# Does version 10's installer gracefully handle SSDs?



## horseflesh (Jan 20, 2014)

I know in past versions, you had to manually create partitions in order to properly support SSD sector sizes. Has the version 10 installer been updated to handle that gracefully or do I need to dig up a guide before I install? I suspect the change has not been made as I didn't see a note to that effect in the release documentation. 

The existing solid state disk documentation was updated a couple of months ago, but is kind of behind the times. 

http://www.freebsd.org/doc/en_US.ISO885 ... lid-state/



> Specifically, we will be discussing ATA compatible compact-flash units, which are quite popular as storage media for digital cameras. (...) Other solid state disk solutions do exist, but their expense, obscurity, and relative unease of use places them beyond the scope of this article.



I don't know about you, but I'd feel much more at ease using a modern SSD than a compact flash card, heh.


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## wblock@ (Jan 20, 2014)

I think the disk partitioning is set to align to 4K blocks.  Personally, I set them up myself: Using a Solid State Drive with FreeBSD.


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## horseflesh (Jan 20, 2014)

Great writeup, thanks!


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## ralphbsz (Jan 21, 2014)

Quick note (to add to wblock's fabulous writeup) : To find out whether a SSD supports trim or not, use `camcontrol identify`, and look for the "data set management" (trim) line.  That's much less work than trying to find the documentation for the drive.


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## horseflesh (Jan 21, 2014)

wblock@ said:
			
		

> I think the disk partitioning is set to align to 4K blocks...



Hmm--if anyone on the thread has installed 10 via sysinstall, can you show the output of `gpart show` ? That should put the issue to bed. Or, I'll do that whenever I get around to playing with my 10 system. It seems like a worthy installer upgrade, if it hasn't been done.


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## Beastie (Jan 21, 2014)

horseflesh said:
			
		

> if anyone on the thread has installed 10 via sysinstall


Sorry for nitpicking, but sysinstall has been removed (finally) and replaced with bsdinstall.


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## horseflesh (Jan 21, 2014)

That's not nitpicking, that's kind of important! I read that before and saw that ZFS on the boot volume was supported via bsdinstall, but did not realize bsdinstall replaced sysinstall. 

The handbook says that bsdinstall will "generally" create 4k-aligned partitions if you choose partition sizes in multiples of 1M or 1G.


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## wblock@ (Jan 21, 2014)

No, that means that if the first partition is aligned, alignment will be kept automatically by creating partitions in multiples of 1M or 1G, because both of those are multiples of 4K.


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## horseflesh (Jan 21, 2014)

OK, I see. I guess I will just have to try it and see what happens. 

How can I verify that the installer has or has not partitioned on 4k boundaries--what do I look for in `gpart show`?


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## wblock@ (Jan 21, 2014)

The starting block and size should both be evenly divisible by eight.  For MBR, add the starting block of the FreeBSD partition to the starting block of the MBR slice to get the actual start block of the partition.


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## horseflesh (Jan 21, 2014)

Thanks!


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