SANs with block level replication?

[Mindflux]

Hello Folks

 

I'm currently looking to purchase two SAN's. I plan to use them for iSCSI/CIFS in conjunction with my VMWare vSphere (free) server. I'd like to move my virtual machine data to the SAN and run those over iSCSI as well as share out a slice of storage with ADS permissions over CIFS. I'd also like to be able to have the SANs provide failover, if one should fail the other picks up. (This requires some multipathing, I assume? I'm not privy to that just yet).

 

The second SAN, all I want it to do is replicate the data of the first SAN (ideally in real time).

 

We're a small business, so unfortunately that means small budget. I got a quote from Dell for two EQL 4000's (totaling something like $42,000). That's probably twice what we'd like to spend.

 

I've also priced out some "White box" SAN's running NexentaCore (Solaris Kernel with Ubuntu userland). By the time I add the blocklevel duplication plugin I start getting into Sun 7110 pricing.

 

 

Would a Sun Storage 7110 allow me to do this? Those are (surprisingly) even more reasonably priced than the EQL SANs' from Dell.

 

I look forward to hearing from you! Thank you for your suggestions.

 

-Ryan

[cookie_monster]

Some people have been discussing these features here http://www.edugeek.net/forums/hardware/32631-sun-storage-7110-a-32.html you might want to post in this thread regarding the 7110 (look about half way down the page).

[dhicks]

I'd also like to be able to have the SANs provide failover, if one should fail the other picks up. (This requires some multipathing, I assume? I'm not privy to that just yet).

 

You want DRBD. It allows block devices to be mirrored accross a network. It works best with a dedicated network link (or two) between the machines.

 

--

David Hicks

[EduTech]

Definitley look at the SUN Unified Storage 7110, Just brought one for us and its the best bit of kit brought in ages! Will get another one soon but not unti we get some more money

 

Best company to talk to about the SUN Stuff is CutterProject, Kmount or Linescanner are on the forums just drop them a PM

 

James.

[Tallwood_6]

Would it most make sense to pony up the extra and go VSphere advanced or enterprise if you plan on storing the VM's on a SAN?

[Mindflux]

Would it most make sense to pony up the extra and go VSphere advanced or enterprise if you plan on storing the VM's on a SAN?

 

Maybe? I'm not sure. You start getting into 3-5k per socket when you go enterprise.

 

I'm just looking for a way to keep my data safe. Presently our RAID6 array on my server box backs up our important (SQL DB) to a small NAS I have nightly. I'm looking to add an additional layer of hardware so that the chance of total loss is pretty much impossible in terms of hardware failure. (save a fire, flood, etc).

[Tallwood_6]

I see where you are comming from, but replicating SAN just seems a little overkill for a small business where the money maybe better spend on a single decent SAN with a good onsite hardware warrenty and RAID level. I mean if you have a flood or fire your gunna lose your severs as well unless you have these spead across buildings? D2D2T might provide prove cheaper than a second SAN as well.

[Mindflux]

I see where you are comming from, but replicating SAN just seems a little overkill for a small business where the money maybe better spend on a single decent SAN with a good onsite hardware warrenty and RAID level. I mean if you have a flood or fire your gunna lose your severs as well unless you have these spead across buildings? D2D2T might provide prove cheaper than a second SAN as well.

 

I am not familiar with D2D2T backup solutions (I'm guessing Tape?). I know 2 SANS is overkill, but when you put things in perspective another 15k (or whatever it is) to add storage resiliency to your network isn't bad. I mean, the things you just -CANNOT- afford to lose have to have a value on them, and a database filled with 10 years worth of client data is certainly one of them.

[matt40k]

RAID, mirroring SAN isn't a backup. If you delete it on one SAN, it gets deleted on the other. Backing up to tape and taking it offsite is still a good option, think about how many companies went under after 9/11 because they only had 1 copy of the data... in the tower.

