2

I've recently came across several servers with different "strategies" for their /boot partition (btw, always as /dev/sda1, 512M)

Some servers use ext2 for /boot, some use ext3 for /boot, and for the latter some have turned off journaling or turned off journaling and added the sync option. I won't take relatime and similar in account since I don't believe those atime options are relevant here.

  • Are there any important and relevant differences between an ext2 partition and a ext3 partition with journaling turned off for a /boot partition? I believe that online file system growth and htrees have no use at all for a /boot partition and I don't see what else ext3 offers over ext2.

  • Would "sync" option be recommended if there is no journaling?

  • Does any of these setups stand out from the rest in terms of easy of administration in case of crash/panic/oops or performance wise?

  • Is there any general consensus on the partition/format type for such a small (512MB) /boot partition should be?

BlakBat
  • 274
  • 1
  • 3
  • 9

1 Answers1

3

From a functional standpoint, ext3 is ext2 + journaling.
Using ext3 without journaling means to use an ext2 filesystem, but with a more recent code base (ext3's one).

However, there is not reason why you can't use ext4 as a boot partition, as Grub supports it since years.

The 512 MB limit for a boot partition is a vestige of some very old BIOS which can not boot from a partition larger the 512 MB. You can not use whichever size you want for your boot partition, but anything over 512-1024 MB is overkill.

shodanshok
  • 44,038
  • 6
  • 98
  • 162
  • 1
    Note: recent (2014+, I think) kernels use the same "ext4" code to access ext2/3/4 partitions, since the backward compatibility is excellent. Specifying ext2/ext3/ext4 only toggles default functionality bits (and what mount options you can/cannot request explicitly). – Piskvor left the building Jan 12 '16 at 10:02
  • @Piskvor Thanks for the info. I haven't gone in the kernel source for a while, I guess I'm going to check the info you just gave me. – BlakBat Jan 12 '16 at 10:20
  • @BlakBat: Based off Linux Kernel News, I didn't bother to go all the way *ad fontes* (although links were provided :)). – Piskvor left the building Jan 12 '16 at 10:26