Reiser4 Gentoo FAQ [25Dec2016]

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vacula · Post by **vacula** » Mon Dec 27, 2010 1:29 pm

Hi all,

are there any recomendations regarding using reiser 4 on SSD drives?
does anybody know whether reiser 4 has some special options for running on SSD?
actually, I haven't found any information about reiser 4 + SSD

dusanc · Post by **dusanc** » Wed Dec 29, 2010 9:29 am

I use Reiser4 on an SSD, only thing I did was that I alligned partition on SSD (there's a howto on forums), and I used cryptocompression

There is no special SSD magic

ssteinberg · Post by **ssteinberg** » Wed Dec 29, 2010 11:15 am

I am getting a G73JW notebook with a Crucial C300 SSD soon, so this is becoming interesting.
ext4 with discard still seems the stable option. I am willing to play around however. btrfs with ssd and compress mount opts was what I wanted to try. Any good reason to try reiser4 over btrfs?

kernelOfTruth · Post by **kernelOfTruth** » Wed Dec 29, 2010 1:55 pm

ssteinberg wrote:I am getting a G73JW notebook with a Crucial C300 SSD soon, so this is becoming interesting.
ext4 with discard still seems the stable option. I am willing to play around however. btrfs with ssd and compress mount opts was what I wanted to try. Any good reason to try reiser4 over btrfs?

yes:

it's tested over years and looks pretty stable and DOES NOT eat your data

btrfs now already has eaten my data at least 2-3 times

also if you're using dm-crypt or cryptsetup - there's some silent corruption going on with btrfs and no one knows why

there are way more - just read through the reiser4 threads and you'll know why

vacula · Post by **vacula** » Wed Dec 29, 2010 2:19 pm

kernelOfTruth wrote:
ssteinberg wrote:I am getting a G73JW notebook with a Crucial C300 SSD soon, so this is becoming interesting.
ext4 with discard still seems the stable option. I am willing to play around however. btrfs with ssd and compress mount opts was what I wanted to try. Any good reason to try reiser4 over btrfs?
yes:

...

@kernelOfTruth: can you give any recomendation for mount params for reiser4 on SSD? i.e. commit=??,noatime,...

kernelOfTruth · Post by **kernelOfTruth** » Wed Dec 29, 2010 2:47 pm

vacula wrote:
kernelOfTruth wrote:
ssteinberg wrote:I am getting a G73JW notebook with a Crucial C300 SSD soon, so this is becoming interesting.
ext4 with discard still seems the stable option. I am willing to play around however. btrfs with ssd and compress mount opts was what I wanted to try. Any good reason to try reiser4 over btrfs?
yes:

...
@kernelOfTruth: can you give any recomendation for mount params for reiser4 on SSD? i.e. commit=??,noatime,...

try experimenting with:

Code: Select all

noatime,nodiratime,tmgr.atom_max_flushers=30,tree.cbk_cache.nr_slots=32

or

Code: Select all

noatime,nodiratime,tmgr.atom_max_flushers=30,tree.cbk_cache.nr_slots=128

Code: Select all

mkfs.reiser4 -o create=ccreg40,compress=lzo1,formatting=smart

should give you nice speed and the advantage of compression and checksumming

if you have many more
* large files: formatting=extents
* small files: formatting=tails

vacula · Post by **vacula** » Wed Dec 29, 2010 2:55 pm

Thanks, kernelOfTruth!

It would be nice to try this out among interested people and share results here. Then we could discuss those "best options" and add new separate question to the FAQ.

@dusanc:
?

kernelOfTruth · Post by **kernelOfTruth** » Wed Dec 29, 2010 3:17 pm

vacula wrote:Thanks, kernelOfTruth!

It would be nice to try this out among interested people and share results here. Then we could discuss those "best options" and add new separate question to the FAQ.

