Re: (SOLVED) Re: installing FreeBSD 8 on SSDs and UFS2 - partition alignment, block sizes, what does one need to know?

2010-01-17 Thread Ronald Klop
On Fri, 15 Jan 2010 17:57:03 +0100, Dan Naumov dan.nau...@gmail.com  
wrote:


On Fri, Jan 15, 2010 at 6:38 PM, Rick Macklem rmack...@uoguelph.ca  
wrote:



On Tue, 12 Jan 2010, Dan Naumov wrote:


For my upcoming storage system, the OS install is going to be on a
80gb Intel SSD disk and for various reasons, I am now pretty convinced
to stick with UFS2 for the root partition (the actual data pool will
be ZFS using traditional SATA disks). I am probably going to use GPT
partitioning and have the SSD host the swap, boot, root and a few
other partitions. What do I need to know in regards to partition
alignment and filesystem block sizes to get the best performance out
of the Intel SSDs?


I can't help with your question, but I thought I'd mention that there
was a recent post (on freebsd-current, I think?) w.r.t. using an SSD
for the ZFS log file. It suggested that that helped with ZFS perf., so
you might want to look for the message.

rick


I have managed to figure out the essential things to know by know, I
just wish there was a single, easy to grasp webpage or HOWTO
describing and whys and hows so I wouldn't have had had to spend the
entire day googling things to get a proper grasp on the issue :)


Maybe you can copy-paste your e-mail in a wiki somewhere. And your wish  
has come true for other peoples.


Ronald.




To (perhaps a bit too much) simplify things, if you are using an SSD
with FreeeBSD, you:

1) Should use GPT

2) Should create the freebsd-boot partition as normal (to ensure
compatibility with some funky BIOSes)

3) All additional partitions should be aligned, meaning that their
boundaries should be dividable by 1024kb (that's 2048 logical blocks
in gpart). Ie, having created your freeebsd-boot, your next partition
should start at block 2048 and the partition size should be dividable
by 2048 blocks. This applies to ALL further partitions added to the
disk, so you WILL end up having some empty space between them, but a
few MBs worth of space will be lost at most.

P.S: My oversimplification was in that MOST SSDs will be just fine
with a 512 kb / 1024 block alignment. However, _ALL_ SSDs will be fine
with 1024 kb / 2048 block alignment.


- Sincerely,
Dan Naumov
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(SOLVED) Re: installing FreeBSD 8 on SSDs and UFS2 - partition alignment, block sizes, what does one need to know?

2010-01-15 Thread Dan Naumov
On Fri, Jan 15, 2010 at 6:38 PM, Rick Macklem rmack...@uoguelph.ca wrote:


 On Tue, 12 Jan 2010, Dan Naumov wrote:

 For my upcoming storage system, the OS install is going to be on a
 80gb Intel SSD disk and for various reasons, I am now pretty convinced
 to stick with UFS2 for the root partition (the actual data pool will
 be ZFS using traditional SATA disks). I am probably going to use GPT
 partitioning and have the SSD host the swap, boot, root and a few
 other partitions. What do I need to know in regards to partition
 alignment and filesystem block sizes to get the best performance out
 of the Intel SSDs?

 I can't help with your question, but I thought I'd mention that there
 was a recent post (on freebsd-current, I think?) w.r.t. using an SSD
 for the ZFS log file. It suggested that that helped with ZFS perf., so
 you might want to look for the message.

 rick

I have managed to figure out the essential things to know by know, I
just wish there was a single, easy to grasp webpage or HOWTO
describing and whys and hows so I wouldn't have had had to spend the
entire day googling things to get a proper grasp on the issue :)

To (perhaps a bit too much) simplify things, if you are using an SSD
with FreeeBSD, you:

1) Should use GPT

2) Should create the freebsd-boot partition as normal (to ensure
compatibility with some funky BIOSes)

3) All additional partitions should be aligned, meaning that their
boundaries should be dividable by 1024kb (that's 2048 logical blocks
in gpart). Ie, having created your freeebsd-boot, your next partition
should start at block 2048 and the partition size should be dividable
by 2048 blocks. This applies to ALL further partitions added to the
disk, so you WILL end up having some empty space between them, but a
few MBs worth of space will be lost at most.

P.S: My oversimplification was in that MOST SSDs will be just fine
with a 512 kb / 1024 block alignment. However, _ALL_ SSDs will be fine
with 1024 kb / 2048 block alignment.


- Sincerely,
Dan Naumov
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