February 8, 2010 at 19:04Entry-level SAN
Continuing the topic of SAN , I want to write about entry-level systems. Suppose we have a small company that has a budget for moving to SAN. Let's see what options there are, what we can get and for what money.
To begin with, we decide - FC or SAS . We assume that we have 3 servers (if you take more, it makes no sense to use SAS), and we need 10 terabytes of space to store the company datadownloaded from torrents .
We need to get the maximum exchange rate, the minimum cost of a megabyte and, ideally, the possibility of expanding the system in the future with minimal budget spending.
First, let's look at solutions on SAS. With sufficient speed (3 gigabits), an acceptable range (8 meters), we get a scalable solution up to ~ 60 Tb in capacity. In this case, we can add another array only by putting additional adapters in the server. Refusing switches, we win for money, but we lose scalability.
Our candidates:
SUN: Sun StorageTek 2530 Array
HP: HP StorageWorks 2000sa G2 Modular Smart Array
IBM: IBM System Storage DS3200
Let's bring the systems into a table and see what we get.
The prices in the table are approximate, taken from the product configurator on the manufacturer’s website. In SUN and IBM, 15k RPM drives, in HP-10k.
We see that, ceteris paribus, HP wins significantly in price and scalability.
I specifically did not take many parameters for comparison, all 3 systems are entry-level, rack-mount, each array consists of a controller module with disks and a shelf with additional disks.
HP wins the price by a wide margin, but in reality everything can go completely different, especially if you hold a competition - the amount is already sufficient to ask for discounts from manufacturers, and how much they throw off depends on the seller. So if you are interested in getting the best price, arrange a tender or bid.
We also need SAS adapters, when choosing them, we need to look at the model of the server in which the adapter is installed - and take the native one, and in the case of self-assembly - it is advisable to take it from the array manufacturer.
In this option, we get a system with 1 scalable array, to which servers are directly connected. If we do not need redundancy, we can connect each server via 1 channel, if redundancy is needed, we will have to use 2 SAS channels.
The system allows us to simply increase the volume, but does not allow us to connect more than N servers, where N is the number of ports in the array. If we want to use 2 or more storage systems, we will havehemorrhoids exciting work on integrating systems with each other so as to optimally use disk space.
And we must remember that when using SAS we are limited to a cable length of 8 meters, therefore, the server and the array will have to be located in one room.
Now let's see what we have for FC.
For now, we’ll select the younger model of the switch, if that is so - additional switches can be added later.
We'll choose between the
Brocade 300 SAN Switch and the Cisco MDS 9124
Comparison Chart :
Switches are similar in almost all respects, with the exception of speed and price. As a rule, Brocade is put in small SANs, they are inexpensive, easy to configure and scale.
Both there and there we can take the basic configuration with 8 ports and then increase it either by adding 8 ports, or by purchasing 1 “long-range” modules per 10 km.
As a rule, if you have 2 sites in your organization - it’s considered good form to put on each pair of switches and connect the sites with 2 links (if you really cancut the loot , it’s possible to make reliability - you can make 4 links).
Let's move on to storage systems.
Since we are dealing with FC, it is worth taking a closer look at EMC products.
What will we choose from?
Sun StorageTek 2540 Array
HP StorageWorks MSA2312fc
IBM System Storage DS3400
EMC CLARiiON AX4
* I did not find the prices for this array on the network, there is only one advertising price, I had to figure it out in parrots. In general, EMC has a very flexible pricing policy; a good big vendor can get a good discount.
Now we can draw conclusions. As usual, HP did everything with its aggressive pricing policy, but we got a dark horse - EMC, which can easily offer a good price and supports VMWare well.
With a budget of $ 40,000, it is quite possible to build an entry-level SAN that will cover the needs of the organization for a couple of years, and later make it possible to freely expand the system.
At the initial stage, we don’t have to think much about the topology of the system, we can freely add both servers and storage systems to the system. With further growth, it is worth thinking about how far the system will grow, think over the topology and distribution of information across storage systems.
When using optics, we are not very limited in distance, when using different converters and cables, the range can be from 85 to 150 meters.
The results.
With a comparable budget, a SAN system gives us more flexibility, speed, scalability and security. If possible, it is better to budget SAN funds.
To begin with, we decide - FC or SAS . We assume that we have 3 servers (if you take more, it makes no sense to use SAS), and we need 10 terabytes of space to store the company data
We need to get the maximum exchange rate, the minimum cost of a megabyte and, ideally, the possibility of expanding the system in the future with minimal budget spending.
First, let's look at solutions on SAS. With sufficient speed (3 gigabits), an acceptable range (8 meters), we get a scalable solution up to ~ 60 Tb in capacity. In this case, we can add another array only by putting additional adapters in the server. Refusing switches, we win for money, but we lose scalability.
