- Aug 19, 2012
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[Cliffsnotes]I'm new to the whole SAN/ZFS thing, and am trying to figure out what I'm doing. I can buy a dirt cheap Dell, a really cheap Sun/Oracle with a SPARC, or a DL380 G6. Which one, and why?[/Cliffsnotes]
For more explanation (possibly too much), continue reading.
So, I'm in the early planning stages of building a "Mini-SAN" (for multiple purposes, one of which being learning what I can about as many aspects of network/server admin/design as I can), and have a question or two. For context, the network will consist of between 3-5 physical hosts (not counting the ZFS box), some (not all) of which will be running a couple of VM's. All hosts will be booting from the SAN. SAN will (eventually) consist of a total of 20 spindles between two disk shelves. Single disk capacity will be low in the interest of cost, and the fact that I don't particularly need a huge amount of storage. (I'm looking at 147GB 10k or 15k SAS drives, I *might* go up to 300GB depending on cost when I purchase, just for the sake of room for future expansion.) Connectivity will be 10Gb (possibly 20Gb, or dual 10Gb port) Infiniband along with standard copper 1GbE.
That all said... In my reading, I'm seeing conflicting reports about the hardware needs of ZFS. Some say CPU doesn't matter much, as long as you have plenty of RAM, and SSD's for L2ARC and ZIL logs. Others say they're seeing 90% usage on 6-core Xeons. Naturally, those reports are met with others saying "You're doing it wrong", but to somebody who has no experience in the area of network storage (that's me), it gets confusing really fast. So, I'm hoping somebody here can help me out. I've more or less narrowed down my search to a handful of options as far as the actual server that will be hosting the ZFS, and I'm hoping I can get some input as to which would be the best choice and why.
First off, I have the opportunity to get a Dell R310 for dirt cheap (way under current eBay pricing). However, the R310 is a fairly low-end box. Single socket, max of 32GB RAM. It's also 1U, which I'm trying to avoid for noise reasons. However, rack space is limited, so there is a slight benefit there. Currently, it's equipped with an i3-540 and 2GB of RAM. Pluses are, it's DDR3, and can be upgraded to at least a 4-core Xeon (I think there's a 6-core option that would work as well, not positive on that) if necessary for performance. Also, by way of being low-end, it would also be low-power. Bonus! It's also a Dell, so I would get the benefit of having hardware from a different vendor to get experience with (other servers will either be HP or Supermicro).
Second option is a Sun/Oracle T5220. Also a single socket, but it's an 8-core SPARC (64 threads total, if that matters for ZFS. I've gotten conflicting reports on that as well). Downside is it's DDR2. Pluses are, supports up to 64GB RAM, it's 2U, and it's not much more expensive than the Dell to get one with 32GB already installed. It would also have the benefit (or downside, depending on how you look at it) of being SPARC, and thus a somewhat unique vendor/hardware architecture. (Possible selling point for a future job)
Last, but not least... HP DL380 G6. Pretty standard on this one. Dual socket, with the possibility of low-power 4 or 6 core Xeons. Supports more (DDR3) RAM (theoretical maximum of 192GB, but I'd probably never get there). Downside, it's about 3x the cost of either of the other options.
I was initially planning on going with the DL380, due to it being newer hardware than the Sun/Oracle, and a "preferred" vendor. Then I checked RAM prices on eBay and realized that currently, DDR2 can be had for cheaper than DDR3 (cost of RAM being a reason for going newer, initially), which got me thinking going with the Sun/Oracle might be "fun" for the unique learning experience. As of yesterday, I got the opportunity to pick up the Dell for even cheaper (though the cost of adding RAM and possibly upgrading to a Xeon would more than make up the difference) than the Sun/Oracle.
So... Now that I've put you to sleep, or made you want to claw your eyes out, or maybe just made you want to smack me... Real question time.
How important is CPU power for a ZFS server? Is ZFS capable of using several threads, or does that not even matter? Is the upgrade from DDR2 to DDR3 worth going with the Dell or HP over the Sun/Oracle? If so, would the single CPU on the Dell be enough for my uses (keeping in mind that the other hosts on the network will have little to no local storage, *everything* will be on the SAN)?
