Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > Then if one fileserver was down (even temporarily), then all > > the other fileservers (all four) would have to queue a > > message about the data and task and some heartbeat between > > fileservers could alert it when back up and then make sure > > that the particular filesystem is properly updated. > > Sounds exactly like RAID except that the disks are in > physically different machines. I wonder if you can set up > software RAID to use NFS mounted drives... h... may be > worth playing with. A network block device would work better, but it's not good enough to lump a bunch of nbds together, since if you do that you still need ONE machine looking after the RAID. i.e. you have a single point of failure. -- Michael Wood [EMAIL PROTECTED]
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > Then if one fileserver was down (even temporarily), then all > > the other fileservers (all four) would have to queue a > > message about the data and task and some heartbeat between > > fileservers could alert it when back up and then make sure > > that the particular filesystem is properly updated. > > Sounds exactly like RAID except that the disks are in > physically different machines. I wonder if you can set up > software RAID to use NFS mounted drives... h... may be > worth playing with. A network block device would work better, but it's not good enough to lump a bunch of nbds together, since if you do that you still need ONE machine looking after the RAID. i.e. you have a single point of failure. -- Michael Wood [EMAIL PROTECTED] -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, 10 Oct 2001, Florian Friesdorf wrote: > On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > > Then if one fileserver was down (even temporarily), then all the other > > > fileservers (all four) would have to queue a message about the data and > > > task and some heartbeat between fileservers could alert it when back up > > > and then make sure that the particular filesystem is properly updated. > > > > > > What do you all think about this? > > > > Sounds exactly like RAID except that the disks are in physically > > different machines. I wonder if you can set up software RAID to use NFS > > mounted drives... h... may be worth playing with. > > No solution, just a direction: > > The Enhanced Network Block Device Linux Kernel Module > "It makes a remote disk on a different machine act as though it were a > local disk on your machine. It looks like a block device on the local > machine where it's typically going to appear as /dev/nda." > "The intended use is for RAID over the net" > http://www.it.uc3m.es/~ptb/nbd/ > > from the Software-RAID-Howto: > "Linux RAID can work on most block devices. It doesn't matter whether > you use IDE or SCSI devices, or a mixture. Some people > have also used the Network Block Device (NBD) with more or less success." RAID is definitely not what you want in this situation. Look at CODA which is a massively buffered network filesystem originally designed to work in disconnected operation, managing reentry etc. the relevant kernel support is in the main 2.4 kernel tree these days. striping coda filesystems together may be possible, but I have never played with it. Brian [EMAIL PROTECTED] "You can't depend on your judgement when your imagination is out of focus." -- Mark Twain
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, Oct 10, 2001 at 08:24:10PM +0200, Florian Friesdorf wrote: > On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > > Then if one fileserver was down (even temporarily), then all the other > > > fileservers (all four) would have to queue a message about the data and > > > task and some heartbeat between fileservers could alert it when back up > > > and then make sure that the particular filesystem is properly updated. > > > > > > What do you all think about this? > > > > Sounds exactly like RAID except that the disks are in physically > > different machines. I wonder if you can set up software RAID to use NFS > > mounted drives... h... may be worth playing with. > > No solution, just a direction: > > The Enhanced Network Block Device Linux Kernel Module > "It makes a remote disk on a different machine act as though it were a > local disk on your machine. It looks like a block device on the local > machine where it's typically going to appear as /dev/nda." > "The intended use is for RAID over the net" > http://www.it.uc3m.es/~ptb/nbd/ > > from the Software-RAID-Howto: > "Linux RAID can work on most block devices. It doesn't matter whether > you use IDE or SCSI devices, or a mixture. Some people > have also used the Network Block Device (NBD) with more or less success." There is a thread on debian-isp "RAID over NBD" 10. AUG 2001 where this is discussed in short. Hirling Endre reports success with drbd. http://sourceforge.net/projects/drbd florian -- Florian Friesdorf <[EMAIL PROTECTED]> OpenPGP key available on public key servers --> Save the future of Open Source <-- -> Online-Petition against Software Patents <- --> http://petition.eurolinux.org <--- pgp2SB7ZQpo2F.pgp Description: PGP signature
