HW recommendation
Hi,
we plan to build ASE server for OLTP application and we need really quick response time ( 100-300 ms). Database will be quite small (less than 2GB) , as well as number of active connections (less than 5). In fact, it will be kind of automatic quotation machine - there's inflow of information about situation on market and we have to react to this situation very quickly. All the logic is in stored procedures.
We have limited budget, so we are limited to Intel.
I have prepared some HW specification:
2 x Xeon 3.2 GHz with 1 MB Level2 cache
2 GB of RAM
SCSI Ultra320 RAID adapter with at least 256 MB cache (preferably 512 MB)
4 x 36 GB 15krpm Ultra320 SCSI disks with 8 MB cache configured as RAID 10 (e.g. strip + mirror)
We will use Red Hat EL 3.0 and ASE 12.5.2 for Linux. I plan to assing 200 MB for tmpfs device for tempdb, 200 MB for OS and remaining RAM (cca 1.6 GB) for ASE.
I think, that it will be quite quick, but I wonder, if it will be as quick as possible with given limits.
So my question is: Is this the optimal setup for small quick OLTP server on Intel architecture ? Would you recommend any changes ? More ( or less ) RAM, disks, cache on RAID adapter ? Quicker disk subsystem ? Different RAM allocations ?
Jan Franek
we plan to build ASE server for OLTP application and we need really quick response time ( 100-300 ms). Database will be quite small (less than 2GB) , as well as number of active connections (less than 5). In fact, it will be kind of automatic quotation machine - there's inflow of information about situation on market and we have to react to this situation very quickly. All the logic is in stored procedures.
We have limited budget, so we are limited to Intel.
I have prepared some HW specification:
2 x Xeon 3.2 GHz with 1 MB Level2 cache
2 GB of RAM
SCSI Ultra320 RAID adapter with at least 256 MB cache (preferably 512 MB)
4 x 36 GB 15krpm Ultra320 SCSI disks with 8 MB cache configured as RAID 10 (e.g. strip + mirror)
We will use Red Hat EL 3.0 and ASE 12.5.2 for Linux. I plan to assing 200 MB for tmpfs device for tempdb, 200 MB for OS and remaining RAM (cca 1.6 GB) for ASE.
I think, that it will be quite quick, but I wonder, if it will be as quick as possible with given limits.
So my question is: Is this the optimal setup for small quick OLTP server on Intel architecture ? Would you recommend any changes ? More ( or less ) RAM, disks, cache on RAID adapter ? Quicker disk subsystem ? Different RAM allocations ?
Jan Franek
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As to RAM, it's relatively inexpensive, and if you underestimate, or if conditions change later, too little RAM can be a major problem.
I've used Serial ATA RAID in a development environment, with occasional huge spikes in activity, with excellent performance, but I wasn't analyzing bottlenecks, so I don't know how the disk I/O compared with the rest of the components.
I've used Serial ATA RAID in a development environment, with occasional huge spikes in activity, with excellent performance, but I wasn't analyzing bottlenecks, so I don't know how the disk I/O compared with the rest of the components.
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One more thing I forgot.
Do not put tape or CD/DVD devices on the Ultra320 SCSI channels. The busses run at the spead of the slowest device on the bus so your very high speed disks will get throttled down if you do.
Bill
Do not put tape or CD/DVD devices on the Ultra320 SCSI channels. The busses run at the spead of the slowest device on the bus so your very high speed disks will get throttled down if you do.
Bill
ASKER
Thank you Bill, your answer look is very valuable, I'll try your suggestions. I have a question about RAID adapter - would you prefer 64 bit / 133 MHz PCI with 256 MB of cache or 64 bit / 66 MHz PCI with 512 MB of cache ?
Good guestion.
During "normal" operation it probably does not make a difference. I am guessing you will see the advantages of the 64x133Mhz adaptor when you do data loads, reporting, backups, etc. Things that are going to require sustained I/O. You have very fast drives on two channels so, in theory ;-) you can use the additional bus bandwidth.
Which adaptors are you considering?
Bill.
During "normal" operation it probably does not make a difference. I am guessing you will see the advantages of the 64x133Mhz adaptor when you do data loads, reporting, backups, etc. Things that are going to require sustained I/O. You have very fast drives on two channels so, in theory ;-) you can use the additional bus bandwidth.
Which adaptors are you considering?
Bill.
ASKER
I have offers from HP (Smart Array 6402 - PCI-X 133 MHz with 256 MB cache), IBM (ServeRAID 6M - PCI-X 133 MHz with 256 MB cache) and ICP Vortex (GDT8x24RZ - PCI-X 66 MHz with 512 MB cache).
O.K., good. You are looking at serious caching controllers.
Take a look at <http://www.tweakers.net/benchdb/test/80>. They have benchmarks on a bunch of different controllers
I would pass on the HP. The benchmarks show it to be no better than half as fast as the LSI MegaRAID. I bet it is more than half the money.
I don't know anything about ICP Vortex and, as such, I would be concerned about the potential support and driver availability issues.
The two I would look at are the IBM ServeRAID 6M W/256MB and the LSI MegaRAID 320 2X with 256MB to the list. The LSI can be configured with 128, 256, or 512MB or cache and the IBM can be bumbed up to 512MB. The IBM comes with battery backup built in and you can get a battery backup option module for the LSI.
