same than Ahci).
Then even when this is set, if you go out of bios and start on LiveCd,
it will fail again to find the disks and partitions, the thing to do is
to Save and Go out of Bios WITHOUT trying to start the LiveCd, but just
like if you wanted to start windows.
This will return an error saying the MBR is not found and tell you to
reboot again. From this point you are now able to start Ubuntu LiveCd
or whatever.

Hope that will help other people to install Ubuntu on this machine.
Apart that it works great with ubuntu and I recommend it.