# Cluster **URL:** \ **Category:** Chatting over the Back Fence\ **Created:** [March 20, 2012, 12:29am UTC](https://forums.suse.com/t/cluster/22382 "2012-03-20T00:29:15Z")\ **Posts on this page:** 11\ **Page:** 1
**Author:** ![System1](https://avatars.discourse-cdn.com/v4/letter/s/51bf81/32.png) [@System1](https://forums.suse.com/u/System1)\ **Post date:** [March 20, 2012, 12:29am UTC](https://forums.suse.com/t/cluster/22382/1 "2012-03-20T00:29:15Z")
Hi, One of my customers suffered a power outage when a branch knocked down a power line and blew up a transformer. The surge took out lots of stuff. Their server lost 2 hard drives and the RAID controller. I’m blaming it on the branch even though I don’t really know what really took them out. They want a 3 node cluster to improve redundancy. This is a hardware question. They don’t want a single point of failure (RAID controller). I believe the easy answer is 3 individual computers. Are there other configurations that will satisfy their need? Blade maybe? They said they lost almost a $1,000.00 and hour. The server went down Tuesday and was finally functional Friday. They are a 24/7 operation. Thanks ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 12:56am UTC](https://forums.suse.com/t/cluster/22382/2 "2012-03-20T00:56:44Z")
On 19.03.2012 23:29, Bob Crandell wrote:[color=blue] > Hi, > > One of my customers suffered a power outage when a branch knocked down a > power line and blew up a transformer. The surge took out lots of stuff. > > Their server lost 2 hard drives and the RAID controller. I’m blaming it > on the branch even though I don’t really know what really took them out. > > They want a 3 node cluster to improve redundancy. This is a hardware > question. They don’t want a single point of failure (RAID controller).[/color] There is no such thing as _no_ single point of failure. In a cluster, no matter how many nodes, it’s the shared storage. Of course, that can be “mirrored” too, but still there’s some SPOF, _somewhere_. Next time, whatver murphy finds, will corrupt the data, which will mirror to all online copies. [color=blue] > They said they lost almost a $1,000.00 and hour. The server went down > Tuesday and was finally functional Friday. They are a 24/7 operation.[/color] They don’t have a single point of failure problem, but a _massive_ disaster recovery problem. Apparently, they have had no (working) DR plan. Three days+ qualifies as “not working”. ## CU, Massimo Rosen Novell Knowledge Partner No emails please! [http://www.cfc-it.de](http://www.cfc-it.de) ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 2:44am UTC](https://forums.suse.com/t/cluster/22382/3 "2012-03-20T02:44:11Z")
On Mon, 19 Mar 2012 22:56:44 +0000, Massimo Rosen wrote: [color=blue] > On 19.03.2012 23:29, Bob Crandell wrote:[color=green] > > > Hi, > > > > One of my customers suffered a power outage when a branch knocked down > > a power line and blew up a transformer. The surge took out lots of > > stuff. > > > > Their server lost 2 hard drives and the RAID controller. I’m blaming > > it on the branch even though I don’t really know what really took them > > out. > > > > They want a 3 node cluster to improve redundancy. This is a hardware > > question. They don’t want a single point of failure (RAID controller).[/color] > > There is no such thing as _no_ single point of failure. In a cluster, no > matter how many nodes, it’s the shared storage. Of course, that can be > “mirrored” too, but still there’s some SPOF, _somewhere_. Next time, > whatver murphy finds, will corrupt the data, which will mirror to all > online copies.[/color] > So a cluster consists of 2 or more computers and shared storage? > (Teaching moment) I thought it could be done that way or each node handle > it’s own copy of the data. Well, that changes things. > [color=blue] > [color=green] > > > They said they lost almost a $1,000.00 and hour. The server went down > > Tuesday and was finally functional Friday. They are a 24/7 operation.[/color] > > They don’t have a single point of failure problem, but a _massive_ > disaster recovery problem. Apparently, they have had no (working) DR > plan. Three days+ qualifies as “not working”.[/color] > This is true. > [color=blue] > > CU,[/color] So if we were to start over from the beginning then it would be better to build a server, clustered or not and take a snap shot once every 6 months to a year and keep replacement parts on hand in case of branches. Yes? No? ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 12:25pm UTC](https://forums.suse.com/t/cluster/22382/4 "2012-03-20T12:25:40Z")
