# installing on a 80gb SSD, need help aligning partitions, etc



## Jago (Jan 12, 2010)

Hello

For my new server, I've ordered an Intel 80GB X25-M G2 SSD to be used as a system drive. For various reasons, I intent to stick with UFS2 for it (ZFS is going to be used on other disks in the system) and I intend to use GPT partitioning. Can anyone point me to any instructions regarding setting up proper sector sizes, properly aligning partitions to blocks and other such things? Windows 7 and Win2008 R2 both do this automagically, but other OSes seem to require a fair bit of manual work still.


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## johnblue (Jan 12, 2010)

Jago said:
			
		

> Can anyone point me to any instructions regarding setting up proper sector sizes, properly aligning partitions to blocks and other such things?


http://www.daemonforums.org/showthread.php?t=2666


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## Jago (Jan 12, 2010)

johnblue said:
			
		

> http://www.daemonforums.org/showthread.php?t=2666


1) That thread shows how to partition a disk using gpt, which is now deprecated in favor of gpart.
2) It doesn't mention SSDs or partition alignment in any way


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## johnblue (Jan 12, 2010)

Jago said:
			
		

> 1) That thread shows how to partition a disk using gpt, which is now deprecated in favor of gpart.
> 2) It doesn't mention SSDs or partition alignment in any way


Clearly, then, you have some note taking and howto writing to do once you get it all figured out.


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## phoenix (Jan 12, 2010)

There's a big long thread about this on the freebsd-current mailing list.  Search for a thread "File system blocks alignment".  There's a lot of info in there about this subject, although not really any concrete consensus on what to do.    But a good place to start.


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## Jago (Jan 12, 2010)

phoenix said:
			
		

> There's a big long thread about this on the freebsd-current mailing list.  Search for a thread "File system blocks alignment".  There's a lot of info in there about this subject, although not really any concrete consensus on what to do.    But a good place to start.


Reading that discussion, here seems to be the first roadblock:



> There's no requirement that the partitioned area on the disk follows
> the GPT header/table in a packed fashion. You can leave a gap. Thus
> you can have the partitioned area start at sector 64.
> 
> ...


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## volatilevoid (Feb 12, 2010)

Did anybody tried to align the partitions like described in this mailing list post? Doesn't sound too complicated.


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## Jago (Feb 13, 2010)

volatilevoid said:
			
		

> Did anybody tried to align the partitions like described in this mailing list post? Doesn't sound too complicated.


That's actually my post


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## volatilevoid (Feb 13, 2010)

Jago said:
			
		

> That's actually my post


:e

Was it as easy as it sounds? I'd like to go with ZFS.

If I understand your post correctly, I have to put boot on block 34 and swap and root have to start on a block dividable by 2048? I don't think the Intel BIOS (rebranded Award I believe) is so funky so it might be possible to align that as well...


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## Jago (Feb 13, 2010)

volatilevoid said:
			
		

> :e
> 
> Was it as easy as it sounds? I'd like to go with ZFS.
> 
> If I understand your post correctly, I have to put boot on block 34 and swap and root have to start on a block dividable by 2048? I don't think the Intel BIOS (rebranded Award I believe) is so funky so it might be possible to align that as well...


Once you know what the hell it is you are supposed to be doing, yes it's quite trivial, the tough part was getting to that point 

Your partitions needs to start on a block dividable by 2048 and the partition sizes need to be dividable by 2048 as wel.


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