I have not found any benchmarks on the IBM so that one is kind of a crap shoot. My recent experiences with IBM have been pretty good as of late and they do build some pretty high performance and scalable x86 servers these days.
The LSI MegaRAID benchmarks best of anything tested on the tweakers site. Driver support is there and they are widley used by folks like Dell. Were it me, I would buy the LSI.
BTW, what server hardware are you looking at? I am curious because so many of the "servers" on the low end come with somekind of RAID controller embedded or as a board option.
Bill
Take a look at <http://www.tweakers.net/benchdb/test/80>. They have benchmarks on a bunch of different controllers
I would pass on the HP. The benchmarks show it to be no better than half as fast as the LSI MegaRAID. I bet it is more than half the money.
I don't know anything about ICP Vortex and, as such, I would be concerned about the potential support and driver availability issues.
The two I would look at are the IBM ServeRAID 6M W/256MB and the LSI MegaRAID 320 2X with 256MB to the list. The LSI can be configured with 128, 256, or 512MB or cache and the IBM can be bumbed up to 512MB. The IBM comes with battery backup built in and you can get a battery backup option module for the LSI.
I have not found any benchmarks on the IBM so that one is kind of a crap shoot. My recent experiences with IBM have been pretty good as of late and they do build some pretty high performance and scalable x86 servers these days.
The LSI MegaRAID benchmarks best of anything tested on the tweakers site. Driver support is there and they are widley used by folks like Dell. Were it me, I would buy the LSI.
BTW, what server hardware are you looking at? I am curious because so many of the "servers" on the low end come with somekind of RAID controller embedded or as a board option.
Bill
ASKER
Hi Bill,
thanks for link, it's interesting even I can't read Dutch (or whatever language it is). It's just pity, they didn't test comparable adaptors - for example test of MegaRaid 320-2x (64bit/133MHz) and MegaRaid 320-2 (64bit/66MHz) with the same cache should show benefit of wider PCI bus. However, from high performance of that 66MHz MegaRaid 320-2 with 256 MB of cache it seems, that the benefit of wider PCI bus is not too big and it's probably the size of the cache that matters more.
According to http://www.adaptec.com/worldwide/company/pressrelease.html?sess=no&prodkey=06112003&language=English+US ICP Vortex is subsidiary of Adapter (and was subsidiary of Intel). I did some research about availability and support of these controllers in Czech Republic. I was warned about problem with LSI support, it seems, they have just distributor here and no local support. ICP Vortex and IBM seem to have no problem with support.
Currently, we have 3 candidates for server HW - IBM xSeries 235, HP Proliant ML370T03 and Dell PowerEdge 2600 - each with 2 x Xeon 3.2 GHz with 1 MB L3 cache, 2 GB of RAM, redundant power supply etc.
OS will be Red Hat Enterprise Linux 3.0 ES and it will be dedicated database server with one of the data processing applications siting right on it and second one will be away (third party SW running only on Windows)
I will do some research about that TOE network adapters.
Thank you for your valuable help.
jano
thanks for link, it's interesting even I can't read Dutch (or whatever language it is). It's just pity, they didn't test comparable adaptors - for example test of MegaRaid 320-2x (64bit/133MHz) and MegaRaid 320-2 (64bit/66MHz) with the same cache should show benefit of wider PCI bus. However, from high performance of that 66MHz MegaRaid 320-2 with 256 MB of cache it seems, that the benefit of wider PCI bus is not too big and it's probably the size of the cache that matters more.
According to http://www.adaptec.com/worldwide/company/pressrelease.html?sess=no&prodkey=06112003&language=English+US ICP Vortex is subsidiary of Adapter (and was subsidiary of Intel). I did some research about availability and support of these controllers in Czech Republic. I was warned about problem with LSI support, it seems, they have just distributor here and no local support. ICP Vortex and IBM seem to have no problem with support.
Currently, we have 3 candidates for server HW - IBM xSeries 235, HP Proliant ML370T03 and Dell PowerEdge 2600 - each with 2 x Xeon 3.2 GHz with 1 MB L3 cache, 2 GB of RAM, redundant power supply etc.
OS will be Red Hat Enterprise Linux 3.0 ES and it will be dedicated database server with one of the data processing applications siting right on it and second one will be away (third party SW running only on Windows)
I will do some research about that TOE network adapters.
Thank you for your valuable help.
jano
FWIW, I would take the IBM xSeries 235 with the IBM RAID adaptor. One source for the products, pre-certified to work together, and one throte to choke if something doesn't work. Also, it is pretty hard to beat IBMs support around the world.
Best of luck,
Bill
Best of luck,
Bill
ASKER
my first estimate was, that active part of database is about 500 MB, so 1.6 GB should be enough for all the caches (data, log, tempdb, procedure), but I'll try to check this estimate.
Do you have some experiance with that Serial ATA RAID ? I took a look at it and I'm afraid of the small cache. I expect, that almost all disk I/O will be caused by log write (or I hope so, because I'd like to keep all the data and tempdb in memory). So, the disk subsystem should be as quick as possible for write operations. And I'm afraid, that small cache will affect this negatively. I'm aware, that writing log through cache is quite dangerous, but the cache on RAID adapter will be backed-up by it's own battery.