# FreeBSD & SSD (Solid State Disks)



## tristan (Dec 28, 2008)

Has anyone here any experience with FreeBSD & solid state disks (ssd's)? I recently read an article on the performance of the Intel SSD's (see http://techreport.com/articles.x/15931/9 ) and that looks very promising.
Are there any mount options I should use to take full advantage of the SSD? (I read that noatime should be used with SSD's, any others?)


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## graudeejs (Dec 28, 2008)

noatime, can be used with any DISK (WELL mediums like CD can't use it)

As i see, it doesn't make difference what kind of technology you use to store data, as long as it's supported by OS.

mount options are not technology specific.

Noatime could be suggested for SSD, because SSD has a limited write times, and if you modify access date, your disk will wear out.
That's why it's suggested to use noatime. Using this will prevent access time modification, and thus SSD will live way longer.


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## oliverh (Dec 28, 2008)

tristan said:
			
		

> Has anyone here any experience with FreeBSD & solid state disks (ssd's)? I recently read an article on the performance of the Intel SSD's (see http://techreport.com/articles.x/15931/9 ) and that looks very promising.
> Are there any mount options I should use to take full advantage of the SSD? (I read that noatime should be used with SSD's, any others?)



You should read this:

http://wiki.eeeuser.com/ssd_write_limit


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## zuborg (Jan 27, 2009)

What about Intel M series SSD ?

They use multi-channel controller and show impressive results for multi-threaded load.

But FreeBSD still don't support NCQ/TCQ for SATA drives so there must be used some scsi-like SATA-controller, as 3ware or LSI go get all performance benefits from these SSD.


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## morbit (Jan 27, 2009)

I was wondering if changing my HD (160GB 7200 from T400) to something like OCZ Solid Series SATA II 2.5" SSD (Unfortunately I have only SATA I controller, so anything faster would be waste of money) would provide me some benefits e.g. faster boot time, less energy used. However, after reading about poor read/write performance of SSD in eee under FreeBSD, I have chosen to stay with linear read 60(Begin)-51(Middle)-31(End) MB/s, buffered read 111 MB/s 

*tested under Windows Server 2008 Datacenter x64


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## softweyr (Jul 21, 2009)

*Learn a bit more about SSDs*

I've been pushed into learning a bit more about current SSD architectures in the past few weeks; we're bringing up a new database server and the powers that be want to run it on SSDs.

There are two competing architectures for SSDs currently, Single Layer Cell and Multi Layer Cell.  The SLC drives are typically "faster", at least on writes, while the MLC drives have much better density and are therefore cheaper.  MLC drives typically use a controller chip that essentially turns the drive into stripe sets in order to speed up the long-ish write cycles, and so the performance can depend much based on the controller.

Current generation MLC drives seem to have quite good write performance, certainly better than garden variety SATA drives.  The SLC drives have astonishing performance, especially in small random read/writes, like say a database server?

So our new database server will use a pair of mirrored MLC drives for the OS and applications, and a pair of mirrored SLC drives for the database.  We haven't decided where to put the database logs yet, perhaps on another MLC drive.

Last night, for grins, I installed FreeBSD 7.2 amd64 on one of the MLC drives.  It took 4 mins 50 secs for the installer to write all of the files to disk, doing a full install of sources, binaries, and X.  That's pretty fast.  make -j 4 buildworld on the clean system took just over 40 minutes, which is a record for me.  This is relatively mundane hardware, Athlon X2 4850e (low-power), 4GB DDR2 ram.

I know I'm replying to an old posting, but wanted to provide up to date information for people searching for FreeBSD and SSD now.

Summary: read some reviews and pick either an SLC device, or an MLC device with a modern controller.  Intel and OCZ both seem to score very well.


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## Djn (Jul 21, 2009)

zuborg said:
			
		

> But FreeBSD still don't support NCQ/TCQ for SATA drives so there must be used some scsi-like SATA-controller, as 3ware or LSI go get all performance benefits from these SSD.




There's a CAM/ATA integration project in 8.0 that supports NCQ and/or TCQ. It seems to be perfectly usable and will be default at some point - if you want to test it, I recommend reading the freebsd-current archives.

The relevant posts are this, which describes the idea, and this, which describes what works and how to test it.


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## User23 (Jul 22, 2009)

There is another thread about SSD in this forum that may interest you: http://forums.freebsd.org/showthread.php?t=1984

greetz


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