I appreciate any input anyone can give. Sorry if the questions seem a bit stupid or noob-ish... But, I'm a noob, and can't seem to find a source of info that doesn't have somebody else giving conflicting info on the next page. >.>
For more explanation (possibly too much), continue reading.
So, I'm in the early planning stages of building a "Mini-SAN" (for multiple purposes, one of which being learning what I can about as many aspects of network/server admin/design as I can), and have a question or two. For context, the network will consist of between 3-5 physical hosts (not counting the ZFS box), some (not all) of which will be running a couple of VM's. All hosts will be booting from the SAN. SAN will (eventually) consist of a total of 20 spindles between two disk shelves. Single disk capacity will be low in the interest of cost, and the fact that I don't particularly need a huge amount of storage. (I'm looking at 147GB 10k or 15k SAS drives, I *might* go up to 300GB depending on cost when I purchase, just for the sake of room for future expansion.) Connectivity will be 10Gb (possibly 20Gb, or dual 10Gb port) Infiniband along with standard copper 1GbE.
That all said... In my reading, I'm seeing conflicting reports about the hardware needs of ZFS. Some say CPU doesn't matter much, as long as you have plenty of RAM, and SSD's for L2ARC and ZIL logs. Others say they're seeing 90% usage on 6-core Xeons. Naturally, those reports are met with others saying "You're doing it wrong", but to somebody who has no experience in the area of network storage (that's me), it gets confusing really fast. So, I'm hoping somebody here can help me out. I've more or less narrowed down my search to a handful of options as far as the actual server that will be hosting the ZFS, and I'm hoping I can get some input as to which would be the best choice and why.
First off, I have the opportunity to get a Dell R310 for dirt cheap (way under current eBay pricing). However, the R310 is a fairly low-end box. Single socket, max of 32GB RAM. It's also 1U, which I'm trying to avoid for noise reasons. However, rack space is limited, so there is a slight benefit there. Currently, it's equipped with an i3-540 and 2GB of RAM. Pluses are, it's DDR3, and can be upgraded to at least a 4-core Xeon (I think there's a 6-core option that would work as well, not positive on that) if necessary for performance. Also, by way of being low-end, it would also be low-power. Bonus! It's also a Dell, so I would get the benefit of having hardware from a different vendor to get experience with (other servers will either be HP or Supermicro).
Second option is a Sun/Oracle T5220. Also a single socket, but it's an 8-core SPARC (64 threads total, if that matters for ZFS. I've gotten conflicting reports on that as well). Downside is it's DDR2. Pluses are, supports up to 64GB RAM, it's 2U, and it's not much more expensive than the Dell to get one with 32GB already installed. It would also have the benefit (or downside, depending on how you look at it) of being SPARC, and thus a somewhat unique vendor/hardware architecture. (Possible selling point for a future job)
Last, but not least... HP DL380 G6. Pretty standard on this one. Dual socket, with the possibility of low-power 4 or 6 core Xeons. Supports more (DDR3) RAM (theoretical maximum of 192GB, but I'd probably never get there). Downside, it's about 3x the cost of either of the other options.
I was initially planning on going with the DL380, due to it being newer hardware than the Sun/Oracle, and a "preferred" vendor. Then I checked RAM prices on eBay and realized that currently, DDR2 can be had for cheaper than DDR3 (cost of RAM being a reason for going newer, initially), which got me thinking going with the Sun/Oracle might be "fun" for the unique learning experience. As of yesterday, I got the opportunity to pick up the Dell for even cheaper (though the cost of adding RAM and possibly upgrading to a Xeon would more than make up the difference) than the Sun/Oracle.
So... Now that I've put you to sleep, or made you want to claw your eyes out, or maybe just made you want to smack me... Real question time.
How important is CPU power for a ZFS server? Is ZFS capable of using several threads, or does that not even matter? Is the upgrade from DDR2 to DDR3 worth going with the Dell or HP over the Sun/Oracle? If so, would the single CPU on the Dell be enough for my uses (keeping in mind that the other hosts on the network will have little to no local storage, *everything* will be on the SAN)?
I appreciate any input anyone can give. Sorry if the questions seem a bit stupid or noob-ish... But, I'm a noob, and can't seem to find a source of info that doesn't have somebody else giving conflicting info on the next page. >.>