[Lustre-discuss] howto make a lvm, or virtual lvm?

[Eudes PHILIPPE]

Ok, so, i'll try this :
- One mds
- 2 physical oss with one drive (1 GB) (one ost on one oss)

On client, mount mds on /home..
lfs setstripe -c2 /home

I upload (in sftp) one file, 300 MB
- On Oss 1, he use 150 Mb of 1000
- On Oss 2, he use 150 Mb of 1000

All right!

I continue... copy my first file 4 times (so there is 5 * 300 MB = 1500 MB)
- On Oss 1, he use 750 Mb of 1000
- On Oss 2, he use 750 Mb of 1000

*************************
Now, I add a new oss server, with one ost (1GB)
- On Oss 1, he use 750 Mb of 1000
- On Oss 2, he use 750 Mb of 1000
- On Oss 3, he use 0 Mb of 1000

lfs setstripe -c3 /home on client

I upload a big file, 1.3 Go
He write on oss1, 2 and 3, but, when oss 1 and oss2 are full, he stop
(Couldn't write to remote file "/home/big_log.log": Failure)
******************************

So now, 
- On Oss 1, he use 1000 Mb of 1000
- On Oss 2, he use 1000 Mb of 1000
- On Oss 3, he use 250 Mb of 1000
I upload again, just for see, my first file (300 MB), he copy the file only
on Oss3 (oss 1 and 2 are full of course), it's ok :)

Is there a solution for this problem?

Regards



-----Message d'origine-----
De : Andreas Dilger [mailto:andreas.dilger at oracle.com] 
Envoyé : mercredi 15 décembre 2010 22:39
À : Eudes PHILIPPE
Cc : lustre-discuss at lists.lustre.org
Objet : Re: [Lustre-discuss] howto make a lvm, or virtual lvm?

On 2010-12-15, at 10:06, Eudes PHILIPPE wrote:
> At the end, I want (if it's possible), a raid 5 over Ethernet, or, 1
physical raid 5 on each ostX and a big lvm I can extend as I want....

Lustre itself can not do RAID over the network, if that is what you are
looking for...

> For my first test, I upload on client a file (1.8 Go) (each ost have 1 
> Go) The problem, is, when sdb is full, he stop the copy, and don't 
> continue on ost2

If you create your file to be striped over both OSTs, then it should work.

Use "lfs setstripe -c2 /home/newfile" to specify a stripe count of 2.

Cheers, Andreas
--
Andreas Dilger
Lustre Technical Lead
Oracle Corporation Canada Inc.