 

how much data are we talking by the way?

[Mindflux]

RAID, mirroring SAN isn't a backup. If you delete it on one SAN, it gets deleted on the other. Backing up to tape and taking it offsite is still a good option, think about how many companies went under after 9/11 because they only had 1 copy of the data... in the tower.

 

how much data are we talking by the way?

 

Right now, as a whole maybe 1TB. But we plan to go paperless in the next year.

 

I realize RAID and SAN->SAN isn't a backup. I'm wanting data redundancy in case of hardware failures that put the kibosh on whole systems. It's not very LIKELY to happen but I want to have a system in place so if it should ever happen I have recourse.

 

I think I'll read up more on D2D2T. Looks like tape archival may help alleviate some of my worries.

[Tallwood_6]

D2D2T incorporating a decent NAS or storage server with backup exec and some agents and an LTO 4 autoloader will certainly give you much more data resiliency than a replicating SAN. I understand your worries about a SAN being a single point of failure but providing its attached to decent UPS and is using raid 6, 10 or 50 then i wouldn't be to concerned.

[Mindflux]

D2D2T incorporating a decent NAS or storage server with backup exec and some agents and an LTO 4 autoloader will certainly give you much more data resiliency than a replicating SAN. I understand your worries about a SAN being a single point of failure but providing its attached to decent UPS and is using raid 6, 10 or 50 then i wouldn't be to concerned.

 

 

Looks like I need to read up on tape autoloaders then. Thanks!

[mjs_mjs]

Looks like I need to read up on tape autoloaders then. Thanks!

 

we have a sony ATI3 tape loader on a 4GB NAS doing D2D2T. Highly recomend it over mirroring a SAN. the best way to work out if a mirrored san is needed is to ask the following question; does it cost more to replicate the data in real time than if the data were to be offline for a 24hr period. if the answer it that it costs more for the SAN then dont bother with it. monney would be better spent on having a decent back up in place (read D2D2T).

 

to throw more spanners in, if your data/applications are mission critical eg google, then you should be looking at clustering your servers so that if one fails there is a complete reserve waiting to take over. Banks do this. we all do it in schools with medium sized networks (we have 3DC's, 4DNS here)

 

infomation that would be usefull is what the data is, how many users connect concurrently, how many virtual servers and how many actual servers.

 

as you say your small and only have about 1TB of data. worst case senario is that you need to set up a new server off site, and then get all of your data onto it from tape. which would take a few days to complete fully i reckon (depending on tapes and if your willing to work 24hr/day).

 

personally i would look at something like having a smaller array for ''actual'' work (14 160GB drives in 2 raid 6 sets) then a larger array for archives and electronic documents (14 1TB drives in 2 raid 5 sets) then in a room other than your server room, an array made up of say 42 2TB drives in raid 5 sets for backups (daily) , and mirrored to tapes weekly of course. that way you have fast reliable storage for the places that get the beating, large reliable storage for rarely used documents, and large amounts of space for keeping backups.

 

it's late so sorry if i've missed something or repeated someone else.

[Mindflux]

we have a sony ATI3 tape loader on a 4GB NAS doing D2D2T. Highly recomend it over mirroring a SAN. the best way to work out if a mirrored san is needed is to ask the following question; does it cost more to replicate the data in real time than if the data were to be offline for a 24hr period. if the answer it that it costs more for the SAN then dont bother with it. monney would be better spent on having a decent back up in place (read D2D2T).

 

to throw more spanners in, if your data/applications are mission critical eg google, then you should be looking at clustering your servers so that if one fails there is a complete reserve waiting to take over. Banks do this. we all do it in schools with medium sized networks (we have 3DC's, 4DNS here)

 

infomation that would be usefull is what the data is, how many users connect concurrently, how many virtual servers and how many actual servers.