Our candidates:
SUN: Sun StorageTek 2530 Array
HP: HP StorageWorks 2000sa G2 Modular Smart Array
IBM: IBM System Storage DS3200
Let's bring the systems into a table and see what we get.
| SUN | HP | Ibm | |
| Number of discs | 48 drives, from 1,500 GB to 96 TB. | 99 SFF discs or 60 LFF discs | 48 hard drives with SAS interface (using three EXP3000 expansion units) |
| Raid | 0, 1, (1 + 0), 3, 5, and 6 (p + q) | 0,1,3,5,6, 10, 50 | RAID-0, -1, -3, -5, -10 |
| Cache | 512 MB / controller, 2 GB / system | 1GB / controller, without battery (capacitors, CompactFlash) | 512MB cache with battery backup and expandability up to 1 GB |
| Controller | 1 or 2 SAS controllers | 2 MSA2300sa G2 maximum | Two active devices |
| Price 10 Tb | ~ $ 40,000 | ~ $ 30,000 | ~ $ 44,000 |
The prices in the table are approximate, taken from the product configurator on the manufacturer’s website. In SUN and IBM, 15k RPM drives, in HP-10k.
We see that, ceteris paribus, HP wins significantly in price and scalability.
I specifically did not take many parameters for comparison, all 3 systems are entry-level, rack-mount, each array consists of a controller module with disks and a shelf with additional disks.
HP wins the price by a wide margin, but in reality everything can go completely different, especially if you hold a competition - the amount is already sufficient to ask for discounts from manufacturers, and how much they throw off depends on the seller. So if you are interested in getting the best price, arrange a tender or bid.
We also need SAS adapters, when choosing them, we need to look at the model of the server in which the adapter is installed - and take the native one, and in the case of self-assembly - it is advisable to take it from the array manufacturer.
In this option, we get a system with 1 scalable array, to which servers are directly connected. If we do not need redundancy, we can connect each server via 1 channel, if redundancy is needed, we will have to use 2 SAS channels.
The system allows us to simply increase the volume, but does not allow us to connect more than N servers, where N is the number of ports in the array. If we want to use 2 or more storage systems, we will have
And we must remember that when using SAS we are limited to a cable length of 8 meters, therefore, the server and the array will have to be located in one room.
Now let's see what we have for FC.
For now, we’ll select the younger model of the switch, if that is so - additional switches can be added later.
We'll choose between the
Brocade 300 SAN Switch and the Cisco MDS 9124
Comparison Chart :
| Brocade 300 SAN switch | Cisco MDS 9124 | |
| Number of ports | 24 | 24 |
| Top speed | 8 gbps | 4 gbps |
| Port licenses | 8 each | 8 each |
| Price | $ 3,500 | $ 5,000 |
Switches are similar in almost all respects, with the exception of speed and price. As a rule, Brocade is put in small SANs, they are inexpensive, easy to configure and scale.
Both there and there we can take the basic configuration with 8 ports and then increase it either by adding 8 ports, or by purchasing 1 “long-range” modules per 10 km.
As a rule, if you have 2 sites in your organization - it’s considered good form to put on each pair of switches and connect the sites with 2 links (if you really can
Let's move on to storage systems.
Since we are dealing with FC, it is worth taking a closer look at EMC products.
What will we choose from?
Sun StorageTek 2540 Array
HP StorageWorks MSA2312fc
IBM System Storage DS3400
EMC CLARiiON AX4
| Sun StorageTek 2540 | HP StorageWorks MSA2312fc | IBM System Storage DS3400 | EMC CLARiiON AX4 | |
| Number of discs | from 5 to 48 - from 730 GB to 48 TB | 99 SFF discs or 60 LFF discs | 48 SAS or SATA (with three EXP3000 expansion shelves) | 4-60 (with expansion pack) |
| Raid | 0, 1, (1 + 0), 3, 5, 6 (p + q) | 0,1,3,5,6, 10, 50 | RAID 0, -1, -3, -5, -6, -10 | RAID 1/0, RAID 3, RAID 5 |
| Cache | 512 MB or 1 GB / controller (up to 2 GB / system) | 1GB Read / Write. ECC with backup to FLASH memory | 512 MB, upgrade to 1 GB | 1 GB of memory per storage processor, up to 2 processors |
| Controller | 1 or 2 controllers, 2-4 FC ports on the controller | 2xFC 4 Gb per controller | 2xFC 4 Gb per controller | 2xFC 4 Gb per controller |
| Price 10 Tb | ~ $ 46,000 | ~ $ 34,000 | ~ $ 46,000 | $ 34,000 * |
* I did not find the prices for this array on the network, there is only one advertising price, I had to figure it out in parrots. In general, EMC has a very flexible pricing policy; a good big vendor can get a good discount.
Now we can draw conclusions. As usual, HP did everything with its aggressive pricing policy, but we got a dark horse - EMC, which can easily offer a good price and supports VMWare well.
With a budget of $ 40,000, it is quite possible to build an entry-level SAN that will cover the needs of the organization for a couple of years, and later make it possible to freely expand the system.
At the initial stage, we don’t have to think much about the topology of the system, we can freely add both servers and storage systems to the system. With further growth, it is worth thinking about how far the system will grow, think over the topology and distribution of information across storage systems.
When using optics, we are not very limited in distance, when using different converters and cables, the range can be from 85 to 150 meters.
The results.
With a comparable budget, a SAN system gives us more flexibility, speed, scalability and security. If possible, it is better to budget SAN funds.