RE: UBUNTU 9.10 Server Install - LVM problem?
> From: jim.cheet...@gmail.com [mailto:jim.cheet...@gmail.com] On Behalf Of > Sure, but effectively that's what a snapshot is; if a full cold backup > takes say 1 hour, with LVM snapshotting you can reduce that to a > couple of seconds. Surely that's worth investigating? If you can grab > a snapshot that quickly (it'll still take an hour to actually back up > from there, but the DB doesn't have to know), and your production > system can handle being read-only for a second or so, you can dispense > with the need for a replicant in the first place. I think Jim gets where I'm coming from. We don't have the budget for another server for replicant's etc. Any database worth using should be able to put itself quickly in state suitable for applications external to it to take a consistent backup, while remaining online. No one notices a few seconds blocked - we do it hourly for our main production database (IBM IDS/Informix) and no one notices, this with the daytime connections sitting between 30 and 60 most week days. If this linux server does go down, then the users might have to wait an hour or two (or more?) for recovery - that is acceptable to us, as this is only going to be used for moodle to help with industry training. Thanks for all your help and discussion. Regards, Bryce Stenberg. DISCLAIMER: If you have received this email in error, please notify us immediately by reply email, facsimile or collect telephone call to +64 3 9641200 and destroy the original. Please refer to full DISCLAIMER at http://www.hrnz.co.nz/eDisclaimer.htm
Re: UBUNTU 9.10 Server Install - LVM problem?
Call it Disaster/Recovery and then the database or application backup will find its place in the bigger picture. When it comes to databases or applications, it is always a good idea to do a backup of the database or the application files using internal tools (e.g. dump command) before doing a backup at the operating system level such as volume snapshot. This way your databases remain consistent, otherwise whatever transactions not committed to disk are lost and the databases or application structures risk corrupting their integrity. For business continuity in case of unfortunate events, replication is always preferable as first line of defence to a restore from a previous clean backup - less time and work lost. If tuned and configured correctly, the replication mechanism (where available) should have little or no impact on production performance. HTH Adrian On Fri, 2010-03-12 at 18:19 +1300, Jim Cheetham wrote: > On Fri, Mar 12, 2010 at 1:34 PM, Steve Holdoway > wrote: > > I wouldn't do that with the backups personally. If you're after backing > > up important production databases, then I'd look at replicating them > > ( to another machine preferably ) as a frist line of defence. > > Replication gives you defence from hardware failure, the same way that > RAID does. But it has nothing whatsoever to do with being a "backup" > in the data sense. Except ... > > > whilst over there, cold backups have no effect on live systems > > performance... > > The only effect that they have is to push back on your replication > system :-) As long as the primary doesn't get excess load while > waiting for the replicant to come back up, you're in business. > > > and no matter how cumbersome they are, I reckon they > > should always be a part of your backup strategy (: > > Sure, but effectively that's what a snapshot is; if a full cold backup > takes say 1 hour, with LVM snapshotting you can reduce that to a > couple of seconds. Surely that's worth investigating? If you can grab > a snapshot that quickly (it'll still take an hour to actually back up > from there, but the DB doesn't have to know), and your production > system can handle being read-only for a second or so, you can dispense > with the need for a replicant in the first place. > > -jim
Re: UBUNTU 9.10 Server Install - LVM problem?
