Re: [CentOS] HA Storage Cookbook?

2008-11-10 Thread Jed Reynolds

Les Mikesell wrote:
But, I think the OP's real problem is that everything is tied to one 
single large drive (i.e. the software mirroring is mostly irrelevant as

...

I think that Les makes a good point, and I'd like to push the point even 
more generally: providing network file storage, via SAN or NFS is that 
when you have a single service instance, you need procedures and/or 
layers of caching to deal with outages.


I've been using a DRBD cluster joined by a bonded GigE switch and it 
replicates quite quickly. My issues have been related to Heartbeat and 
monitoring. We've learned it's very important to practice and tune the 
fail-over process and detect on file system performance rather than 
merely pinging. Also, it's necessary to monitor application performance 
to see if your storage nodes are suffering load issues. I've seen a 
two-core nfs server perform reliably under load 6-7 but it starts to get 
unhappy at any higher load.


Ironically, we've had absolutely no hard drive errors yet. Hardware 
things that come to mind are: mother boards: I've had more mother board 
and ram failures than drive failures with the systems we've had. Raid 
cards: we've had to swap out 2 3Ware raid controllers also.


Network failures will get you down if you're looking for uptime as well: 
we recently had a nic in one of our storage nodes get into a state where 
it was spouting 60Mbit of bad packets and created quite a layer-2 
networking issue for two cabinets of web servers and two ldap servers. 
When the ldap servers couldn't respond, the access to the storage nodes 
got even worse. It was a black day.


The next thing in our setup has to do with reliance of NFS. NFS may not 
the best choice to put behind web-servers, but it was quickest. We're 
adjusting our application to caching the data found on NFS nodes on 
local file-systems so that we can handle an NFS outage.


My take is: if you're a competent Linux admin, DRBD will cost you less 
with by using appropriate servers be more maintainable than an 
appliance. The challenge of course is working out how to reduce response 
time when any hardware goes sour.



Good luck

Jed
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Re: [CentOS] HA Storage Cookbook?

2008-11-08 Thread Rudi Ahlers
On Fri, Nov 7, 2008 at 9:03 PM, Les Mikesell <[EMAIL PROTECTED]> wrote:
> Gordon McLellan wrote:
>>
>> Les,
>>
>> That's pretty much my problem.  I was hoping to kill two birds with
>> one stone here.  First order of business is to replace the single
>> drive with a raid array.  Second order was to replace a single iscsi
>> server with duo of machines.  If one machine had some sort of
>> non-recoverable problem, the other could pick-up the torch and carry
>> on, even if that means I need to "flip a switch" to make it happen.
>>
>
> My solution for semi-critical stuff (i.e. a few minutes of downtime won't
> cost the 6 figures it would take to prevent it) has been to use RAID1 in a
> chassis with hot-swap carriers and keep a spare chassis handy.  That way the
> common case of a disk failure doesn't even cause a slowdown and you can
> rebuild at an off-peak time without shutting down and in the much less
> likely case of a motherboard failure you yank the drives, put them in the
> other box and reboot.  But, that means you are probably limited to 6 disks
> total with half used as mirrors and you still need backups for software or
> site disasters.
>
> The next step up from this would be DRBD to keep hot copies on the spare
> machine but I've always gotten away with one spare chassis for several
> active servers (and sometime using it for testing other things too...).
>
> You do need to know about the NIC hardware address in
> /etc/sysconfig/ifcfg-eth? when swapping disks around, though.
>
> --
>  Les Mikesell
>   [EMAIL PROTECTED]
> ___


I've been contemplating a setup similar to what you're referring to.

Basically, take two PC's, (say a Dell PE 860 - I got some of these),
and then network-RAID the two PC's, and setup them up with HA to offer
one single IP to the network.

Thus, if either one of them fails, you still have the other one left.

If space (i.e. rackspace) is a problem, then 2x1U's won't cost that
much, and they can take 2 HDD's each, so you could seup RAID 1
(mirror) on the 2 HDD's as well.

