#What's the difference between these?

user2002 · 10-15-2008, 12:22 PM

I've been a long time reiserfs user, since 2002.

The project I'm doing involves an ext3 journalised fs.

What is the difference between:

1. mkfs.ext3 /dev/sda1
and
2. mkfs.ext3 -j /dev/sda1

Are they both journalised or just the second one with the -j option?

By the way, I had a look at the man page but the explanation is quite vague. I personally think it is a journal fs on both cases but someone with more experince on ext2/ext3 would know the answer straight away.

Cheers

unSpawn · 10-15-2008, 01:25 PM

From 'man mkfs.ext3': "if called as mkfs.ext3 a journal is created as if the -j option was specified", so you don't need "-j" if you use the "mkfs.ext3" command.

i92guboj · 10-15-2008, 01:39 PM

The only technical difference between ext2 and 3 is the journal. So, using mkfs.ext3 -j is really redundant. -j has a real meaning when you use mke2fs.

user2002 · 10-16-2008, 02:47 AM

Thank you for the answers, all helpful.

Here is what I found, just in case someone else is interested to know:

mkfs.ext3 /dev/sda1
mkfs.ext3 -j /dev/sda1
mke2fs -j /dev/sda1

Apparently all three commands will create an ext3 journalised file system.

The difference is they will be checked by the system respectively:
after it has been mounted 21 times
after it has been mounted 37 times
after it has been mounted 20 times.

arun natarajan · 05-20-2016, 02:38 AM

What kind of check will be done by the system after respective number of mounts ??

Hope the system will be scanning the partitions for data and for other parameters.

syg00 · 05-20-2016, 03:20 AM

Duplicate post - as well as waking up a long dead thread

sundialsvcs · 05-20-2016, 07:14 AM

... Yeah, and information that old is probably no longer accurate, anyway.

(Unfortunately, many forums and other Internet sources, while giving the "month and day" that a post was created, neglect to provide the year. Search engines, also, when looking for "relevancy," tend to consider only content ... because they probably don't have a way to know when a post was written. ("It looks good to me, but, then again, I am a computer.")

Linux is changing very fast these days, and only the most-current information should be relied upon.