1. Feature Overview: Feature Id: [60120] a. Name of Feature: [5.6 FEAT] Support ext4 filesystem in RHEL5.6 b. Feature Description Ext4 was created to incorporate scalability and performance enhancements in support of large filesystems, while maintaining reliability and stability. We want to have ext4 fully supported. 2. Feature Details: Sponsor: LTC Filesystems Architectures: ppc64x86x86_64 Arch Specificity: purely common code Affects Kernel Modules: Yes Delivery Mechanism: Direct from Community Category: kernel Request Type: Kernel - Enhancement from Upstream d. Upstream Acceptance: Accepted Sponsor Priority P2 f. Severity: high IBM Confidential: No Code Contribution: IBM code g. Component Version Target: --- 3. Business Case These filesystem enhancements are critical to Linuxes ability to scale with enterprise workloads and facilitate competition against other OS's in these markets. This is especially true for DB2. 4. Primary contact at Red Hat: John Jarvis jjarvis 5. Primary contacts at Partner: Project Management Contact: Stephanie A. Glass, sglass.com Technical contact(s): Mingming Cao, mcao.com
------- Comment From mcao.com 2010-03-30 15:19 EDT------- Moving this feature to submitted status. Redhat, please let us know if you need anything from us Thanks, Mingming
This enhancement request was evaluated by the full Red Hat Enterprise Linux team for inclusion in a Red Hat Enterprise Linux minor release. As a result of this evaluation, Red Hat has tentatively approved inclusion of this feature in the next Red Hat Enterprise Linux Update minor release. While it is a goal to include this enhancement in the next minor release of Red Hat Enterprise Linux, the enhancement is not yet committed for inclusion in the next minor release pending the next phase of actual code integration and successful Red Hat and partner testing. This work will be tracked in https://bugzilla.redhat.com/show_bug.cgi?id=457153 *** This bug has been marked as a duplicate of bug 457153 ***
Leaving open and leaving as a dependency of https://bugzilla.redhat.com/show_bug.cgi?id=457153 where the work will be done.
This enhancement request was evaluated by the full Red Hat Enterprise Linux team for inclusion in a Red Hat Enterprise Linux minor release. As a result of this evaluation, Red Hat has tentatively approved inclusion of this feature in the next Red Hat Enterprise Linux Update minor release. While it is a goal to include this enhancement in the next minor release of Red Hat Enterprise Linux, the enhancement is not yet committed for inclusion in the next minor release pending the next phase of actual code integration and successful Red Hat and partner testing.
From internal RHBZ 457153 which is tracking this work: The necessary patches are now included in kernel build 2.6.18-217.el5:
------- Comment From mcao.com 2010-11-29 15:58 EDT------- Found RHEL5.6 release notes, saying ext4 is fully supported and e4progs/e2fsprogs has been upgrade to latest upstream version. http://docs.redhat.com/docs/en-US/Red_Hat_Enterprise_Linux/5/html/5.6_Release_Notes/ar01s05.html ------------------------------------------------------------------- Fourth Extended Filesystem (ext4) Support The fourth extended filesystem (ext4) is now a fully supported feature in Red Hat Enterprise Linux 5.6. ext4 is based on the third extended filesystem (ext3) and features a number of improvements, including: support for larger file systems and larger files, faster and more efficient allocation of disk space, no limit on the number of subdirectories within a directory, faster file system checking, and more robust journaling. To complement the addition of ext4 as a fully supported filesystem in Red Hat Enterprise Linux 5.6 Beta, the e4fsprogs package has been updated to the latest upstream version. e4fsprogs contains utilities to create, modify, verify, and correct the ext4 filesystem. ---------------------------------------------------------------------- I booted a RHEL5.6 box, ext4 is avalible as a module, I am able to load ext4 module and create/mount ext4 filesystem and do simple IO without problem. One thing puzzled me is the default ext4 journalling mode. When I created a ext4 partition, 1) dmesg says EXT4-fs (sda6): mounted filesystem without journal SELinux: initialized (dev sda6, type ext4), uses xattr 2) /proc/mounts indicates ext4 is mounted with data=writeback mode. [root@elm3a112 ext4]# cat /proc/mounts /dev/sda6 /tmp/ext4 ext4 rw,barrier=1,data=writeback 0 0 I am expecting ext4 is mounted with data=ordered mode (like ext3) by default. Has this been changed in RHEL5.6?