On Fri, 2010-03-12 at 18:19 +1300, Jim Cheetham wrote: > On Fri, Mar 12, 2010 at 1:34 PM, Steve Holdoway > wrote: > > I wouldn't do that with the backups personally. If you're after backing > > up important production databases, then I'd look at replicating them > > ( to another machine preferably ) as a frist line of defence. > > Replication gives you defence from hardware failure, the same way that > RAID does. But it has nothing whatsoever to do with being a "backup" > in the data sense. Except ... > > > whilst over there, cold backups have no effect on live systems > > performance... > > The only effect that they have is to push back on your replication > system :-) As long as the primary doesn't get excess load while > waiting for the replicant to come back up, you're in business. Well, it just extends the list of changes to be made. No different to adding rows to a table. > > > and no matter how cumbersome they are, I reckon they > > should always be a part of your backup strategy (: > > Sure, but effectively that's what a snapshot is; if a full cold backup > takes say 1 hour, with LVM snapshotting you can reduce that to a > couple of seconds. Surely that's worth investigating? If you can grab > a snapshot that quickly (it'll still take an hour to actually back up > from there, but the DB doesn't have to know), and your production > system can handle being read-only for a second or so, you can dispense > with the need for a replicant in the first place. I disagree. LVM doesn't magically invent performance, which it must do to provide the 'virtual' instant backup you're talking about. The server still suffers. If this isn't a problem, then this is not really relevant. The big difference between this setup and what I'm recommending is that you've moved the whole of your non production oriented services away from the production server, which means that it can do what it needs to - support the live services. The replicated database can then be secured with minimal effect on this database or server. > > -jim
Re: UBUNTU 9.10 Server Install - LVM problem?
On Fri, Mar 12, 2010 at 1:34 PM, Steve Holdoway wrote: > I wouldn't do that with the backups personally. If you're after backing > up important production databases, then I'd look at replicating them > ( to another machine preferably ) as a frist line of defence. Replication gives you defence from hardware failure, the same way that RAID does. But it has nothing whatsoever to do with being a "backup" in the data sense. Except ... > whilst over there, cold backups have no effect on live systems > performance... The only effect that they have is to push back on your replication system :-) As long as the primary doesn't get excess load while waiting for the replicant to come back up, you're in business. > and no matter how cumbersome they are, I reckon they > should always be a part of your backup strategy (: Sure, but effectively that's what a snapshot is; if a full cold backup takes say 1 hour, with LVM snapshotting you can reduce that to a couple of seconds. Surely that's worth investigating? If you can grab a snapshot that quickly (it'll still take an hour to actually back up from there, but the DB doesn't have to know), and your production system can handle being read-only for a second or so, you can dispense with the need for a replicant in the first place. -jim
RE: UBUNTU 9.10 Server Install - LVM problem?
On Fri, 2010-03-12 at 13:25 +1300, Bryce Stenberg wrote: > > I'm using LVM's for there ability to take almost instant 'snapshots' of > volumes to then utilize in full backups of the system including live > databases (after appropriate freezing/blocking of database and flush of > buffers etc to disk ready for snapshot). > > Thanks, Bryce. I wouldn't do that with the backups personally. If you're after backing up important production databases, then I'd look at replicating them ( to another machine preferably ) as a frist line of defence. Also whilst over there, cold backups have no effect on live systems performance... and no matter how cumbersome they are, I reckon they should always be a part of your backup strategy (: Just my $0.02... Steve -- Steve Holdoway http://www.greengecko.co.nz MSN: st...@greengecko.co.nz GPG Fingerprint = B337 828D 03E1 4F11 CB90 853C C8AB AF04 EF68 52E0 signature.asc Description: This is a digitally signed message part
RE: UBUNTU 9.10 Server Install - LVM problem?
> From: Steve Holdoway [mailto:st...@greengecko.co.nz] > Not done this on 9.10, but with all (older) debian'esque services I've > set up with LVM, you need to partition manually, and the options you > need can be hidden off the bottom of the screen, expecially if you're in > text mode. But you can set it all up from this point in the > installation, although it's extremely tedious. > I went and had a harder poke at everything and finally found where it is done - the line it was done from I just thought was some informational text - turned out to be modifiable - Thank you for prodding me to look again :-) > From: jim.cheet...@gmail.com [mailto:jim.cheet...@gmail.com] On Behalf Of > Jim Cheetham > It all sounds much more complex, there's lots of jargon to get used > to, and on a small machine with only a couple of disks that never > change, it's probably too much overhead to be useful. I'm using LVM's for there ability to take almost instant 'snapshots' of volumes to then utilize in full backups of the system including live databases (after appropriate freezing/blocking of database and flush of buffers etc to disk ready for snapshot). Thanks, Bryce. DISCLAIMER: If you have received this email in error, please notify us immediately by reply email, facsimile or collect telephone call to +64 3 9641200 and destroy the original. Please refer to full DISCLAIMER at http://www.hrnz.co.nz/eDisclaimer.htm
Re: UBUNTU 9.10 Server Install - LVM problem?
