Re: (SOLVED) Re: installing FreeBSD 8 on SSDs and UFS2 - partition alignment, block sizes, what does one need to know?
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 ___ freebsd...@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-fs To unsubscribe, send any mail to freebsd-fs-unsubscr...@freebsd.org ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
(SOLVED) Re: installing FreeBSD 8 on SSDs and UFS2 - partition alignment, block sizes, what does one need to know?
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 ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org
installing FreeBSD 8 on SSDs and UFS2 - partition alignment, block sizes, what does one need to know?
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? Thanks. - Sincerely, Dan Naumov ___ freebsd-questions@freebsd.org mailing list http://lists.freebsd.org/mailman/listinfo/freebsd-questions To unsubscribe, send any mail to freebsd-questions-unsubscr...@freebsd.org