[opensuse-factory] ext4 filesystem
As the next openSUSE now defaults to ext4, I'm wondering. I don't understand what I gain/miss with ext4/ext3. Is the benefit significant compared with ext3 and how? Is ext4 better for hard disks, is it perhaps much better for ssd? The price of solid state drives is coming down, and since I know nothing, I'm tempted. Should I go ext4/ssd? Should I go ext4/hdd? What do I miss if I stay ext3? Or should I go back to reiserfs? I never had an issue with it and the enterprice versions default to it. Vahis -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org
Vahis wrote:
I don't understand what I gain/miss with ext4/ext3.
I don't know all the details, but from all I read about kernel developmnet, ext4 is still rather experimental and not stable enough for solid enterprise production use. It's even worse with btrfs, which contains some reisrfs spirit and should be much better in terms of storage and even safety, but is also still under heavy development and not production-ready yet.
What do I miss if I stay ext3?
You at least gain a lot of stability the others can't yet provide.
Or should I go back to reiserfs? I never had an issue with it and the enterprice versions default to it.
Kernels starting from 2.6.28 or maybe somewhat earlier suffer from some hard to reproduce and never completely fixed race conditions in which fsync among others seems to play a role and which can result in completely locked ("dead", "uninterruptible sleep") processes accessing the file system. Also, extended attributes were never implemented really cleanly but are said to be somewhat hackish on reiserfs. It basically works, it's very good in terms of storage, but it's a second- or lesser-class citizen in current kernels and barely maintained. Right now, I think the most reasonable choice is ext3, as it's very well-maintained, problems are resolved fast, and it's very stable. It's not the best choice in the long term, but both ext4 and btrfs, which will be interesting in the future (one as the continuation of the ext line, one as a significantly improved new approach), are not stable enough for general recommendation from all I hear. I know that multiple distributions are switching to ext4 as the default, but all I hear about it makes me skecpitcal as to that being a good choice. Robert Kaiser -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org
KaiRo - Robert Kaiser wrote:
Vahis wrote:
I don't understand what I gain/miss with ext4/ext3.
I don't know all the details, but from all I read about kernel developmnet, ext4 is still rather experimental and not stable enough for solid enterprise production use. It's even worse with btrfs, which contains some reisrfs spirit and should be much better in terms of storage and even safety, but is also still under heavy development and not production-ready yet.
What do I miss if I stay ext3?
You at least gain a lot of stability the others can't yet provide. Thanks for supporting my intuition :) I've had no issues with it. When I learned to tune it to not force surprising checks in booting I've been quite cool with it :)
Or should I go back to reiserfs? I never had an issue with it and the enterprice versions default to it.
Kernels starting from 2.6.28 or maybe somewhat earlier suffer from some hard to reproduce and never completely fixed race conditions in which fsync among others seems to play a role and which can result in completely locked ("dead", "uninterruptible sleep") processes accessing the file system. Also, extended attributes were never implemented really cleanly but are said to be somewhat hackish on reiserfs. It basically works, it's very good in terms of storage, but it's a second- or lesser-class citizen in current kernels and barely maintained.
Right now, I think the most reasonable choice is ext3, as it's very well-maintained, problems are resolved fast, and it's very stable. It's not the best choice in the long term, but both ext4 and btrfs, which will be interesting in the future (one as the continuation of the ext line, one as a significantly improved new approach), are not stable enough for general recommendation from all I hear. I know that multiple distributions are switching to ext4 as the default, but all I hear about it makes me skecpitcal as to that being a good choice.
It feels like easy to agree with you. What you wrote supports my own impression. Any thoughts of solid state drives? Vahis -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org
Vahis wrote:
KaiRo - Robert Kaiser wrote:
Vahis wrote:
What do I miss if I stay ext3?
You at least gain a lot of stability the others can't yet provide. Thanks for supporting my intuition :)
Of course, I'm also just a user, I just happen to read LWN.net, including its excellent kernel articles, regularly.
Any thoughts of solid state drives?