(In reply to comment #9) > ------- Comment From mcao.com 2010-11-29 15:58 EDT------- > One thing puzzled me is the default ext4 journalling mode. When I created a > ext4 partition, > > 1) dmesg says > > EXT4-fs (sda6): mounted filesystem without journal > SELinux: initialized (dev sda6, type ext4), uses xattr > > 2) /proc/mounts indicates ext4 is mounted with data=writeback mode. > > [root@elm3a112 ext4]# cat /proc/mounts > > /dev/sda6 /tmp/ext4 ext4 rw,barrier=1,data=writeback 0 0 > > I am expecting ext4 is mounted with data=ordered mode (like ext3) by default. > Has this been changed in RHEL5.6? Very odd; not intentional, let me look into this. # mkfs.ext4 /dev/ram0 mke4fs 1.41.12 (17-May-2010) ... # mount /dev/ram0 /mnt/test # dmesg | tail -n 2 EXT4-fs (ram0): mounted filesystem with ordered data mode SELinux: initialized (dev ram0, type ext4), uses xattr [root@gfs-a16c-02 ~]# grep ext4 /proc/mounts /dev/ram0 /mnt/test ext4 rw,barrier=1,data=ordered 0 0 # uname -a Linux gfs-a16c-02.mpc.lab.eng.bos.redhat.com 2.6.18-232.el5 #1 SMP Mon Nov 15 16:01:45 EST 2010 x86_64 x86_64 x86_64 GNU/Linux seems ok here; do you have something interesting in /etc/mke4fs.conf? -Eric
------- Comment From mcao.com 2010-11-29 19:47 EDT------- (In reply to comment #11) > (In reply to comment #9) > > One thing puzzled me is the default ext4 journalling mode. When I created a > > ext4 partition, > > > > 1) dmesg says > > > > EXT4-fs (sda6): mounted filesystem without journal > > SELinux: initialized (dev sda6, type ext4), uses xattr > > > > 2) /proc/mounts indicates ext4 is mounted with data=writeback mode. > > > > [root@elm3a112 ext4]# cat /proc/mounts > > > > /dev/sda6 /tmp/ext4 ext4 rw,barrier=1,data=writeback 0 0 > > > > I am expecting ext4 is mounted with data=ordered mode (like ext3) by default. > > Has this been changed in RHEL5.6? > Very odd; not intentional, let me look into this. > # mkfs.ext4 /dev/ram0 > mke4fs 1.41.12 (17-May-2010) > ... > # mount /dev/ram0 /mnt/test > # dmesg | tail -n 2 > EXT4-fs (ram0): mounted filesystem with ordered data mode > SELinux: initialized (dev ram0, type ext4), uses xattr > [root@gfs-a16c-02 ~]# grep ext4 /proc/mounts > /dev/ram0 /mnt/test ext4 rw,barrier=1,data=ordered 0 0 > # uname -a > Linux gfs-a16c-02.mpc.lab.eng.bos.redhat.com 2.6.18-232.el5 #1 SMP Mon Nov 15 > 16:01:45 EST 2010 x86_64 x86_64 x86_64 GNU/Linux > seems ok here; do you have something interesting in /etc/mke4fs.conf? > -Eric Thanks Eric for quick verifying. It is not a problem here after re-verifying. It seems I was confused with e2fsprogs and e4fsprogs. Initially I used mke2fs - T ext4 to create the fs, thought I get a ext4 fs successfully created, but it actually created an ext2 fs for me, as it reads configs from /etc/mke2fs.conf. Then I used mke4fs -T ext4 to create the fs, but didn't realize that need to use -t to specify the fs type, -T is used for something else. So I ends up an ext2 partition again without realize it. Mingming
Thanks for the update, I will close out this BZ then.... Please re-open if I missed something, Ric
Sorry - I was thinking that this was a BZ specific to the issue raised in https://bugzilla.redhat.com/show_bug.cgi?id=563943#c10. This should stay open until confirmed.