 

as you say your small and only have about 1TB of data. worst case senario is that you need to set up a new server off site, and then get all of your data onto it from tape. which would take a few days to complete fully i reckon (depending on tapes and if your willing to work 24hr/day).

 

personally i would look at something like having a smaller array for ''actual'' work (14 160GB drives in 2 raid 6 sets) then a larger array for archives and electronic documents (14 1TB drives in 2 raid 5 sets) then in a room other than your server room, an array made up of say 42 2TB drives in raid 5 sets for backups (daily) , and mirrored to tapes weekly of course. that way you have fast reliable storage for the places that get the beating, large reliable storage for rarely used documents, and large amounts of space for keeping backups.

 

it's late so sorry if i've missed something or repeated someone else.

 

 

How does your tape drive hook up to the network/server? I see some are SAS, some are SCSI.

 

Do you hook the external SAS/SCSI to a server or the SAN? If it's the server that could prove problematic as I'm running VMWare ESXi and the guests don't have direct access to host hardware.

 

If you hook it to the SAN, I'm assuming you need to use a SAN compatible with the autoloader (I'm eyeing a Quantum Superloader 3?).

[Tallwood_6]

We have a storage server running 2003 storage server which has backup exc 12.5 you install either the normal backup exc agents on your virtual servers (they dont know they are virtual) or if you like some of the VM agents. The Quantum autoloader then connects straight into the storage server via SCSI and is very quick. would highly reccommmend LTO 4 comming from AIT 3 & 4, its much quicker and proving much more reliable and should provide you with plenty of capacity for future growth.

[cookie_monster]

We use the LTO3 version of these SuperLoader 3

 

Oh I see you've already seen that

 

 

then you should be looking at clustering your servers so that if one fails there is a complete reserve waiting to take over. Banks do this. we all do it in schools with medium sized networks (we have 3DC's, 4DNS here)

 

We do???

 

I've never had even close to the budget for that kind of setup, we have next bussiness day (sometimes 4 hour) cover on the servers and a setup that allows us to keep the admin system running with a couple of hours fiddling. We have RAID, redundant PSU's, D2D2T and UPS but not entire redundant servers.

Edited November 17, 2009 by cookie_monster

[Duke]

I wouldn't say we have completely redundant servers, in the sense that Exchange and SQL aren't configured in clusters. However, for services like DNS and DCs, we also have multiple servers. This is as much for load balancing as redundancy.

 

I'll also recommend the Sun S7000 storage platform. We have a 7410 and are looking at clustering two 7410 heads then replicating to a 7310 eventually. As others have said, they do replication and de-duplication is also on the roadmap which will reduce your storage requirements when it's available.

 

I must confess to only scanning this thread, but I'd agree with what Tallwood_6 regarding getting a higher-level version of vSphere to take advantage of vMotion and HA. These are some of the main reasons for going the virtualisation and centralised storage route if redundancy and improved availability are your aims.

 

As far as backup goes, if you were doing snapshots and replicating them to elsewhere on-site then that's kind of a backup solution. However, the best option would probably be D2D2T as others have said, maybe using NDMP to directly do the D2T bit? Depending on what your servers are doing, you may likely also want something that does file-level backups and has agents on the servers, particularly for services like Exchange and SQL where you don't necessarily want to restore a complete server, just a particular mailbox or one database from a specific time. Backup Exec will do this for you, as will several other products.

 

As cookie_monster says, most of us probably don't have anywhere near the disaster recovery plans we'd like, and that like goes for SMBs as well as schools. Virtualisation and decent consolidated storage will resolve a lot of your problems, but only if it's done right.

 

Chris

[mjs_mjs]

How does your tape drive hook up to the network/server? I see some are SAS, some are SCSI.

 

Do you hook the external SAS/SCSI to a server or the SAN? If it's the server that could prove problematic as I'm running VMWare ESXi and the guests don't have direct access to host hardware.

 

If you hook it to the SAN, I'm assuming you need to use a SAN compatible with the autoloader (I'm eyeing a Quantum Superloader 3?).