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > Then if one fileserver was down (even temporarily), then all the other > > fileservers (all four) would have to queue a message about the data and > > task and some heartbeat between fileservers could alert it when back up > > and then make sure that the particular filesystem is properly updated. > > > > What do you all think about this? > > Sounds exactly like RAID except that the disks are in physically > different machines. I wonder if you can set up software RAID to use NFS > mounted drives... h... may be worth playing with. No solution, just a direction: The Enhanced Network Block Device Linux Kernel Module "It makes a remote disk on a different machine act as though it were a local disk on your machine. It looks like a block device on the local machine where it's typically going to appear as /dev/nda." "The intended use is for RAID over the net" http://www.it.uc3m.es/~ptb/nbd/ from the Software-RAID-Howto: "Linux RAID can work on most block devices. It doesn't matter whether you use IDE or SCSI devices, or a mixture. Some people have also used the Network Block Device (NBD) with more or less success." florian -- Florian Friesdorf <[EMAIL PROTECTED]> OpenPGP key available on public key servers --> Save the future of Open Source <-- -> Online-Petition against Software Patents <- --> http://petition.eurolinux.org <--- pgppq44c2bhHn.pgp Description: PGP signature
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3,imap,imap/ssl))
On Wed, 10 Oct 2001, Florian Friesdorf wrote: > On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > > Then if one fileserver was down (even temporarily), then all the other > > > fileservers (all four) would have to queue a message about the data and > > > task and some heartbeat between fileservers could alert it when back up > > > and then make sure that the particular filesystem is properly updated. > > > > > > What do you all think about this? > > > > Sounds exactly like RAID except that the disks are in physically > > different machines. I wonder if you can set up software RAID to use NFS > > mounted drives... h... may be worth playing with. > > No solution, just a direction: > > The Enhanced Network Block Device Linux Kernel Module > "It makes a remote disk on a different machine act as though it were a > local disk on your machine. It looks like a block device on the local > machine where it's typically going to appear as /dev/nda." > "The intended use is for RAID over the net" > http://www.it.uc3m.es/~ptb/nbd/ > > from the Software-RAID-Howto: > "Linux RAID can work on most block devices. It doesn't matter whether > you use IDE or SCSI devices, or a mixture. Some people > have also used the Network Block Device (NBD) with more or less success." RAID is definitely not what you want in this situation. Look at CODA which is a massively buffered network filesystem originally designed to work in disconnected operation, managing reentry etc. the relevant kernel support is in the main 2.4 kernel tree these days. striping coda filesystems together may be possible, but I have never played with it. Brian [EMAIL PROTECTED] "You can't depend on your judgement when your imagination is out of focus." -- Mark Twain -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, Oct 10, 2001 at 08:24:10PM +0200, Florian Friesdorf wrote: > On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > > Then if one fileserver was down (even temporarily), then all the other > > > fileservers (all four) would have to queue a message about the data and > > > task and some heartbeat between fileservers could alert it when back up > > > and then make sure that the particular filesystem is properly updated. > > > > > > What do you all think about this? > > > > Sounds exactly like RAID except that the disks are in physically > > different machines. I wonder if you can set up software RAID to use NFS > > mounted drives... h... may be worth playing with. > > No solution, just a direction: > > The Enhanced Network Block Device Linux Kernel Module > "It makes a remote disk on a different machine act as though it were a > local disk on your machine. It looks like a block device on the local > machine where it's typically going to appear as /dev/nda." > "The intended use is for RAID over the net" > http://www.it.uc3m.es/~ptb/nbd/ > > from the Software-RAID-Howto: > "Linux RAID can work on most block devices. It doesn't matter whether > you use IDE or SCSI devices, or a mixture. Some people > have also used the Network Block Device (NBD) with more or less success." There is a thread on debian-isp "RAID over NBD" 10. AUG 2001 where this is discussed in short. Hirling Endre reports success with drbd. http://sourceforge.net/projects/drbd florian -- Florian Friesdorf <[EMAIL PROTECTED]> OpenPGP key available on public key servers --> Save the future of Open Source <-- -> Online-Petition against Software Patents <- --> http://petition.eurolinux.org <--- msg04228/pgp0.pgp Description: PGP signature
