Partition alignment under Linux

[soleblaze]

Does anyone know a guide to do partition alignment in Linux? I assume regular partitions are aligned correctly if you use plain partitions with fdisk. However, what about LVM or encrypted partitions?

[Amozz]

Does anyone know a guide to do partition alignment in Linux? I assume regular partitions are aligned correctly if you use plain partitions with fdisk. However, what about LVM or encrypted partitions?

Use plain ol' fdisk. 'x' command to get "advanced", and 'u' to change units to cylinders instead of sectors. It will complain about misalignments, but it doesn't seems to have any bad effect that I have seen so far.

[AngryHerring]

Look at Pigeon's guide at page 9 "Partition alignment importance under Windows XP (32-bit and 64-bit)..why it cures stuttering and increases drive working life"

direct link: http://www.ocztechnologyforum.com/fo...&postcount=134

[soleblaze]

Thanks for the replies. Looks like I'm going to reinstall my laptop later today. I don't think I'll use LVM this time around, as I don't care that much about hibernation (LVM makes it a lot easier to use hibernation on an encrypted setup)

[tytso]

Does anyone know a guide to do partition alignment in Linux? I assume regular partitions are aligned correctly if you use plain partitions with fdisk. However, what about LVM or encrypted partitions?

You may find this useful. http://thunk.org/tytso/blog/2009/02/...se-block-size/

[soleblaze]

Ok, dredging this up again since I just ordered a Vertex 60gb. I'm going to follow the guide posted, however I'm also looking at setting up LUKS encryption for the LVM. cryptsetup has an –align-payload option, but I'm unsure what to use for it. Has anyone read or done anything with this before? If not, I'll research it a bit later this week, so I can find out the best way to go about setting up this drive

[jwilliams315]

I used my first SSD in a windows laptop, so I used the advice given in sticky's here for aligning the partition with the windows partition editor.

I'm about to put an SSD into my linux box, and I am planning to use fdisk -H 128 -S 32 , so 128 heads and 32 sectors per track. I like powers of 2. Note that the sector size will be 512 bytes. That gives me a pretty looking 2048KB (128*32*512 bytes) cylinder size, which will be aligned for just about any reasonable SSD page or erase block size. Except for the first partition. Since fdisk by default reserves the first track of the disk, my first partition will be offset by 16KB (32*512 bytes). I am just going to make the 1st partition as small as possible (2032KB will end it on the first cylinder boundary) and never use the first partition (I could go into expert mode to override the reserved first track, but I don't want to bother with the added complication). Then my second partition, and all the others, will be nicely aligned to 2048KB (and 1024KB, 512KB, etc.) boundaries.

[clarknova]

http://thunk.org/tytso/blog/2009/02/...se-block-size/

Ted Ts'o is the lead Ext4 developer. I'll be taking his advice when partitioning my Vertex this week. Although he recommends formatting with a stripe width of 32 if your SSD has an erase block size of 128k. Indications from elsewhere on this forum (search Octoploid's posts) and anandtech.com suggest that most drives including the Vertex use a block size of 512k, making a stripe width of 128 more appropriate apparently.

Ted recommends an initial partition offset of 128k, which has been suggested elsewhere in the forum, but I wonder with a 512k erase block size if a 512k partition alignment wouldn't be more appropriate.