On 20/03/12 00:44, Bob Crandell wrote:[color=blue] > On Mon, 19 Mar 2012 22:56:44 +0000, Massimo Rosen wrote: > [color=green] > > > On 19.03.2012 23:29, Bob Crandell wrote:[color=darkred] > > > > > Hi, > > > > > > One of my customers suffered a power outage when a branch knocked down > > > a power line and blew up a transformer. The surge took out lots of > > > stuff. > > > > > > Their server lost 2 hard drives and the RAID controller. I’m blaming > > > it on the branch even though I don’t really know what really took them > > > out. > > > > > > They want a 3 node cluster to improve redundancy. This is a hardware > > > question. They don’t want a single point of failure (RAID controller).[/color] > > > > There is no such thing as _no_ single point of failure. In a cluster, no > > matter how many nodes, it’s the shared storage. Of course, that can be > > “mirrored” too, but still there’s some SPOF, _somewhere_. Next time, > > whatver murphy finds, will corrupt the data, which will mirror to all > > online copies.[/color] > > So a cluster consists of 2 or more computers and shared storage? > > (Teaching moment) I thought it could be done that way or each node handle > > it’s own copy of the data. Well, that changes things. > > [color=green] > > [color=darkred] > > > > > They said they lost almost a $1,000.00 and hour. The server went down > > > Tuesday and was finally functional Friday. They are a 24/7 operation.[/color] > > > > They don’t have a single point of failure problem, but a _massive_ > > disaster recovery problem. Apparently, they have had no (working) DR > > plan. Three days+ qualifies as “not working”.[/color] > > This is true. > > [color=green] > > > > CU,[/color] > > So if we were to start over from the beginning then it would be better to > build a server, clustered or not and take a snap shot once every 6 months > to a year and keep replacement parts on hand in case of branches. > Yes? No? > [/color] I would have a solution where you have 2 clusters that have mirrored data at SAN level or log shipping if it is a DB. each of the clusters should be in a different racks with separate power supply if in the same datacenter, a different datacenter if possible would be better. you should have to different network paths to the different racks/ datacenters to allow for carrier/ switch/ power failure I agree that they need to have DR plan worked out. Without more info it is difficult to make a call. Lance ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 4:20pm UTC](https://forums.suse.com/t/cluster/22382/5 "2012-03-20T16:20:50Z")
On Tue, 20 Mar 2012 10:25:40 +0000, Lance Haig wrote: [color=blue] > On 20/03/12 00:44, Bob Crandell wrote:[color=green] > > > On Mon, 19 Mar 2012 22:56:44 +0000, Massimo Rosen wrote: > > [color=darkred] > > > > > On 19.03.2012 23:29, Bob Crandell wrote: > > > > > > > Hi,[/color][/color] > > > > SNIP \<[color=green] > > > > So if we were to start over from the beginning then it would be better > > to build a server, clustered or not and take a snap shot once every 6 > > months to a year and keep replacement parts on hand in case of > > branches. Yes? No? > > > > [/color] > > I would have a solution where you have 2 clusters that have mirrored > > data at SAN level or log shipping if it is a DB. each of the clusters > > should be in a different racks with separate power supply if in the same > > datacenter, a different datacenter if possible would be better. > > you should have to different network paths to the different racks/ > datacenters to allow for carrier/ switch/ power failure > > I agree that they need to have DR plan worked out. > > Without more info it is difficult to make a call. > > Lance[/color] At least I have a better understanding of what I think I know. Now I get to see how much they really want to spend. Thanks ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 6:03pm UTC](https://forums.suse.com/t/cluster/22382/6 "2012-03-20T18:03:31Z")
Hi. On 20.03.2012 11:25, Lance Haig wrote:[color=blue] > I would have a solution where you have 2 clusters that have mirrored > data at SAN level or log shipping if it is a DB.[/color] Still a (many!) SPOF. If the data gets corrupted for whatever reason (broken RAID controller, OS running wild, user error), the data is still lost on both sides. ## CU, Massimo Rosen Novell Knowledge Partner No emails please! [http://www.cfc-it.de](http://www.cfc-it.de) ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 7:32pm UTC](https://forums.suse.com/t/cluster/22382/7 "2012-03-20T19:32:46Z")