On Fri, Mar 12, 2010 at 12:34 PM, Steve Holdoway wrote: > > As Jim mentioned, there is loads of jargon with logical and physical > volumes and groups but it does make sense, sorta. It's all based on the > (old?) HP implementation, which is really handy if you used to > administer HP-UX servers (: Good articles on LVM here, I used them when I first set up LVM: http://www.ibm.com/developerworks/linux/library/l-lvm/ http://www.ibm.com/developerworks/library/l-lvm2.html
Re: UBUNTU 9.10 Server Install - LVM problem?
On Fri, 2010-03-12 at 11:41 +1300, Bryce Stenberg wrote: > Hi, > > I've already posed my problem on the UbuntuForums > (http://ubuntuforums.org/showthread.php?t=1426826 ) but thought I'd post > here also as responses are much quicker and I'd like to proceed with > this install before next week... > > I'm installing Ubuntu 9.10 server 64bit on a new machine. > I've manually partitioned the drives so I can use LVM. > I created some logical volumes under LVM. > I think the installer was meant to let me specify file system and mount > point for these volumes but it didn't and I can't see way to make it do > it either. > So I've formatted the logical volumes with ext3 from the command line > but I can't see how to tell the installer that this is where I want the > root file system. > > Does anyone know if there is a command I can run or file to edit that > can tell the installer to now put the root file system on /dev/sda5 (the > logical volume I just formatted) so as the installation can proceed? > > Regards, > Bryce Stenberg. Not done this on 9.10, but with all (older) debian'esque services I've set up with LVM, you need to partition manually, and the options you need can be hidden off the bottom of the screen, expecially if you're in text mode. But you can set it all up from this point in the installation, although it's extremely tedious. As Jim mentioned, there is loads of jargon with logical and physical volumes and groups but it does make sense, sorta. It's all based on the (old?) HP implementation, which is really handy if you used to administer HP-UX servers (: Steve -- Steve Holdoway http://www.greengecko.co.nz MSN: st...@greengecko.co.nz GPG Fingerprint = B337 828D 03E1 4F11 CB90 853C C8AB AF04 EF68 52E0 signature.asc Description: This is a digitally signed message part
Re: UBUNTU 9.10 Server Install - LVM problem?
On Fri, Mar 12, 2010 at 11:41 AM, Bryce Stenberg wrote: > Does anyone know if there is a command I can run or file to edit that > can tell the installer to now put the root file system on /dev/sda5 (the > logical volume I just formatted) so as the installation can proceed? With LVM you don't put any filesystem on a physical partition ... You put LVM "physical volumes" onto partitions, collect sets of PVs into a larger "volume group", and then allocate different "logical volumes" from there. You put your ext3 filesystems onto these logical volumes ... It all sounds much more complex, there's lots of jargon to get used to, and on a small machine with only a couple of disks that never change, it's probably too much overhead to be useful. But, if the disks ever change ... it will save your life, very quickly :-) -jim
UBUNTU 9.10 Server Install - LVM problem?
Hi, I've already posed my problem on the UbuntuForums (http://ubuntuforums.org/showthread.php?t=1426826 ) but thought I'd post here also as responses are much quicker and I'd like to proceed with this install before next week... I'm installing Ubuntu 9.10 server 64bit on a new machine. I've manually partitioned the drives so I can use LVM. I created some logical volumes under LVM. I think the installer was meant to let me specify file system and mount point for these volumes but it didn't and I can't see way to make it do it either. So I've formatted the logical volumes with ext3 from the command line but I can't see how to tell the installer that this is where I want the root file system. Does anyone know if there is a command I can run or file to edit that can tell the installer to now put the root file system on /dev/sda5 (the logical volume I just formatted) so as the installation can proceed? Regards, Bryce Stenberg. DISCLAIMER: If you have received this email in error, please notify us immediately by reply email, facsimile or collect telephone call to +64 3 9641200 and destroy the original. Please refer to full DISCLAIMER at http://www.hrnz.co.nz/eDisclaimer.htm
