Re: need scratch space

From: Jin Yu <no email>
Date: Tue, 9 Dec 2014 14:29:32 -0600

you are welcome.

you can refer following codes to make a raid 0 volume

#You can list the devices
lsblk
#(RAID 0 only) To create a RAID 0 array, execute the following command
(note the --level=stripe option to stripe the array):
sudo mdadm --create --verbose /dev/md0 --level=stripe
--raid-devices=$number_of_volumes $device_name1 $device_name2
#For example, to create an ext4 file system, execute the following command:
sudo mkfs.ext4 /dev/md0


On Tue, Dec 9, 2014 at 11:42 AM, Jian Feng <freedafeng_at_yahoo.com> wrote:

> Thanks Jennifer and Jin!
>
> You are definitely right. The svdaa is one of the two ssds and it is
> mounted to /mnt. The other ssd (/dev/svdab) is in the list, but not mounted
> to anywhere. I am wondering if there is a way to add the other svdab disk
> to /mnt to make a 37*2 GB disk, (as Jin mentioned). really appreciated your
> help.
>
>
> ------------------------------
> *From:* Jennifer Staab <jstaab_at_cs.unc.edu>
> *To:* Jian Feng <freedafeng_at_yahoo.com>
> *Cc:* "starcluster_at_mit.edu" <starcluster_at_mit.edu>
> *Sent:* Tuesday, December 9, 2014 8:24 AM
> *Subject:* Re: [StarCluster] need scratch space
>
> Submit command "lsblk" and you will see the instance/ephemeral storage.
> In my experience the instance/ephemeral storage will be smaller in size (
> for me 40 GB is typically 37.5/37 GB in size) and usually one disk is
> automatically mounted as "/mnt". Seems like in your case it is likely
> "/dev/xvdaa" is one of the instance/ephemeral disks. If you don't see the
> other with "lsblk" command, it is likely when you created the EC2 you
> forgot to indicate you wanted to use both instance storage disks when you
> added storage to your EC2.
>
> Good Luck.
>
> - Jennifer
>
> On 12/9/14 9:48 AM, Jin Yu wrote:
>
> You can use these two 40G SSD to make a raid0 volume of 80G, and then
> mount it to /scratch.
>
> -Jin
>
> On Mon, Dec 8, 2014 at 1:55 PM, Jian Feng <freedafeng_at_yahoo.com> wrote:
>
> Dear starcluster community,
>
> I created an ec2 cluster using m3.xlarge instance (2*40GB SSD). I did
> not see any scratch space or /scratch folder at all. Here is the disk space
> layout.
>
> root_at_node001:~# df -h
> Filesystem Size Used Avail Use% Mounted on
> /dev/xvda1 20G 5.6G 14G 30% /
> udev 7.4G 8.0K 7.4G 1% /dev
> tmpfs 3.0G 176K 3.0G 1% /run
> none 5.0M 0 5.0M 0% /run/lock
> none 7.4G 0 7.4G 0% /run/shm
> /dev/xvdaa 37G 177M 35G 1% /mnt
> master:/home 20G 5.6G 14G 30% /home
> master:/opt/sge6 20G 5.6G 14G 30% /opt/sge6
>
> In my application, I need a scatch folder on each node that has about
> 50G space. Is there a way to do that? I don't really need /home or
> /opt/sge6 stuff. And I don't run mpi applications.
>
> Maybe I should recreate an AMI?
>
> Thanks!
>
>
>
>
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Received on Tue Dec 09 2014 - 15:29:33 EST