If you can afford 2U space, then you can setup a 2950 with 6 drives
each, which has more capacity, and the 2 servers clustered will give
redundancy.

Has anyone done something like this? What was your experience with
this? I know SuperMicro has a chassis that can take 2x small factor
motherboards, which means you can setup something like this on the
same chassis.


-- 

Kind Regards
Rudi Ahlers
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread John R Pierce

Joshua Baker-LePain wrote:
While SATA and SAS are *supposed* to be able to be mixed freely, my 
vendor has warned me that it doesn't always work out that well.  They 
have seen compatibility issues using SATA drives on SAS controllers.  
So for applications where you want/need a SAS controller but still 
need big capacity, these are the drives they recommend.



What I've seen in multiple vendors configuration guidelines is that a 
given SAS controller and SAS/SATA chassis will support SATA *or* SAS, 
but not both at once on the same SAS multiplexor.





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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Joshua Baker-LePain

On Fri, 7 Nov 2008 at 4:22pm, nate wrote


Joshua Baker-LePain wrote:


While SATA and SAS are *supposed* to be able to be mixed freely, my vendor
has warned me that it doesn't always work out that well.  They have seen
compatibility issues using SATA drives on SAS controllers.  So for
applications where you want/need a SAS controller but still need big
capacity, these are the drives they recommend.


Sounds like you need a better vendor for a solution that will
work.



Wait, what?  They steer me away from squirrely configs and find me one 
that works within my budget, and you're criticizing them?  I'm rather 
confused.


Don't try to explain, though.  I don't think I'll get it.

--
Joshua Baker-LePain
QB3 Shared Cluster Sysadmin
UCSF
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread nate
thad wrote:

> HP-EVA controller runs on WIN2K, and you have all the inherent problems of
> why we are staying away from winbloze...  ssu scripting is a pain in the
> neck

On the topic of enterprise storage arrays I'm pretty excited
today I'm having a 150TB 3PAR T400 virtualized storage array
being installed. All on SATA->FC. Controllers can push 100k
IOPS to disk, 2.8Gigabytes/second throughput. Bad ass.

They run a hardened version of Debian. Don't get me wrong it's
not cheap, list price is about $1 million, half of which is
software. Worth every penny(after discount at least). Blows
just about everything else on the market away.

nate

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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread nate
Joshua Baker-LePain wrote:

> While SATA and SAS are *supposed* to be able to be mixed freely, my vendor
> has warned me that it doesn't always work out that well.  They have seen
> compatibility issues using SATA drives on SAS controllers.  So for
> applications where you want/need a SAS controller but still need big
> capacity, these are the drives they recommend.

Sounds like you need a better vendor for a solution that will
work.

nate

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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread thad
>
>
>
> If you have a "real" SAN (HP EVA), you can buy block-level
> replication-software for that.
> But the software is not exactly cheap (six-figure-sum budget expected).
> What does downtime cost for you?



HP-EVA controller runs on WIN2K, and you have all the inherent problems of
why we are staying away from winbloze...  ssu scripting is a pain in the
neck
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Rainer Duffner


Am 07.11.2008 um 23:35 schrieb nate:


Gordon McLellan wrote:


I guess I'm saying, if you interpret the name "Serial Attached Scsi"
literally, then the Seagate ES.2 is not an SAS drive - it is not a
scsi drive with a serial interface.  However, if you interpret SAS as
an interface standard, then the interface board determines what the
drive is, more so than its mechanical construction.


SAS and SATA use the same physical interface, the drive mentioned
is most definitely SATA. Largest SAS drive I have heard of
myself is 400GB, same as the max size for FC drives.



There are also SATA drives with FC-interfaces
"FATA"

Used in SANs, mainly.

Take a look at Promise's VtrakJ610-series for cheap 16-bay JBOD array  
with SAS-connection to the server.