Thanks Mingming - hm, that is a little unfortunate, since the old mke2fs does not understand -T the way the new one does. :( "mke4fs" should work though :) I wonder if we need to do something to mke2fs to catch this or if it's just a case of Reading The Fine Manual. :) -Eric
Technical note added. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. New Contents: Ext4 is a fully supported fil esystem as of RHEL5.6. However, provisioning ext4 file systems via the anaconda installer is not supported, and ext4 file systems should be provisioned manually post-install.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1 +1 @@ -Ext4 is a fully supported fil esystem as of RHEL5.6. However, provisioning ext4 file systems via the anaconda installer is not supported, and ext4 file systems should be provisioned manually post-install.+Ext4 is a fully supported file system as of RHEL5.6. However, provisioning ext4 file systems via the anaconda installer is not supported, and ext4 file systems should be provisioned manually post-install.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1 +1 @@ -Ext4 is a fully supported file system as of RHEL5.6. However, provisioning ext4 file systems via the anaconda installer is not supported, and ext4 file systems should be provisioned manually post-install.+As of Red Hat Enterprise Linux 5.6 the ext4 file system is fully supported. However, provisioning ext4 file systems with the anaconda installer is not supported, and ext4 file systems need to be added manually after the installation.
Technical note updated. If any revisions are required, please edit the "Technical Notes" field accordingly. All revisions will be proofread by the Engineering Content Services team. Diffed Contents: @@ -1 +1 @@ -As of Red Hat Enterprise Linux 5.6 the ext4 file system is fully supported. However, provisioning ext4 file systems with the anaconda installer is not supported, and ext4 file systems need to be added manually after the installation.+As of Red Hat Enterprise Linux 5.6 the ext4 file system is fully supported. However, provisioning ext4 file systems with the anaconda installer is not supported, and ext4 file systems need to be provisioned manually after the installation.
For people trying to set up ext4 on RHEL5.x, see: http://etbe.coker.com.au/2010/01/05/ext4-and-rhel5-centos5/
That guide suggests conversions from ext3 to ext4, which is not supported or recommended in RHEL. And following the instructions won't get you a filesystem with extents. A fresh mkfs.ext4 will fully enable all features and properly set up all metadata structures on disk. Anything else will leave you with half a solution and untested, at that. The RHEL6 Storage Administrator's Guide at https://access.redhat.com/knowledge/docs/en-US/Red_Hat_Enterprise_Linux/6/html/Storage_Administration_Guide/newfilesys-ext4.html is mostly applicable to RHEL5 as well, and would be a much better guide.
Eric, so, I tested mkfs.ext4 before I wrote the above. I creates (according to parted on a fully updated 5.8 box) an ext3 filesystem.
parted doesn't know how to distinguish the two, apparently. # rpm -q e4fsprogs e4fsprogs-1.41.9-3.el5 # mkfs.ext4 /dev/sdb2 ... # blkid /dev/sdb2 /dev/sdb2: UUID="2a512ea0-906d-4bb6-998f-602de627f285" TYPE="ext4" # file -s /dev/sdb2 /dev/sdb2: Linux rev 1.0 ext4 filesystem data (extents) (large files) (huge files) # parted -l ... Disk /dev/sdb: 1633GB Sector size (logical/physical): 512B/512B Partition Table: msdos Number Start End Size Type File system Flags 1 32.3kB 32.0GB 32.0GB primary xfs boot 2 32.0GB 64.0GB 32.0GB primary ext3 3 64.0GB 68.0GB 4006MB primary ext3 4 68.0GB 1633GB 1565GB primary xfs
Anyway, closed bugzilla's aren't really the proper support avenue. ;) Red Hat support contacts (or Centos forums) are probably better...
Later versions of parted (like v3.1) see the partition correctly as ext4 (on RHEL5)