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graysky

Wiki Maintainer

From: :wq

Registered: 2008-12-01

Posts: 10,597

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ext4 newbie questions

I just purchased a new hdd for backups via rsync and am seriously considering formating it to ext4 since this seems to be the new standard and offers speed benifits.  I have several questions about it though:

1) Where is this online defrag util I've read about?  I've searched in the repos but didn't see anything obvious?
2) The speed advantages I've read about are totally native to the format without me doing anything/special setup, no?  My plan was to just boot into gparted's live CD and make/format the partition from there.  Is that it?
3) Is there any special maintenance I need to do or is a line in my /etc/fstab going to be enough to have fsck run on it automatically after 30 boots like it does my ext3 partitions?

/dev/sdb1 /media/backup ext4 defaults 0 2

Thanks!

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Nezmer

Member

Registered: 2008-10-24

Posts: 559

Website

Re: ext4 newbie questions

I just purchased a new hdd for backups via rsync and am seriously considering formating it to ext4 since this seems to be the new standard and offers speed benifits.  I have several questions about it though:

1) Where is this online defrag util I've read about?  I've searched in the repos but didn't see anything obvious?
2) The speed advantages I've read about are totally native to the format without me doing anything/special setup, no?  My plan was to just boot into gparted's live CD and make/format the partition from there.  Is that it?
3) Is there any special maintenance I need to do or is a line in my /etc/fstab going to be enough to have fsck run on it automatically after 30 boots like it does my ext3 partitions?

/dev/sdb1 /media/backup ext4 defaults 0 2

Thanks!

1) It's not available yet . Maybe in the next kernel release (2.6.30) .
2) * yes , default mount options will provide performance improvement .
     * I'm not sure If gparted supports ext4 natively . Why not use 'mkfs.ext4' ?
3)

$ tune2fs -l /dev/disk/by-label/Storage
.
.
Filesystem created:       Mon Dec 29 14:04:09 2008
Last mount time:          Wed Mar 11 13:59:43 2009
Last write time:          Sun Mar 29 14:42:59 2009
Mount count:              4
Maximum mount count:      32
Last checked:             Wed Feb 25 00:21:20 2009
Check interval:           15552000 (6 months)
Next check after:         Mon Aug 24 01:21:20 2009
.
.

Last edited by Nezmer (2009-04-06 22:46:48)

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English is not my native language .

subatomic

Member

From: Berlin

Registered: 2005-06-26

Posts: 180

Re: ext4 newbie questions

I'm interested in knowing this as well. I formatted a 500GB SATA drive to ext4 with gparted and got horrible speed, like 400 KB/s whereas copying to my USB external drive was much faster. I just reformatted it to ext3 and transfers are now at 4.5 MB/s.

MoonSwan

Member

From: Great White North

Registered: 2008-01-23

Posts: 881

Re: ext4 newbie questions

Search for posts by Ranguvar on the Ext4 FS.

grndrush

Member

From: Hamilton, Ontario, Canada

Registered: 2003-12-28

Posts: 136

Website

Re: ext4 newbie questions

2. I haven't noticed anything special relative to ext3/ReiserFS. I haven't done any testing, but no, it doesn't seem "fast."

3. the same as ext3. *IMX*, a bit more prone to data loss across a hard reset.

(4.) It takes 25% more space than an identical ReiserFS setup. No experience relative to ext3.

Last edited by grndrush (2009-04-08 08:57:27)

graysky

Wiki Maintainer

From: :wq

Registered: 2008-12-01

Posts: 10,597

Website

Re: ext4 newbie questions

I'm not sure If gparted supports ext4 natively . Why not use 'mkfs.ext4' ?

The latest gparted does indeed support ext4.  I used it to create my partition and lookin at its logs, it did the following:

mkfs.ext4 -j -O extent -L " " /dev/sdd1

So -j creates the partition with an ext3 journal (according to the manpage)?  Is that right?

Last edited by graysky (2009-04-08 21:02:31)

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Nezmer

Member

Registered: 2008-10-24

Posts: 559

Website

Re: ext4 newbie questions

So -j creates the partition with an ext3 journal (according to the manpage)?  Is that right?

The man page is for "mke2fs" . I think "mkfs.ext4" is a wrapper that would add necessary arguments to "mke2fs" to properly create an ext4 partition . So as far as I know "mkfs.ext4" adds  -j  by default (at least before kernel 2.6.29 which introduced ext4 without journal) .

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English is not my native language .