Apple re-badges them...



Rainer



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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Ray Van Dolson
On Fri, Nov 07, 2008 at 05:46:36PM -0500, Joshua Baker-LePain wrote:
> On Fri, 7 Nov 2008 at 2:35pm, nate wrote
>
>> Gordon McLellan wrote:
>>
>>> I guess I'm saying, if you interpret the name "Serial Attached Scsi"
>>> literally, then the Seagate ES.2 is not an SAS drive - it is not a
>>> scsi drive with a serial interface.  However, if you interpret SAS as
>>> an interface standard, then the interface board determines what the
>>> drive is, more so than its mechanical construction.
>>
>> SAS and SATA use the same physical interface, the drive mentioned
>> is most definitely SATA. Largest SAS drive I have heard of
>> myself is 400GB, same as the max size for FC drives.
>
> No.  No it isn't.  It's SAS.  The platters etc are the same hardware used 
> in the SATA part, but the interface circuitry is native SAS.  Note that 
> they offer the drive in both SATA and SAS variants.
>
> While SATA and SAS are *supposed* to be able to be mixed freely, my vendor 
> has warned me that it doesn't always work out that well.  They have seen 
> compatibility issues using SATA drives on SAS controllers.  So for 
> applications where you want/need a SAS controller but still need big 
> capacity, these are the drives they recommend.
>

Hehe, I think the somewhat confusing part about SAS is that you expect
it to be a SCSI disk and have the corresponding performance level, but
that won't necessarily be the case if its got SATA innards. :)

Ray
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Joshua Baker-LePain

On Fri, 7 Nov 2008 at 2:35pm, nate wrote


Gordon McLellan wrote:


I guess I'm saying, if you interpret the name "Serial Attached Scsi"
literally, then the Seagate ES.2 is not an SAS drive - it is not a
scsi drive with a serial interface.  However, if you interpret SAS as
an interface standard, then the interface board determines what the
drive is, more so than its mechanical construction.


SAS and SATA use the same physical interface, the drive mentioned
is most definitely SATA. Largest SAS drive I have heard of
myself is 400GB, same as the max size for FC drives.


No.  No it isn't.  It's SAS.  The platters etc are the same hardware used 
in the SATA part, but the interface circuitry is native SAS.  Note that 
they offer the drive in both SATA and SAS variants.


While SATA and SAS are *supposed* to be able to be mixed freely, my vendor 
has warned me that it doesn't always work out that well.  They have seen 
compatibility issues using SATA drives on SAS controllers.  So for 
applications where you want/need a SAS controller but still need big 
capacity, these are the drives they recommend.


--
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QB3 Shared Cluster Sysadmin
UCSF
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread nate
Gordon McLellan wrote:

> I guess I'm saying, if you interpret the name "Serial Attached Scsi"
> literally, then the Seagate ES.2 is not an SAS drive - it is not a
> scsi drive with a serial interface.  However, if you interpret SAS as
> an interface standard, then the interface board determines what the
> drive is, more so than its mechanical construction.

SAS and SATA use the same physical interface, the drive mentioned
is most definitely SATA. Largest SAS drive I have heard of
myself is 400GB, same as the max size for FC drives.

nate

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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread nate
Rudi Ahlers wrote:

>> http://www.openfiler.com/products
>>
>> For me I would just buy a real storage array, better reliability
>> generally. Though entry level pricing is around $20k.
> 2x machines to give a network RAID setup. What would you recommend
> using? The idea is to serve to servers which will be clustered as
> well, hosting web hosting Virtual Private Servers.

openfiler(above from my original email) supports clustering in
some form I believe.

