Hi I have bought a ssd disk and Im not sure if I aligned it correctly. If I understand it correctly the starting sector should be dividable with 512 and it does not matter when the partition ends as long the next one starts on a sector dividable by 512 ?

This is the output from fdisk -luc

Disk /dev/sda: 240.1 GB, 240057409536 bytes
255 heads, 63 sectors/track, 29185 cylinders, total 468862128 sectors
Units = sectors of 1 * 512 = 512 bytes
Sector size (logical/physical): 512 bytes / 512 bytes
I/O size (minimum/optimal): 512 bytes / 512 bytes
Disk identifier: 0x8bfc5b06

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1            2048    33554431    16776192   83  Linux
/dev/sda2        33554432    65011711    15728640    7  HPFS/NTFS
/dev/sda3        65011712    81789439     8388864   82  Linux swap / Solaris
/dev/sda4        81789440   468862127   193536344   83  Linux

All linux partitions are formated as xfs are there any optimizations I can make ?(I have noatime already configured) The swap partition is for hibernating only


Like dieting, giving to charity and caring for the old we should all align our disks irrelevant of OS or disk type - it makes us better people :)

That said one of the reasons we do it is because it helps with the gulf between CPU/memory/bus speed and the much slower random or sequential read access we see in disks, this is of course much less important when using SSDs than with magnetic disks due to the significant performance benefits. However if you wish to align your SSD/s then there's no reason why you shouldn't treat them the same as magnetic disks and follow THIS previous questions answer.


Use noop scheduler for ssd, elevator=noop at the kernel commandline to see if your kernel supports noop use

cat /sys/block/sda/queue/scheduler

the scheduler between the brackets [ ] is the one in use

  • 1
    @Bart - this has nothing to do with the OP's alignment query. – Chopper3 Sep 2 '11 at 17:35

To verify a partition is aligned, query it using /usr/bin/blockdev as shown below. If a '0' is returned, the partition is aligned:

blockdev --getalignoff /dev/<partition>

Source: https://wiki.archlinux.org/index.php/Partitioning#Partition_alignment

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