Hello, Yesterday, I tried the new Live CD 2.0.5: http://www.cl.cam.ac.uk/Research/SRG/netos/xen/downloads.html One Linux (DebianSarge) + One FreeBSD + One NetBSD I don''t understant what is the ''cow'' setting? I think we should add this to the wiki (and also the manner to integrate FreeBSD and NetBSD): http://wiki.xensource.com CU, Antoine N. _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
> I don''t understant what is the ''cow'' setting? > CU, > Antoine N.Antoine, COW is an acronym for Copy On Write. For booting and running an Operating System, you need a lot of files installed into a partition. If you copy that partition to a file, you have a root partition image. And, if you want to use a number of Xen domains, but your disk space is not enough for the needed root partitions (one for each domain), you can use COW. Just install one only partition, make a root partition image from that to a file, and set it read-only. Now you can set the domain to use it WITH a second file, a COW file, that will be created and mantained by the kernel as a sparse file. Everything you write to the root partition will go, instead, to the COW file. For example, configuration files in the /etc directory. They are really useful, I have a configuration with one host machine with 8 UML virtual machines inside, all of them using only one root partition image, each of them having their exclusive cow file. Yet, I do not know how to use them from Xen. If you are interested, go ahead and ask. -- Bye, Fernando Maciel Souto Maior fernando@araujo.com.br http://www.araujo.com.br +55+31 3270-5886 LPIC/1 # 31908 AVISO------------------------------------------------------------- Esta mensagem pode conter informacao confidencial ou privilegiada. Se voce nao for o destinatario ou a pessoa autorizada a receber esta mensagem, nao pode usar, copiar ou divulgar as informacoes nela contidas ou tomar qualquer acao baseada nessas informacoes. Se voce recebeu esta mensagem por engano, favor avisar o remetente imediatamente, respondendo o e-mail e em seguida apagando-o. Obrigado pela cooperacao. DISCLAIMER-------------------------------------------------------- This message may contain confidential and/or privileged information. If you are not the addressee or authorized to receive this for the addressee, you must not use, copy, disclose or take any action based on any information herein. If you have received this message in error, please advise the sender immediately by replying to this e-mail and delete this message. Thank you for your cooperation. ------------------------------------------------------------------ This email was sent using SquirrelMail - http://squirrelmail.org _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Wed, Apr 06, 2005 at 08:25:04AM -0300, Fernando Maior wrote:> They are really useful, I have a configuration > with one host machine with 8 UML virtual machines > inside, all of them using only one root partition > image, each of them having their exclusive cow file. > > Yet, I do not know how to use them from Xen. If you > are interested, go ahead and ask.UML''s COW facility is a UML-specific implementation. The only general-purpose implementation I know of offhand would be to use LVM''s snapshotting capabilities, but that seems not to be the best-tested part of LVM (or perhaps it''s just that you have problems if it uses all the space you allocated for it). -- I didn''t write a whole, free operating system, either. I wrote some pieces and invited other people to join me by writing other pieces. So I set an example. I said, "I''m going in this direction. Join me and we''ll get there." And enough people joined in that we got there. -- R M Stallman _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users
On Wed, 6 Apr 2005, Martin Maney wrote:> On Wed, Apr 06, 2005 at 08:25:04AM -0300, Fernando Maior wrote: > > They are really useful, I have a configuration > > with one host machine with 8 UML virtual machines > > inside, all of them using only one root partition > > image, each of them having their exclusive cow file. > > > > Yet, I do not know how to use them from Xen. If you > > are interested, go ahead and ask. > > UML''s COW facility is a UML-specific implementation. The only > general-purpose implementation I know of offhand would be to use LVM''s > snapshotting capabilities, but that seems not to be the best-tested > part of LVM (or perhaps it''s just that you have problems if it uses all > the space you allocated for it). >There''s also UnionFS (http://www.linuxjournal.com/article/7714), although I haven''t tried it with Xen yet. Paul _______________________________________________ Xen-users mailing list Xen-users@lists.xensource.com http://lists.xensource.com/xen-users