I honestly wouldn't trust any such solution myself, if I'm going
the cheap route then I would just have 2 of the systems and back
up the data to the 2nd one on a routine basis. Clustering is a
very in depth, fragile, complex thing to get right, and if not
done very very well can cause much more problems than it helps
prevent.

nate

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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Les Mikesell

Gordon McLellan wrote:

Les,

That's pretty much my problem.  I was hoping to kill two birds with
one stone here.  First order of business is to replace the single
drive with a raid array.  Second order was to replace a single iscsi
server with duo of machines.  If one machine had some sort of
non-recoverable problem, the other could pick-up the torch and carry
on, even if that means I need to "flip a switch" to make it happen.



My solution for semi-critical stuff (i.e. a few minutes of downtime 
won't cost the 6 figures it would take to prevent it) has been to use 
RAID1 in a chassis with hot-swap carriers and keep a spare chassis 
handy.  That way the common case of a disk failure doesn't even cause a 
slowdown and you can rebuild at an off-peak time without shutting down 
and in the much less likely case of a motherboard failure you yank the 
drives, put them in the other box and reboot.  But, that means you are 
probably limited to 6 disks total with half used as mirrors and you 
still need backups for software or site disasters.


The next step up from this would be DRBD to keep hot copies on the spare 
machine but I've always gotten away with one spare chassis for several 
active servers (and sometime using it for testing other things too...).


You do need to know about the NIC hardware address in 
/etc/sysconfig/ifcfg-eth? when swapping disks around, though.


--
  Les Mikesell
   [EMAIL PROTECTED]
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread John R Pierce

Jerry Franz wrote:

Indeed. They're not SAS either.
From the manufacturer's page: "Barracuda ES.2 SAS 3.0-Gb/s 1-TB Hard 
Drive"


Sure sounds like SAS to me. What leads you to believe they are not 
being truthful?





its a typo on that page, probably.

http://www.seagate.com/www/en-us/products/servers/barracuda_es/barracuda_es.2/

says those drives are available both SATA (xxxNS part numbers) and SAS 
(xxxSS p/n's).



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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Gordon McLellan
Reading the datasheet, my interpretation is Seagate has taken a ide
drive chassis (7200rpm, PMR, slow seek times, etc) and added a SAS
interface board.  They mention the sas version offers improved
performance over the sata version, and also the sas version supports a
dual-port interface.  Other more expensive SAS drives take a scsi
drive chassis (10-15krpm, GMR, fast seek times) and add the SAS
interface board.

I guess I'm saying, if you interpret the name "Serial Attached Scsi"
literally, then the Seagate ES.2 is not an SAS drive - it is not a
scsi drive with a serial interface.  However, if you interpret SAS as
an interface standard, then the interface board determines what the
drive is, more so than its mechanical construction.

-Gordon

On Fri, Nov 7, 2008 at 12:16 PM, Jerry Franz <[EMAIL PROTECTED]> wrote:
> Steve Thompson wrote:
>>
>> On Fri, 7 Nov 2008, Gordon McLellan wrote:
>>
>>> I meant SAS; specifically Seagate Barracuda ES.2 drives.  Here's a
>>> tiny version of their huge url:
>>>
>>> http://tiny.cc/3X9fI
>>>
>>> No, they are not the super fast and expensive 15krpm database drives.
>>
>> Indeed. They're not SAS either.
>
> From the manufacturer's page: "Barracuda ES.2 SAS 3.0-Gb/s 1-TB Hard Drive"
>
> Sure sounds like SAS to me. What leads you to believe they are not being
> truthful?
>
> --
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Rainer Duffner
Gordon McLellan schrieb:
> Les,
>
> That's pretty much my problem.  I was hoping to kill two birds with
> one stone here.  First order of business is to replace the single
> drive with a raid array.  Second order was to replace a single iscsi
> server with duo of machines.  If one machine had some sort of
> non-recoverable problem, the other could pick-up the torch and carry
> on, even if that means I need to "flip a switch" to make it happen.
>
> Gordon
>   

Well, you can always have spare HW onsite.
Unless we are talking about a colo-situation, that's usually the way to
avoid cost and/or headaches.