 

We have servers with agents running on them (software), which connect over IP to our backup server. The backup server is a NAS with 4TB of storage and has the tape drive connected directly to it by SCSI.

 

So if you were using SAN's you could connect via iSCSI, then you would also need an actual host for the D2D2T parts. Idaelly you would want the to tape part somewhere easily accessible on a seperate machine to your VM enviroment.

[mjs_mjs]

We do???

 

I've never had even close to the budget for that kind of setup, we have next bussiness day (sometimes 4 hour) cover on the servers and a setup that allows us to keep the admin system running with a couple of hours fiddling. We have RAID, redundant PSU's, D2D2T and UPS but not entire redundant servers.

 

 

I meant 'we' for AD and DNS are redundant. Sorry for the confusion.

 

We dont have the budget for fully redundant servers ither.

[mjs_mjs]

We have a storage server running 2003 storage server which has backup exc 12.5 you install either the normal backup exc agents on your virtual servers (they dont know they are virtual) or if you like some of the VM agents. The Quantum autoloader then connects straight into the storage server via SCSI and is very quick. would highly reccommmend LTO 4 comming from AIT 3 & 4, its much quicker and proving much more reliable and should provide you with plenty of capacity for future growth.

 

we're looking at moving to LTO, but have inheritited the ATI autoloader and it's ok for now, even tho the tapes are expensive.

[cookie_monster]

We do???

 

I've never had even close to the budget for that kind of setup, we have next bussiness day (sometimes 4 hour) cover on the servers and a setup that allows us to keep the admin system running with a couple of hours fiddling. We have RAID, redundant PSU's, D2D2T and UPS but not entire redundant servers.

 

 

I meant 'we' for AD and DNS are redundant. Sorry for the confusion.

 

We dont have the budget for fully redundant servers ither.

 

 

 

Ah ok, yes multiple DNS/DC's is very good practice.

[Mindflux]

We have a storage server running 2003 storage server which has backup exc 12.5 you install either the normal backup exc agents on your virtual servers (they dont know they are virtual) or if you like some of the VM agents. The Quantum autoloader then connects straight into the storage server via SCSI and is very quick. would highly reccommmend LTO 4 comming from AIT 3 & 4, its much quicker and proving much more reliable and should provide you with plenty of capacity for future growth.

 

 

Yeah I was looking at LTO 4 tapes Thanks for the recommendations.

 

So, even though the SuperLoader has an interface for SAS or SCSI (not iSCSI), you don't have to use it for the backup server? I figured the LAN cable on the SuperLoader was just maybe for management and you had to pull all the data down to the device via SAS or SCSI connectivity. (Though that might be ideal since it would be faster than using Gigabit ethernet.

[cookie_monster]

Our Quantum is connected to our backup exec media server using SCSI and backs up our servers and VMs via remote agents at the moment. As you say the LAN is for management.

[Mindflux]

Our Quantum is connected to our backup exec media server using SCSI and backs up our servers and VMs via remote agents at the moment. As you say the LAN is for management.

 

Ok, hrm that puts a twist on things.

 

If I wanted to do D2D2T and had a superloader 3...

 

I can't just go Server -> SAN (there's my D2D) -> Tape? I guess if the SAN had an os that supported the tape agent and the SAS/SCSI protocol I could.. otherwise I need an intermediate server for this configuration?

[cookie_monster]

Well there's lots of options here really. You can have jobs that run to disk somewhere then back that store up to tape. The Sun 7110 and others support NDMP so you could use a compatible agent to backup the SAN directly. Some people on here are backing up CIFS shares on the 7110 SAN using Backup Exec but I think that's problematic at the moment.

 

If like you say your SAN had a supported agent then you could run a job to backup the SAN to disk then backup to tape from there. We currently just run a backup straight to tape as it doesn't take more than a night to do.