Comments on: ext4 File System: Introduction and Benchmarks http://www.linux-mag.com/id/7271/ Open Source, Open Standards Sat, 05 Oct 2013 13:48:18 +0000 hourly 1 http://wordpress.org/?v=3.1 By: cwtryon http://www.linux-mag.com/id/7271/#comment-6271 cwtryon Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6271 Thanks for the introduction! While I realize that file systems can be an even more hotly debated religious topic than KDE vs. Gnome, do you have any indications on how ext4 performs compared to some of the other "new" file systems, such as JFS? One of the other big problems with ext3 has been handling massive numbers of really small files in a single directory. I actually worked a job where we were worried that a 2TB partition was "too small" for the amount of data we had to store, but we were stuck with older versions of RH EL, and not sure where to go. This may be the new way forward, as file system requirements continue to explode. Thanks for the introduction! While I realize that file systems can be an even more hotly debated religious topic than KDE vs. Gnome, do you have any indications on how ext4 performs compared to some of the other “new” file systems, such as JFS? One of the other big problems with ext3 has been handling massive numbers of really small files in a single directory. I actually worked a job where we were worried that a 2TB partition was “too small” for the amount of data we had to store, but we were stuck with older versions of RH EL, and not sure where to go. This may be the new way forward, as file system requirements continue to explode.

]]> By: laytonjb http://www.linux-mag.com/id/7271/#comment-6272 laytonjb Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6272 cwtryon,<br /> <br /> I agree with your thoughts about ext3 and ext4. In the past ext3 has felt kind of limiting and with RHEL that was the primary file system of choice. I've never tried to use JFS or Reiser on RHEL. Typically what I do is install RHEL using ext3 for / (I use ext2 for /boot), and once I'm happy, I build a new kernel with XFS and JFS enabled. I install all of the support tools and then build a new file system using XFS or JFS on other drives. This works well enough for me :)<br /> <br /> I don't know about performance of JFS vs. ext3 or ext4. One of my goals is to do some extensive benchmarking to get a feel for the relative performance differences. Drop a note to the editor about a file system benchmarking article and maybe he'll ask me to do one :)<br /> <br /> BTW - I'm working on a similar article for btrfs. While it's still experimental I want to get a feel for it as well. Ted Ts'o think the combination of ext4 and btrfs is the future and I couldn't agree more. There are some other up and coming file systems that show some promise as well.<br /> <br /> Also - thansk for the compliment! Glad it helped.<br /> <br /> Jeff cwtryon,

I agree with your thoughts about ext3 and ext4. In the past ext3 has felt kind of limiting and with RHEL that was the primary file system of choice. I’ve never tried to use JFS or Reiser on RHEL. Typically what I do is install RHEL using ext3 for / (I use ext2 for /boot), and once I’m happy, I build a new kernel with XFS and JFS enabled. I install all of the support tools and then build a new file system using XFS or JFS on other drives. This works well enough for me :)

I don’t know about performance of JFS vs. ext3 or ext4. One of my goals is to do some extensive benchmarking to get a feel for the relative performance differences. Drop a note to the editor about a file system benchmarking article and maybe he’ll ask me to do one :)

BTW – I’m working on a similar article for btrfs. While it’s still experimental I want to get a feel for it as well. Ted Ts’o think the combination of ext4 and btrfs is the future and I couldn’t agree more. There are some other up and coming file systems that show some promise as well.

Also – thansk for the compliment! Glad it helped.

Jeff

]]> By: ndatta http://www.linux-mag.com/id/7271/#comment-6273 ndatta Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6273 This is a great article and a very good introduction to ext4. Thanks! This is a great article and a very good introduction to ext4. Thanks!

]]> By: rkoski http://www.linux-mag.com/id/7271/#comment-6274 rkoski Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6274 Actually, the ext3 file system size limit is only 8 TB. Tried to make 9 TB ext3, but the only block size option was 4 KB, which resulted in said max 8 TB file system. Used CentOS 5.2. Maybe there is some combination of kernel, e2fsprogs, etc. which can use 8 KB blocks, perhaps kernel 2.4.x ;) Actually, the ext3 file system size limit is only 8 TB. Tried to make 9 TB ext3, but the only block size option was 4 KB, which resulted in said max 8 TB file system. Used CentOS 5.2. Maybe there is some combination of kernel, e2fsprogs, etc. which can use 8 KB blocks, perhaps kernel 2.4.x ;)

]]> By: dbindner http://www.linux-mag.com/id/7271/#comment-6275 dbindner Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6275 There's always something to complain about with benchmarks, so naturally I have a complaint. Given that this was a very introductory article, I think it would have made sense to test the two filesystems in the configurations that are most common, i.e. their default configurations.<br /> <br /> When more technical articles follow, you can delve into the options that a careful sysadmin would tune. But most people (and many admins) are going to use the default settings and will want to know about performance as well as reliability. It may be a bit hard to say about reliability for the moment, but at least that "typical" performance can be measured. There’s always something to complain about with benchmarks, so naturally I have a complaint. Given that this was a very introductory article, I think it would have made sense to test the two filesystems in the configurations that are most common, i.e. their default configurations.