Because even the high-end solutions are not really trouble-free


Rainer
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Gordon McLellan
Les,

That's pretty much my problem.  I was hoping to kill two birds with
one stone here.  First order of business is to replace the single
drive with a raid array.  Second order was to replace a single iscsi
server with duo of machines.  If one machine had some sort of
non-recoverable problem, the other could pick-up the torch and carry
on, even if that means I need to "flip a switch" to make it happen.

Gordon





On Fri, Nov 7, 2008 at 11:06 AM, Les Mikesell <[EMAIL PROTECTED]> wrote:

> But, I think the OP's real problem is that everything is tied to one single
> large drive (i.e. the software mirroring is mostly irrelevant as well as the
> controller type).  These would get you a queue of outstanding commands
> compared to a SATA, but if you want a big difference in throughput or less
> latency when multitasking you really have to split things over a bunch of
> drives, either with some other type of raid or explicitly mounting different
> filesystems so you can control which things compete for the disk head
> position.
>
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Jerry Franz

Steve Thompson wrote:

On Fri, 7 Nov 2008, Gordon McLellan wrote:


I meant SAS; specifically Seagate Barracuda ES.2 drives.  Here's a
tiny version of their huge url:

http://tiny.cc/3X9fI

No, they are not the super fast and expensive 15krpm database drives.


Indeed. They're not SAS either.

From the manufacturer's page: "Barracuda ES.2 SAS 3.0-Gb/s 1-TB Hard Drive"

Sure sounds like SAS to me. What leads you to believe they are not being 
truthful?


--
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Steve Thompson

On Fri, 7 Nov 2008, Gordon McLellan wrote:


I meant SAS; specifically Seagate Barracuda ES.2 drives.  Here's a
tiny version of their huge url:

http://tiny.cc/3X9fI

No, they are not the super fast and expensive 15krpm database drives.


Indeed. They're not SAS either.

Steve
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Les Mikesell

Ray Van Dolson wrote:

On Fri, Nov 07, 2008 at 10:49:22AM -0500, Gordon McLellan wrote:

Ray,

I meant SAS; specifically Seagate Barracuda ES.2 drives.  Here's a
tiny version of their huge url:

http://tiny.cc/3X9fI

No, they are not the super fast and expensive 15krpm database drives.

-Gordon


Ah.  So the description says it's a SATA drive, but I guess the
connector is SAS...


It's the same connector except keyed so you can plug a SATA device into 
a SAS backplane but not the reverse.   SAS controllers are required to 
support SATA devices.


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   [EMAIL PROTECTED]




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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Les Mikesell

Gordon McLellan wrote:

Ray,

I meant SAS; specifically Seagate Barracuda ES.2 drives.  Here's a
tiny version of their huge url:

http://tiny.cc/3X9fI

No, they are not the super fast and expensive 15krpm database drives.



But, I think the OP's real problem is that everything is tied to one 
single large drive (i.e. the software mirroring is mostly irrelevant as 
well as the controller type).  These would get you a queue of 
outstanding commands compared to a SATA, but if you want a big 
difference in throughput or less latency when multitasking you really 
have to split things over a bunch of drives, either with some other type 
of raid or explicitly mounting different filesystems so you can control 
which things compete for the disk head position.


--
  Les Mikesell
   [EMAIL PROTECTED]

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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Ray Van Dolson
On Fri, Nov 07, 2008 at 10:49:22AM -0500, Gordon McLellan wrote:
> Ray,
> 
> I meant SAS; specifically Seagate Barracuda ES.2 drives.  Here's a
> tiny version of their huge url:
> 
> http://tiny.cc/3X9fI
> 
> No, they are not the super fast and expensive 15krpm database drives.
> 
> -Gordon

Ah.  So the description says it's a SATA drive, but I guess the
connector is SAS...

Thanks for the link!