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, Oct 10, 2001 at 08:31:01AM -0400, Peter Billson wrote: > > Then if one fileserver was down (even temporarily), then all the other > > fileservers (all four) would have to queue a message about the data and > > task and some heartbeat between fileservers could alert it when back up > > and then make sure that the particular filesystem is properly updated. > > > > What do you all think about this? > > Sounds exactly like RAID except that the disks are in physically > different machines. I wonder if you can set up software RAID to use NFS > mounted drives... h... may be worth playing with. No solution, just a direction: The Enhanced Network Block Device Linux Kernel Module "It makes a remote disk on a different machine act as though it were a local disk on your machine. It looks like a block device on the local machine where it's typically going to appear as /dev/nda." "The intended use is for RAID over the net" http://www.it.uc3m.es/~ptb/nbd/ from the Software-RAID-Howto: "Linux RAID can work on most block devices. It doesn't matter whether you use IDE or SCSI devices, or a mixture. Some people have also used the Network Block Device (NBD) with more or less success." florian -- Florian Friesdorf <[EMAIL PROTECTED]> OpenPGP key available on public key servers --> Save the future of Open Source <-- -> Online-Petition against Software Patents <- --> http://petition.eurolinux.org <--- msg04227/pgp0.pgp Description: PGP signature
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
> Then if one fileserver was down (even temporarily), then all the other > fileservers (all four) would have to queue a message about the data and > task and some heartbeat between fileservers could alert it when back up > and then make sure that the particular filesystem is properly updated. > > What do you all think about this? Sounds exactly like RAID except that the disks are in physically different machines. I wonder if you can set up software RAID to use NFS mounted drives... h... may be worth playing with. Pete -- http://www.elbnet.com ELB Internet Services, Inc. Web Design, Computer Consulting, Internet Hosting
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap, imap/ssl))
JCR> On Wed, 10 Oct 2001, Saku Ytti wrote: >> We are looking replacement for SunCluster (2*e450) mail server and would >> preferally like to do it with x86/linux cluster software can be commercial >> or free. >> >> What software are currently used to build these? Requirment is that >> the media is replicated and locking functions properly so we can pop >> machines in/out and all user accounts/all mail still works only if >> one server is pop out load on other machines just increses slightly. >> >> There can't be any SPOF. JCR> This "single point of failure" made me wonder... is there such thing as a JCR> network filesystem that can simultaneously write to two (or more) remote JCR> servers? AFAIK Corba provides such capability. It can be configured to store data on several phisical server (with replication of data). Another possible alternatives are Intermezzo and GFS. -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | Ilya Martynov (http://martynov.org/)| | GnuPG 1024D/323BDEE6 D7F7 561E 4C1D 8A15 8E80 E4AE BE1A 53EB 323B DEE6 | | AGAVA Software Company (http://www.agava.com/) | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
> Then if one fileserver was down (even temporarily), then all the other > fileservers (all four) would have to queue a message about the data and > task and some heartbeat between fileservers could alert it when back up > and then make sure that the particular filesystem is properly updated. > > What do you all think about this? Sounds exactly like RAID except that the disks are in physically different machines. I wonder if you can set up software RAID to use NFS mounted drives... h... may be worth playing with. Pete -- http://www.elbnet.com ELB Internet Services, Inc. Web Design, Computer Consulting, Internet Hosting -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