@dusanc:
?

he probably means:

in theory/proactically you could go with the stock options

mkfs.reiser4 -o create=ccreg40,compress=lzo1

or

mkfs.reiser4 -o create=ccreg40,compress=gzip1

and noatime,nodiratime

for mount-options

(noatime implies nodiratime so you don't really need nodiratime - but I still add it)

I however have made the experience that sometimes, e.g. the maximal flushers are not being set correctly or working optimally (e.g. 0 should be unlimited but setting it to 30 seemingly gave me better results)

and therefore I'm setting them explicitly

vacula · Post by **vacula** » Wed Dec 29, 2010 3:37 pm

kernelOfTruth wrote:
vacula wrote:Thanks, kernelOfTruth!

It would be nice to try this out among interested people and share results here. Then we could discuss those "best options" and add new separate question to the FAQ.

@dusanc:
?
he probably means:
...

With that question mark I mean only a question to dusanc - whether he could add new question+answer about reiser 4 on SSD

Now it's time to experiment

dusanc · Post by **dusanc** » Wed Dec 29, 2010 10:53 pm

vacula wrote: With that question mark I mean only a question to dusanc - whether he could add new question+answer about reiser 4 on SSD

Now it's time to experiment

Q18 added

costel78 · Post by **costel78** » Tue Jan 04, 2011 8:55 am

AFAIK reiser4 does not support TRIM. That's why I use ext4 on my SSD. And there are no garbage collector on my Intel M25 80GB drive.
Am I wrong ? Should I reconsider using reiser4 which was the fastest filesystem I ever use ?

dusanc · Post by **dusanc** » Tue Jan 04, 2011 9:46 am

If you align your FS, use -noatime as you should do with any FS on SSD, thing is that good SSD controllers won't detoriate easily over time (like Intel or sandforce ones). Not using your SSD for portage, tmp, or swap helps too

And as R4 does a great job of packing small writes, and has low fragmetation, detoriation is slower still.
You can clear your SSD after few years when you reinstall, or you can use recent hdparm and wiper tool ( http://sourceforge.net/projects/hdparm/files/ ) to discard trash on unmounted partition. BUT BE CAREFUL! Only safe data is with paranoid backups done with tinfoil hat

TRIM discards sectors supplied to it that don't contain data, but if wrong sectors are supplied to it, it'll discard them and eat your data.
And I don't use it, so proceed with caution, or ask someone who has.

But if you really need automatic online trash collection and automatic online trim by FS alone, reiser4 doesn't do it

It relies on user space for it

costel78 · Post by **costel78** » Tue Jan 04, 2011 10:31 am

I think I'll try it. Any chances that R4 to be integrated into mainline kernel this year ?

dusanc · Post by **dusanc** » Tue Jan 04, 2011 10:41 am

costel78 wrote:I think I'll try it. Any chances that R4 to be integrated into mainline kernel this year ?

I don't believe think so, unless akpm or some distro pushes it.

one_and_only · Post by **one_and_only** » Tue Jan 04, 2011 11:51 am

I got zen-kernel 2.6.32-zen2 manually patched with latest Edward's patches and, AFAIR, problem with removing directories should be gone (and it seems it was with patches that are in zen, but I had other issues so I had to take latest), but when I tried to remove "long" patch:
/var/tmp/portage/www-client/chromium-10.0.612.1-r1/work/chromium-10.0.612.1/out/Release/obj/gen/chrome
I got:

Code: Select all

[67777.788667] WARNING: Cannot unlink 92436075 (-2)
[67777.816186] reiser4[rm(18937)]: reiser4_unlink_common (fs/reiser4/plugin/inode_ops.c:300)[nikita-3398]:

Anybody got that?

dusanc · Post by **dusanc** » Tue Jan 04, 2011 12:08 pm

one_and_only wrote:I got zen-kernel 2.6.32-zen2 manually patched with latest Edward's patches and, AFAIR, problem with removing directories should be gone (and it seems it was with patches that are in zen, but I had other issues so I had to take latest), but when I tried to remove "long" patch:
/var/tmp/portage/www-client/chromium-10.0.612.1-r1/work/chromium-10.0.612.1/out/Release/obj/gen/chrome
I got:
Code: Select all
[67777.788667] WARNING: Cannot unlink 92436075 (-2)
[67777.816186] reiser4[rm(18937)]: reiser4_unlink_common (fs/reiser4/plugin/inode_ops.c:300)[nikita-3398]:
Anybody got that?