I know that btrfs should be something that fits well with them because of its copy-on-write nature, but I'm not sure how others perform there. Given that SSDs are computers themselves and emulate spinning-disk-drives quite well from what I hear, I'm not sure how much difference the filesystem really makes on them. Robert Kaiser -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org
On Sat, Aug 22, 2009 at 3:29 PM, KaiRo - Robert Kaiser
Vahis wrote:
KaiRo - Robert Kaiser wrote:
Vahis wrote:
What do I miss if I stay ext3?
You at least gain a lot of stability the others can't yet provide.
Thanks for supporting my intuition :)
Of course, I'm also just a user, I just happen to read LWN.net, including its excellent kernel articles, regularly.
Any thoughts of solid state drives?
I know that btrfs should be something that fits well with them because of its copy-on-write nature, but I'm not sure how others perform there. Given that SSDs are computers themselves and emulate spinning-disk-drives quite well from what I hear, I'm not sure how much difference the filesystem really makes on them.
Robert Kaiser
Current generation drives (rotating and ssd) are ATA7 spec. Next generation ssd's will be ATA8 draft spec compliant. Initial drives are already on the market that offer support for "trim" which is the main new feature of ata8. Anyway, ext2/3 is unlikely to ever see support for trim. Meaning they will not ever be optimized for next generation ssd's. ext4 / xfs / btrfs should all see trim support added. They may all already have it in 2.6.31 kernels, but the lower level driver support won't be there until 2.6.32 at the earliest. iirc, Mark Lord has written a companion tool to hdparm that will "trim" a complete filesystem of unused sectors. It depends on fallocate(). Also a feature not likely to ever see support in ext2 / ext3. Basically ext2 / ext3 are fine for todays ssd's, but not tomorrows. Greg -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org
Greg Freemyer wrote: <snip>
Basically ext2 / ext3 are fine for todays ssd's, but not tomorrows.
Greg
Thanks for great information :) So, all in all: I'll keep hard drive I'll keep ex3 I'll come back in the future on this :) Vahis -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org
On 22/08/09 19:47, KaiRo - Robert Kaiser wrote:
Vahis wrote:
I don't understand what I gain/miss with ext4/ext3.
I don't know all the details, but from all I read about kernel developmnet, ext4 is still rather experimental and not stable enough for solid enterprise production use. It's even worse with btrfs, which contains some reisrfs spirit and should be much better in terms of storage and even safety, but is also still under heavy development and not production-ready yet.
What do I miss if I stay ext3?
You at least gain a lot of stability the others can't yet provide.
Or should I go back to reiserfs? I never had an issue with it and the enterprice versions default to it.
Kernels starting from 2.6.28 or maybe somewhat earlier suffer from some hard to reproduce and never completely fixed race conditions in which fsync among others seems to play a role and which can result in completely locked ("dead", "uninterruptible sleep") processes accessing the file system. Also, extended attributes were never implemented really cleanly but are said to be somewhat hackish on reiserfs. It basically works, it's very good in terms of storage, but it's a second- or lesser-class citizen in current kernels and barely maintained.
Right now, I think the most reasonable choice is ext3, as it's very well-maintained, problems are resolved fast, and it's very stable. It's not the best choice in the long term, but both ext4 and btrfs, which will be interesting in the future (one as the continuation of the ext line, one as a significantly improved new approach), are not stable enough for general recommendation from all I hear. I know that multiple distributions are switching to ext4 as the default, but all I hear about it makes me skecpitcal as to that being a good choice.
Robert Kaiser
I use XFS mostly and ext3 in a couple of boxes. I have a 500G drive formatted with BTRFS that I use solely for backup, just in case, it's not my only backup. I hope to use it for some other stuff like building applications - I like testing new things. Linus is reported as using btrfs for his root partition - Greg KH, are you doing anything significant with btrfs?. In a rather lengthy article describing he design of btrfs, it's more like ZFS for Solaris, but with much more efficient and smarter. It's slated to replace ext4 a bit further down the road. Regards Sid. -- Sid Boyce ... Hamradio License G3VBV, Licensed Private Pilot Emeritus IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Specialist, Cricket Coach Microsoft Windows Free Zone - Linux used for all Computing Tasks -- To unsubscribe, e-mail: opensuse-factory+unsubscribe@opensuse.org For additional commands, e-mail: opensuse-factory+help@opensuse.org
participants (4)
-
Greg Freemyer -
KaiRo - Robert Kaiser -
Sid Boyce -
Vahis