When more technical articles follow, you can delve into the options that a careful sysadmin would tune. But most people (and many admins) are going to use the default settings and will want to know about performance as well as reliability. It may be a bit hard to say about reliability for the moment, but at least that “typical” performance can be measured.

]]> By: sparhawk http://www.linux-mag.com/id/7271/#comment-6276 sparhawk Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6276 Seems ext4 performs well against jfs and others. <br /> <br /> see: <br /> <br /> http://arstechnica.com/open-source/news/2009/01/super-fast-ext4-filesystem-arrives-in-ubuntu-9-04.ars Seems ext4 performs well against jfs and others.

see:

http://arstechnica.com/open-source/news/2009/01/super-fast-ext4-filesystem-arrives-in-ubuntu-9-04.ars

]]> By: graemeharrison http://www.linux-mag.com/id/7271/#comment-6277 graemeharrison Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6277 Great article... but I too have an issue about the benchmarking needing to compare 'out of the box' default configurations. You disabled "barriers" which are by-default ON with Ext4 (for cited reason of compatibility) but really, if Ext4 will have data-security features, at least one column in results should have been the default use of Ext4. Great article… but I too have an issue about the benchmarking needing to compare ‘out of the box’ default configurations. You disabled “barriers” which are by-default ON with Ext4 (for cited reason of compatibility) but really, if Ext4 will have data-security features, at least one column in results should have been the default use of Ext4.

]]> By: sdean7855 http://www.linux-mag.com/id/7271/#comment-6278 sdean7855 Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6278 Great article. Jeff, since you are an Enterprise Technologist for Dell, I have a question about the inter-relation/robustness/capability of ext4 and btrfs and PC hardware...or Dell server hardware. Ts'o wrote a <a href="http://linuxmafia.com/faq/Filesystems/reiserfs.html" rel="nofollow">telling piece</a> back in '04, entitled 'reiserfs' but it might as well have been entitled crappy PC hardware. It was his take back then that SGI and Sun had built their hardware to deal somewhat gracefully and sequentially with a power cord yank but that crappy PC hardware died a thrashing chaotic death that would write crap...even upon the metadata. Have things improved, at least with Dell Poweredge server hardware? Does ext4 and btrfs do physical journalling? Great article. Jeff, since you are an Enterprise Technologist for Dell, I have a question about the inter-relation/robustness/capability of ext4 and btrfs and PC hardware…or Dell server hardware. Ts’o wrote a telling piece back in ’04, entitled ‘reiserfs’ but it might as well have been entitled crappy PC hardware. It was his take back then that SGI and Sun had built their hardware to deal somewhat gracefully and sequentially with a power cord yank but that crappy PC hardware died a thrashing chaotic death that would write crap…even upon the metadata. Have things improved, at least with Dell Poweredge server hardware? Does ext4 and btrfs do physical journalling?

]]> By: gigo6000 http://www.linux-mag.com/id/7271/#comment-6279 gigo6000 Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6279 Nice article , just yesterday while installing ubuntu 9.04 I noticed this new filesystem and didn't know if it was ok to use it since ext3 works fine for my needs. Nice article , just yesterday while installing ubuntu 9.04 I noticed this new filesystem and didn’t know if it was ok to use it since ext3 works fine for my needs.

]]> By: rosbif http://www.linux-mag.com/id/7271/#comment-6280 rosbif Wed, 30 Nov -0001 00:00:00 +0000 http://www.linux-mag.com/id/7271/#comment-6280 <p>Thank you for a nice article.</p> <p>One little nit-pick:<br /> The maximum file size for ext2 is much greater than the 2GB stated.<br /> It depends on the block size but seems to be 2TiB with a 4KiB block size.</p> <p>Of course it is true that some 32-bit applications may be limited to a 2GiB maximum file size but this is a limitation of the application and not of the file system. </p> Thank you for a nice article.

One little nit-pick:
The maximum file size for ext2 is much greater than the 2GB stated.
It depends on the block size but seems to be 2TiB with a 4KiB block size.

Of course it is true that some 32-bit applications may be limited to a 2GiB maximum file size but this is a limitation of the application and not of the file system.

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