> 
> On Fri, Nov 7, 2008 at 10:32 AM, Ray Van Dolson <[EMAIL PROTECTED]> wrote:
> > I'm guessing you mean SATA instead of SAS.
> >
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Gordon McLellan
So the short answers are:

1) centos/redhat possess no built-in means of block-level replication
via GFS / RHCS
2) openfiler provides some manor of block-level replication
3) there's "beta" software out there that can do it, but it might not
be a good idea for production (drbd)

Just for reference; my hardware vendor can set me up with a Supermicro
Superserver with 8tb of SAS disk space on hardware raid, 8g of ram and
a 5410 quad core cpu for about $4500.  From Dell, I can buy an empty
SAN box for about $5000, and then pay $500 ea for 1tb sas disks that I
can buy retail for about $200.  The Dell solution provides no
replication either.  The only thing I see Dell providing in this case
is a brand name and an on-site warranty.  Given the most likely item
to fail in a storage server is going to be the storage, I don't see
the on-site warranty being a big bonus, since they still have to ship
you a new drive.

-Gordon
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Gordon McLellan
Ray,

I meant SAS; specifically Seagate Barracuda ES.2 drives.  Here's a
tiny version of their huge url:

http://tiny.cc/3X9fI

No, they are not the super fast and expensive 15krpm database drives.

-Gordon


On Fri, Nov 7, 2008 at 10:32 AM, Ray Van Dolson <[EMAIL PROTECTED]> wrote:
> I'm guessing you mean SATA instead of SAS.
>
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RE: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Flaherty, Patrick
> >>> Hello List,
> >>>
> >>> Can anyone recommend some sites regarding building 
> high-availability
> >>> storage networks using centos (or the upstream providers 
> brand name)?
> >>> I need to have approx 2-3 tb of storage available via 
> iscsi and smb,
> >>> but worry about having it all on a single server.  Most of the HA
> >>> articles I'm reading deal with application high 
> availability, but not
> >>> storage.
> >>>   
> >> Check out openfiler?
> >>
> >> http://www.openfiler.com/products
> >>
> >> For me I would just buy a real storage array, better reliability
> >> generally. Though entry level pricing is around $20k.
> >
> > In some countries those storage arrays are about 3 more 
> expensive, so
> > it's cheaper to build it yourself with PC / server components. I'm
> > actually interested in such a setup as well, and would like 
> to cluster
> > 2x machines to give a network RAID setup. What would you recommend
> > using? The idea is to serve to servers which will be clustered as
> > well, hosting web hosting Virtual Private Servers.
> >
> 
> You could use DRBD, if you trust it.
> AFAIK, Parallels more-or-less supports this.
> http://wiki.openvz.org/HA_cluster_with_DRBD_and_Heartbeat

I use drbd for database HA for over a year and have never seen any
problems. I'm fairly confident it's ability. I know this is a CentOS
mailing list, but a couple pizza boxes and a sas shelf that allows 2+
connections using open solaris+zfs may be your cheapest bet (if you
trust a single sas box). ZFS lets you export the volumes as iscsi, nfs,
and cifs. You can also use their storagetek suite to replicate over two
boxes with independent storage.

Patrick
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Rainer Duffner
Gordon McLellan schrieb:
> So the short answers are:
>
> 1) centos/redhat possess no built-in means of block-level replication
> via GFS / RHCS
> 2) openfiler provides some manor of block-level replication
> 3) there's "beta" software out there that can do it, but it might not
> be a good idea for production (drbd)
>
> Just for reference; my hardware vendor can set me up with a Supermicro
> Superserver with 8tb of SAS disk space on hardware raid, 8g of ram and
> a 5410 quad core cpu for about $4500.  From Dell, I can buy an empty
> SAN box for about $5000, and then pay $500 ea for 1tb sas disks that I
> can buy retail for about $200.  The Dell solution provides no
> replication either.  The only thing I see Dell providing in this case
> is a brand name and an on-site warranty.  Given the most likely item
> to fail in a storage server is going to be the storage, I don't see
> the on-site warranty being a big bonus, since they still have to ship
> you a new drive.
>
>   

If you have a "real" SAN (HP EVA), you can buy block-level
replication-software for that.
But the software is not exactly cheap (six-figure-sum budget expected).
What does downtime cost for you?

