Partitioning a new SSD....totally lost

[whatthefunk]

I bought a new SSD today and am planning on doing a fresh install of 12.04 on it. However, I dont have a clue about partitioning.... Ive read about Erase Block Size and understand what it means and everything just dont know how to partition my drive to match it.

My SSD is 60 GB. I want two main partitions, one for Kubuntu and one for any future OSs I dual boot. Anybody?

[james147]

This might be of interest. Though not all of it might apply to ubuntu, the parts on partitioning and filesystems should be relevant.

[whatthefunk]

Thanks james...Ive been stumbling through that link for the last couple hours. I think Im over thinking this partitioning thing....

[james147]

Thanks james...Ive been stumbling through that link for the last couple hours. I think Im over thinking this partitioning thing....

Probably, for mine I just used a gpt table with btrfs and haven't had any problems with it. I think the only reason you shouldn't use gpt for an ssd is if you need windows.

If choosing to start on a sector before the 2048th gdisk will automatically shift the partition start to the 2048th disk sector. This is to ensure a 2048-sectors alignment (as a sector is 512B, this is a 1024KiB alignment which should fit any SSD NAND erase block).

Seems to suggest that gpt automatically aligns the partition tables for any common ssd.

[whatthefunk]

How do you do gpt?

[james147]

I use gdisk rather then fdisk... not sure what gui's support it though

[whatthefunk]

Okay....I was playing around with gdisk before but then chickened out and went back to KDE partition manager. Maybe Ill give it another go.

[james147]

Its not to hard to get use to jsut run

sudo gdisk /dev/sdX

(where /dev/sdX is the drive you want to partition) to start it then ? to get the help message

the useful keys are:
- o to create a new partition table
- n to create a new partition, I tend to hit enter twice as there is little point in not selecting the default partition and start size, then +10G to create a 10G partition or +50% to create a partition 50% of the space available.
- p to print the table
- w to save changes
- q to quit without saving

You can use cgdisk for a more friendly ncurses application as well

[SteveRiley]

Seems to suggest that gpt automatically aligns the partition tables for any common ssd.

Minor fixup... GPT is a partition type: GUID partition table. gdisk is the utility that can manipulate GPTs. The alignment smarts come from the tool; they aren't intrinsic to the partition type.

[whatthefunk]

Think I got it right. I set up the partitions using gdisk and then used the installation partitioner to set up file systems...is that ok?

[james147]

It should be fine to use the installer to set up the filesystems

[oshunluvr]

Short answer to your original post is: depends on the erase block size of your SSD.

Assuming 512k (OCZ uses this size among most others), partition using a geom 32 heads and 32 sectors and you'll have 512k blocks. You then need to start your first partition at the second cylinder to keep the alignment.

If you're using ext4 for your filesystem I've read to use a stride and stripe width of 128 and a 4k page file (will depend on your manufacturers specs):

sudo mkfs.ext4 -O extent -b 4096 -E stride=128,stripe-width=128 /dev/<YOUR DRIVE>

[SteveRiley]

Think I got it right. I set up the partitions using gdisk and then used the installation partitioner to set up file systems...is that ok?

This is exactly what I do.