> They said they lost almost a $1,000.00 and hour. The server went down[color=blue] > Tuesday and was finally functional Friday. They are a 24/7 operation.[/color] Everyone cries the blues when the system goes down, but if you hand them a bill for the amount of services and hardware required to prevent it, they usually quiet down a good bit and find it more as ‘darned inconvenient’ rather than some catastrophic loss. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 10:23pm UTC](https://forums.suse.com/t/cluster/22382/8 "2012-03-20T22:23:46Z")
Bob Crandell wrote: [color=blue] > So if we were to start over from the beginning then it would be > better to build a server, clustered or not and take a snap shot once > every 6 months to a year and keep replacement parts on hand in case > of branches. Yes? No?[/color] It really depends on: 1). How quickly they need to be running 2). How much data they are prepared to loose 3). How much they are willing to spend With virutalisation you can build up some pretty reasonable DR solutions inexpensively to _reduce_ the risk. I’m just wrapping up a DR project and was frankly stunned at what we could achieve for the money we spent. ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 20, 2012, 10:46pm UTC](https://forums.suse.com/t/cluster/22382/9 "2012-03-20T22:46:09Z")
On 20/03/12 16:03, Massimo Rosen wrote:[color=blue] > Hi. > > On 20.03.2012 11:25, Lance Haig wrote:[color=green] > > > I would have a solution where you have 2 clusters that have mirrored > > data at SAN level or log shipping if it is a DB.[/color] > > Still a (many!) SPOF. If the data gets corrupted for whatever reason > (broken RAID controller, OS running wild, user error), the data is still > lost on both sides. > > CU,[/color] Agreed completely. We used to have our db logs shipped over to the second DB server but not imported. so if we had a DB corruption we would be able to import logs upto the corruption and then do the rest manually. It saved my bacon twice. Lance ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 21, 2012, 12:16am UTC](https://forums.suse.com/t/cluster/22382/10 "2012-03-21T00:16:01Z")
Depending on the Hardware involved. You could cluster two of the Servers and use the third as a “Snapshot server” for routine “snaps” of the Clustered Volumes. If you have a SAN in place, even better – Create a Virtual environment as a Pseudo “DR” for the Clustered Servers. Of course you would need some type of replication software and/or a backup solution in place to replicate the Clustered data over to the “DR” site. You could use Operating Systems like SLES10/11 OES2/OES11 for your Virtual “DR” site on your SAN or if a Server is ‘powerful’ enough, that can be used for the ‘muscle’ required to run multiple guests within the host. Leroy Joseph Visual Click Software (eDirectory Management and Reporting) ‘eDirectory Management | DSRAZOR for eDirectory’ ([http://www.visualclick.com/content/dsrazor-for-edirectory.htm](http://www.visualclick.com/content/dsrazor-for-edirectory.htm)) ## – leroyjjr leroyjjr’s Profile: [http://forums.novell.com/member.php?userid=75462](http://forums.novell.com/member.php?userid=75462) View this thread: [http://forums.novell.com/showthread.php?t=453643](http://forums.novell.com/showthread.php?t=453643) ---
**Author:** ![system](https://us1.discourse-cdn.com/flex022/uploads/suse/original/2X/5/5012ba89e3ffb5220dac47d5ea0ba032e2fe1cb6.png) [@system](https://forums.suse.com/u/system)\ **Post date:** [March 21, 2012, 4:54pm UTC](https://forums.suse.com/t/cluster/22382/11 "2012-03-21T16:54:39Z")
On Tue, 20 Mar 2012 17:32:46 +0000, GofBorg wrote: [color=blue][color=green] > > They said they lost almost a $1,000.00 and hour. The server went down > > Tuesday and was finally functional Friday. They are a 24/7 operation.[/color] > > Everyone cries the blues when the system goes down, but if you hand them > a bill for the amount of services and hardware required to prevent it, > they usually quiet down a good bit and find it more as ‘darned > inconvenient’ rather than some catastrophic loss.[/color] Yeah. I offered the advice I’m getting here and haven’t heard a peep. Maybe they are trying to make up for last week.