With a SAN, you also need switches and HBAs - and everything redundant

I'd look into ZFS+StorageTek Availability-Suite - or, as sugggested,
scrap the idea entirely and instead go for reliable hardware+onsite
spares + a fast backup (which also means fast restore, usually). If your
tape-backup does 80MB/s and you have 3 TB of data, you need about half a
day to do a full-restore...


cheers,
Rainer
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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Ray Van Dolson
On Fri, Nov 07, 2008 at 10:18:02AM -0500, Gordon McLellan wrote:
> So the short answers are:
> 
> 1) centos/redhat possess no built-in means of block-level replication
> via GFS / RHCS
> 2) openfiler provides some manor of block-level replication
> 3) there's "beta" software out there that can do it, but it might not
> be a good idea for production (drbd)
> 
> Just for reference; my hardware vendor can set me up with a Supermicro
> Superserver with 8tb of SAS disk space on hardware raid, 8g of ram and
> a 5410 quad core cpu for about $4500.  From Dell, I can buy an empty
> SAN box for about $5000, and then pay $500 ea for 1tb sas disks that I
> can buy retail for about $200.  The Dell solution provides no
> replication either.  The only thing I see Dell providing in this case
> is a brand name and an on-site warranty.  Given the most likely item
> to fail in a storage server is going to be the storage, I don't see
> the on-site warranty being a big bonus, since they still have to ship
> you a new drive.

I'm guessing you mean SATA instead of SAS.

I suppose you could perhaps do something with iSCSI or ATAoE to another
similarly configured box and then tie the local corresponding block
device and the ATAoE/iSCSI block device together with RAID1 or LVM...

Don't know how well that'd work vs something drbd with a local, "fast"
device and a remote "slow" device (1Gbps over the network).

Ray
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RE: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Andrew Cotter
-Original Message-
From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf
Of Rainer Duffner
Sent: Friday, November 07, 2008 4:34 AM
To: CentOS mailing list
Subject: Re: [CentOS] HA Storage Cookbook?

Rudi Ahlers schrieb:
> On Thu, Nov 6, 2008 at 9:27 PM, nate <[EMAIL PROTECTED]> wrote:
>   
>> Gordon McLellan wrote:
>> 
>>> Hello List,
>>>
>>> Can anyone recommend some sites regarding building high-availability 
>>> storage networks using centos (or the upstream providers brand name)?
>>> I need to have approx 2-3 tb of storage available via iscsi and smb, 
>>> but worry about having it all on a single server.  Most of the HA 
>>> articles I'm reading deal with application high availability, but 
>>> not storage.
>>>   
>> Check out openfiler?
>>
>> http://www.openfiler.com/products
>>
>> For me I would just buy a real storage array, better reliability 
>> generally. Though entry level pricing is around $20k.
>>
>> nate
>>
>> ___
>> 
>
> Hi Nate,
>
> In some countries those storage arrays are about 3 more expensive, so 
> it's cheaper to build it yourself with PC / server components. I'm 
> actually interested in such a setup as well, and would like to cluster 
> 2x machines to give a network RAID setup. What would you recommend 
> using? The idea is to serve to servers which will be clustered as 
> well, hosting web hosting Virtual Private Servers.
>
>



If you are going the route of building your own systems vs. buying a true
filer you may want to look at something like cleversafe.org.  It is intended
for globally diverse storage, but I don't see why you couldn't put together
a system in-house.  I think the minimum number of systems is 4.

Andrew


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Re: [CentOS] HA Storage Cookbook?

