“Many Unix administrators always used to smirk when I talked about Linux. They could always point to the fact that regardless of whatever I could say, they had journaling file systems, which they could manage using various Logical Volume Management (LVM) tools, and I couldn’t touch that.” Read the article here.
Getting started with RHEL4’s built-in LVM tools
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Eugenia Loli
Ex-programmer, ex-editor in chief at OSNews.com, now a visual artist/filmmaker.
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Suse has had this feature for years, why is it worth posting?
When looking at the documentation I did not find whether it is possible to grow an ext3 filesystem (on top of an LVM volume) “live” (without unmounting it).
Does someone knows if it is possible (and if possible, give a link)
I look forward to the day when Linux filesystems have the features of Tru64 AdvFS.
Yes, this is possible, it requires a new enough kernel (or patched kernel) as is included in RHEL4
On your RHEL4 system type ‘man ext2online’
e.g. to make a 40GB filesystem mounted as /home/science/data into a ~160Gbyte filesystem, assuming that you’ve already used LVM to resize its container you type…
ext2online /home/science/data 160G
This looks good and all that, but I still lack EVMS (http://evms.sourceforge.net/) support in Redhat/Fedora.
I’ve used LVM1 and it has a 2TB limit… I moved to LVM2 which is very good with Reiser, but mounting takes ages! Then moved over to LVM2 and XFS. This is currently a winner for me, all on line a mounts in a couple of seconds
To praise Redhat’s decision to not include other/better journaling filesystems is a joke.
Suse has had this feature for years, why is it worth posting?
Since you obviously only know SuSE: So does Red Hat, which supported LVM since Red Hat Linux 8. And if you read the article, it is not about introducing LVM as something completely new (although LVM2 is new in Red Hat Enterprise Linux 4).
“To praise Redhat’s decision to not include other/better journaling filesystems is a joke.”
you can install and use pretty much whatever FS you want (reiserfs, xfs, jfs) but Red Hat has chosen to only support ext2 and ext3.
Besides, I have never had a problem with ext3, but I HAVE had reiserfs die a bloody death. XFS seems nice, but everything I’ve read about it seems to say that you should only use it if you have a UPS. I have no personal experience at all with JFS.
“Suse has had this feature for years, why is it worth posting?”.
Please remember that this might be news to other users. Different people use different Os/tools/etc. Just becouse you know that not means that someone else does. Please give Eugenia a break…
Remeber this web site is not just for you but for others as well.
How recently? I thought reiserfs going down was something from the early 2.4 series kernel. At work we’ve got about 50TB worth of raid5 file systems running reiserfs. The only times we hvae problems with the filesystems are when drives start losing sectors and the raid5 doesn’t detect them right away.
At work we’ve got about 50TB worth of raid5 file systems running reiserfs.
That must that a while to mount? How offent is your server rebooted, if at all? As I would like to know how long something like that would take to mount. My 2TB (JBOD) takes over a minute to mount.
To praise Redhat’s decision to not include other/better journaling filesystems is a joke.
After reading your comment, I reread the 2nd paragraph twice. I think the 2nd paragraph is not about other journaling filesystems, it is just about ext3 is a better choice than ext2.
There are various reasons for Red Hat not to support ReiserFS. The most important one is that ReiserFS does not supporte extended attributes, which is essential for SELinux.
Does someone knows if it is possible (and if possible, give a link)
Yes. Did that about 20 times so far.
google is your friend. “lvm howto” and there is everything you need to know.
btw. Live or “not Live” resize differs in one thing only. If you unmount the volume or not, all the rest is same procedure
As for journaling filesystems included or not. You can use any linux supported FS. It is just a feature of GUI that does not support other filesystems.
Reiserfs has support for extended attributes, I use it with beagle to search my data. Yopu just need to have it enabled in the kernel.
Reiser4 does not have support for the standard extended attributes though, I believe it has it’s own or will be added as a plug-in.
“Reiserfs has support for extended attributes, I use it with beagle to search my data. Yopu just need to have it enabled in the kernel.
”
Working Reiserfs xattr support was only added in the recent 2.6.12-rc1 so FC4 version will have support for this (http://www.livejournal.com/users/james_morris/3580.html) . Red Hat Enterprise Linux 4 shipped with 2.6.9 based kernel. SELinux with reiserfs wouldnt work in it.
Ext3 itself has much improved performance after the addition of block reservation patches which is in RHEL 4
http://lwn.net/Articles/81357/
http://people.redhat.com/arjanv/reservations.png
Reiser4 does not have support for the standard extended attributes though, I believe it has it’s own or will be added as a plug-in.
Well, this is the issue. Since kernel features such as the LSM requires a standard EA, you cannot simply argue ReiserFS has some other (API) form, too, and expect it to work.
By the way: I think earlier ReiserFS had no EA at all. At least in the timeframe when the LSM development started, ReiserFS was not an option at all.
In previous version of the lvm howto, you could read that snapshots wasn’t possible with LVM2. Now, I can’t see such warnings. Does this mean that it works? Anybody that have tested it on RHE4 or Fedora FC3?
http://www.tldp.org/HOWTO/LVM-HOWTO/snapshotintro.html
I tried to look in the install options but could not find ReiserFS only ext3 and one more thing how much of a difference would RHEL 4 makae compared to Fedora 3 (oe Fedora 4) when installing on a single cpe machine.
Ext3/2 is supported. other filesystems are not. If you want a comparison between Fedora and Red Hat Enterprise Linux, take a look here.
http://www.redhat.com/software/rhelorfedora/
The software bits are pretty close
you can upgrade your ext2 partition to ext3 and then mount it as an ext2 at any time.
I wonder, will OpenSolaris be able to migrate from UFS to ZFS? Will it be able to mount a ZFS partition as UFS?
so what’s the difference between lvm2 and evms?
As originally conceived EVMS was to replace LVM in the kernel, and provide a suite of management tools with a nice GUI.
Linus declined to merge EVMS kernel code, choosing LVM2 instead, and that meant the plan changed. These days EVMS is mostly about interface. That means a nice GUI, but also a lot of management features. So you can’t do anything with EVMS that was impossible with MD + LVM2 + etc. but it is easier.
In the article, Ken Milberg wrote:
It also came up with the message that said “This release supports the ext3 journaled f/s. Migration to the new version with data loss?” Because I had already created another partition on the system, I picked “yes,” and it worked beautifully. The migration to ext3 from my existing ext2 partition also worked perfectly. After the upgrade was finished, I booted up, and verified that all the data was still in place — and it was. The file system successfully migrated to ext3 from ext2.
Frankly, how can that be an “Enterprise Administrator” article if the author apparently never heard of “tune2fs” which adds a journal to an ext2 partition, making it mountable as ext2 *and* ext3 without losing any data? Every student (like me) can find this information in no time…