# File system advice for SSD on FreeBSD 9



## jailed (Mar 20, 2012)

Hello,

I'm asking for advice. I'll buy OCZ Vertex 3 SSD for my server.

It will serve FreeBSD Jail + Apache and MySQL.

Which file system should I choose? Is there any installation tricks for SSD and FreeBSD?

I'm already using a Samsung SSD for operating system and jails on FreeBSD 8.2. I'm not sure but I thinks it's running slow. I don't know if it's related with SSD but, When I send the "w" command to the server, it's delaying to show find active users. Since I'm using this old SSD with operating system, I think that there's something wrong with SSD or FreeBSD installation or with UFS. Because, even my desktop computer far slower than the server, with 7200 RPM HDD for operating system is replying my "w" command instantly.

I upgraded one of my servers to FreeBSD 9 and I saw so many differences in my side.

So I need your advice, (if there's) for my issue.

I will use HDD for operating systems and other jails and databases. I will only use this SSD for one jail and MySQL and Apache. I'm hopping for better server performance.

The last question is, should I use AHCI or IDE for best performance and stability? I'm not using AHCI with my SATA SSD drive currently (for any reason but ignorance).

Thanks.


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## cedivad (Mar 20, 2012)

I strongly suggest you Intel SSDs (Intel 320) due to the reliability of these.


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## jailed (Mar 20, 2012)

@cedivad,

I was first interested in Intel SSDs.

In specifications,
80 GB Intel 320 (Write IOPS) = 10.000
60 GB OCZ Vertex 3 (Write IOPS) = 80.000

Why the write IOPS rates are low at Intel? In specification it's noted for 8 GB span. So should I multiply 10 x 10.000 IOPS to compare?


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## cedivad (Mar 20, 2012)

I really don't know it. I have 40 Intel SSD (320/120GB), but *I* don't care if they do 10k or 80k writes per second. As long as they do 1k write/read per second, give me the wonderful SSD latency (<0.1ms) and are reliable, I'm happy with it. So our needs are different, if you need that many writes per second, I can't help you, sorry.

There are the new Intel 520 that are equally priced but better, however *I* would still stand on the 320s, the new version doesn't have the capacitors the 320 has and *might* bring to corruption in case of system crash/power off.

In other words, *I* went with the Intels just because they gave me what *I* wanted, a fast, reliable and cheap drive, *I* don't need anything more =)


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## wblock@ (Mar 20, 2012)

AHCI will give a slight performance increase.  Also make sure that the partitions are aligned to 4K blocks.


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## cedivad (Mar 20, 2012)

wblock@ said:
			
		

> AHCI will give a slight performance increase.  Also make sure that the partitions are aligned to 4K blocks.



Might I ask if you have a howto for that? =)


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## wblock@ (Mar 20, 2012)

AHCI, yes: Moving A FreeBSD System To AHCI.  FreeBSD 9 includes AHCI in the GENERIC kernel.

For alignment, no.  The short version is to use gpart show on the disk in question and see if the partition start sector times 0.125 results in an integer.  Or easier, is an even multiple of 1M or 1G.  SSDs can have larger blocks internally, and it might help speed to align to those larger blocks.  Benchmarking with something rigorous like benchmarks/bonnie++ is the way to scientifically verify it.


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## jailed (Mar 20, 2012)

@cedivad,

My application does writes more than read, however almost %99 of the transaction (both write and read) are made on RAM. So it doesn't need to write or read so much thing from SSD. Because of my ignorance, I thought that IOPS is important.

Now, I agree with you. Data protection is so important. So I should go with Intel 320.

I will deeply investigate about it, but can you tell me all this specifications are available in all Intel 320 series, not depending to storage capacity?

Because I could only found 40 GB and 80 GB options in my country. Or I have to buy from eBay.

Thanks


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## cedivad (Mar 20, 2012)

It might be a paranoia, but if you have a lot of writes check that you aren't going over the write endurance of your drives 
I used the 120GB model because they have the better $/GB ratio. However, if you need less...


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## ondra_knezour (Mar 20, 2012)

Use AHCI, for 4K alignment search forum with 4096 keyword (depends on filesystem you will use), enable TRIM for filesystems on SSD devices.

About OCZ vs. Intel - I have 5+1 Intel 320 on hp P410 RAID controller, getting about 500 MB/s writting. In case you will select extremely fast drives, keep eye on SATA/SAS controller speed, first SATA can do only 300 MB/s. 

There was many problems with SandForce controller used in your selected drives and some Sandy Bridge chipset, check twice if your configuration can be affected.

+ Intel has internal capacitance ensuring write of all data in buffers to NAND in case of power loss
+ Intel has given endurance of writing 5 TB of data on size I'm using (120 GB)

I don't know, if others manufactures have such abilities/data available, worth check.


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