2008-11-07 Thread Rainer Duffner
Rudi Ahlers schrieb:
> On Thu, Nov 6, 2008 at 9:27 PM, nate <[EMAIL PROTECTED]> wrote:
>   
>> Gordon McLellan wrote:
>> 
>>> Hello List,
>>>
>>> Can anyone recommend some sites regarding building high-availability
>>> storage networks using centos (or the upstream providers brand name)?
>>> I need to have approx 2-3 tb of storage available via iscsi and smb,
>>> but worry about having it all on a single server.  Most of the HA
>>> articles I'm reading deal with application high availability, but not
>>> storage.
>>>   
>> Check out openfiler?
>>
>> http://www.openfiler.com/products
>>
>> For me I would just buy a real storage array, better reliability
>> generally. Though entry level pricing is around $20k.
>>
>> nate
>>
>> ___
>> 
>
> Hi Nate,
>
> In some countries those storage arrays are about 3 more expensive, so
> it's cheaper to build it yourself with PC / server components. I'm
> actually interested in such a setup as well, and would like to cluster
> 2x machines to give a network RAID setup. What would you recommend
> using? The idea is to serve to servers which will be clustered as
> well, hosting web hosting Virtual Private Servers.
>
>
>
>   

You could use DRBD, if you trust it.
AFAIK, Parallels more-or-less supports this.
http://wiki.openvz.org/HA_cluster_with_DRBD_and_Heartbeat



Rainer



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Re: [CentOS] HA Storage Cookbook?

2008-11-06 Thread Rudi Ahlers
On Thu, Nov 6, 2008 at 9:27 PM, nate <[EMAIL PROTECTED]> wrote:
> Gordon McLellan wrote:
>> Hello List,
>>
>> Can anyone recommend some sites regarding building high-availability
>> storage networks using centos (or the upstream providers brand name)?
>> I need to have approx 2-3 tb of storage available via iscsi and smb,
>> but worry about having it all on a single server.  Most of the HA
>> articles I'm reading deal with application high availability, but not
>> storage.
>
> Check out openfiler?
>
> http://www.openfiler.com/products
>
> For me I would just buy a real storage array, better reliability
> generally. Though entry level pricing is around $20k.
>
> nate
>
> ___

Hi Nate,

In some countries those storage arrays are about 3 more expensive, so
it's cheaper to build it yourself with PC / server components. I'm
actually interested in such a setup as well, and would like to cluster
2x machines to give a network RAID setup. What would you recommend
using? The idea is to serve to servers which will be clustered as
well, hosting web hosting Virtual Private Servers.



-- 

Kind Regards
Rudi Ahlers
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Re: [CentOS] HA Storage Cookbook?

2008-11-06 Thread nate
Gordon McLellan wrote:
> Hello List,
>
> Can anyone recommend some sites regarding building high-availability
> storage networks using centos (or the upstream providers brand name)?
> I need to have approx 2-3 tb of storage available via iscsi and smb,
> but worry about having it all on a single server.  Most of the HA
> articles I'm reading deal with application high availability, but not
> storage.

Check out openfiler?

http://www.openfiler.com/products

For me I would just buy a real storage array, better reliability
generally. Though entry level pricing is around $20k.

nate

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[CentOS] HA Storage Cookbook?

2008-11-06 Thread Gordon McLellan
Hello List,

Can anyone recommend some sites regarding building high-availability
storage networks using centos (or the upstream providers brand name)?
I need to have approx 2-3 tb of storage available via iscsi and smb,
but worry about having it all on a single server.  Most of the HA
articles I'm reading deal with application high availability, but not
storage.

Right now I have a centos 4.6 box serving up a mirrored pair of 1tb
drives via iscsi and smb, but the poor machine comes apart when anyone
tries to write a lot of data.  I'm hopefully to have a little budget
to upgrade in Q1 2009.  Ideally I'd like to get two boxes with proper
hardware raid and have them in a cluster.

Any suggestions are appreciated,

Gordon
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