duplicate network filesystems (was: HA mailserver (smtp, pop3, imap, imap/ssl))
On Wed, 10 Oct 2001, Saku Ytti wrote: > We are looking replacement for SunCluster (2*e450) mail server and would > preferally like to do it with x86/linux cluster software can be commercial > or free. > > What software are currently used to build these? Requirment is that > the media is replicated and locking functions properly so we can pop > machines in/out and all user accounts/all mail still works only if > one server is pop out load on other machines just increses slightly. > > There can't be any SPOF. This "single point of failure" made me wonder... is there such thing as a network filesystem that can simultaneously write to two (or more) remote servers? For example, a write(2) or fprintf(3) to a file wouldn't be successful unless it was succesfully written to two (or more selected) remote fileservers. Anything like that? (Hopefully open source.) Can any NFS or SMB/CIFS versions/protocols support that? Maybe this special network filesystem could be configured, for example, to have five remote fileservers. Every data written to this mounted filesystem would have to successfully write to all these filservers. Then when reading, it could just grab from any. Then if one fileserver was down (even temporarily), then all the other fileservers (all four) would have to queue a message about the data and task and some heartbeat between fileservers could alert it when back up and then make sure that the particular filesystem is properly updated. What do you all think about this? Thanks, Jeremy C. Reed ... ISP-FAQ.com -- find answers to your questions http://www.isp-faq.com/
Re: duplicate network filesystems (was: HA mailserver (smtp, pop3, imap, imap/ssl))
JCR> On Wed, 10 Oct 2001, Saku Ytti wrote: >> We are looking replacement for SunCluster (2*e450) mail server and would >> preferally like to do it with x86/linux cluster software can be commercial >> or free. >> >> What software are currently used to build these? Requirment is that >> the media is replicated and locking functions properly so we can pop >> machines in/out and all user accounts/all mail still works only if >> one server is pop out load on other machines just increses slightly. >> >> There can't be any SPOF. JCR> This "single point of failure" made me wonder... is there such thing as a JCR> network filesystem that can simultaneously write to two (or more) remote JCR> servers? AFAIK Corba provides such capability. It can be configured to store data on several phisical server (with replication of data). Another possible alternatives are Intermezzo and GFS. -- -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- | Ilya Martynov (http://martynov.org/)| | GnuPG 1024D/323BDEE6 D7F7 561E 4C1D 8A15 8E80 E4AE BE1A 53EB 323B DEE6 | | AGAVA Software Company (http://www.agava.com/) | -=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=-=- -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
duplicate network filesystems (was: HA mailserver (smtp, pop3, imap,imap/ssl))
On Wed, 10 Oct 2001, Saku Ytti wrote: > We are looking replacement for SunCluster (2*e450) mail server and would > preferally like to do it with x86/linux cluster software can be commercial > or free. > > What software are currently used to build these? Requirment is that > the media is replicated and locking functions properly so we can pop > machines in/out and all user accounts/all mail still works only if > one server is pop out load on other machines just increses slightly. > > There can't be any SPOF. This "single point of failure" made me wonder... is there such thing as a network filesystem that can simultaneously write to two (or more) remote servers? For example, a write(2) or fprintf(3) to a file wouldn't be successful unless it was succesfully written to two (or more selected) remote fileservers. Anything like that? (Hopefully open source.) Can any NFS or SMB/CIFS versions/protocols support that? Maybe this special network filesystem could be configured, for example, to have five remote fileservers. Every data written to this mounted filesystem would have to successfully write to all these filservers. Then when reading, it could just grab from any. Then if one fileserver was down (even temporarily), then all the other fileservers (all four) would have to queue a message about the data and task and some heartbeat between fileservers could alert it when back up and then make sure that the particular filesystem is properly updated. What do you all think about this? Thanks, Jeremy C. Reed ... ISP-FAQ.com -- find answers to your questions http://www.isp-faq.com/ -- To UNSUBSCRIBE, email to [EMAIL PROTECTED] with a subject of "unsubscribe". Trouble? Contact [EMAIL PROTECTED]