2.6.32?

Maybe try with something more recent, vanilla kernels? 2.6.36?
Also fsck the partition.

dusanc · Post by **dusanc** » Wed Jan 05, 2011 11:00 am

Btw. latest .36 patch is from 27Dec2010 so download it if you used earlier versions from http://www.kernel.org/pub/linux/kernel/ ... 4-for-2.6/

costel78 · Post by **costel78** » Wed Jan 05, 2011 11:23 am

I'll restored one of my gentoo backup on a reiser4 separate partition.
For me, except portage sync, there are no seizable difference between btrfs and reiser4, of course, except benchmarks.
It an Intel M-25 80 GB drive. So, I'll remain to ext4 which is more mature that btrfs and does support trim. I appreciate almost risk free file-systems.

kernelOfTruth · Post by **kernelOfTruth** » Wed Jan 05, 2011 1:17 pm

costel78 wrote:I'll restored one of my gentoo backup on a reiser4 separate partition.
For me, except portage sync, there are no seizable difference between btrfs and reiser4, of course, except benchmarks.
It an Intel M-25 80 GB drive. So, I'll remain to ext4 which is more mature that btrfs and does support trim. I appreciate almost risk free file-systems.

if you had followed the linux-ext4 or linux-kernel/lkml mailing list you would have seen that ext4 is far more risky than reiser4

I'm not writing this to bash ext4 in favor of reiser4 (I'm myself using ext4 on many harddrive partitions) but there for example was a
risk of data-loss with the 2.6.37 kernel which meanwhile got fixed (2.6.36 being safe, >2.6.36 until 2.6.37-rc6)

also I wouldn't use trim - since from what I read it can lead to data-loss (don't ask for the reasons why it leads to data loss - I forgot them but they sounded conclusive)

so the best option most probably would be to use reiser4 with cryptcompress (either lzo or gzip) and besides that only some other safe mount-options
that I posted in reply to vacula's question

ext4 might be "stable" and in the mainline / Linus' tree but it undergoes some heavy fixing and patching ...

so it would be better to be safe than sorry - especially if you don't have backups or only do them seldom

one_and_only · Post by **one_and_only** » Wed Jan 05, 2011 3:06 pm

dusanc wrote: Maybe try with something more recent, vanilla kernels? 2.6.36?
Also fsck the partition.

I meant 2.6.36, sorry for typo. I patched kernel before 27th, so I'll try the the lastest. Yes, fsck always helps for that.
Do I still need reiser4-fix-entd_flush.patch? cause have that patch applied already and it seems that's the only difference that Edward has made:
http://marc.info/?l=reiserfs-devel&m=12 ... 504144&w=2
But stil, I'll give it a shot.

dusanc · Post by **dusanc** » Wed Jan 05, 2011 3:31 pm

one_and_only wrote:
dusanc wrote: Maybe try with something more recent, vanilla kernels? 2.6.36?
Also fsck the partition.
I meant 2.6.36, sorry for typo. I patched kernel before 27th, so I'll try the the lastest. Yes, fsck always helps for that.
Do I still need reiser4-fix-entd_flush.patch? cause have that patch applied already and it seems that's the only difference that Edward has made:
http://marc.info/?l=reiserfs-devel&m=12 ... 504144&w=2
But stil, I'll give it a shot.

Only get the latest patch from 27'th over vanilla 2.6.36, nothing else, and then report it please

Gentree · Post by **Gentree** » Fri Jan 07, 2011 5:01 pm

neunon wrote:Might be good to add that SystemRescueCD can be used if you want to set up a Gentoo install with the root FS being Reiser4.

Just a note that partedmagic now has R4 support.

costel78 · Post by **costel78** » Sat Jan 08, 2011 12:53 pm

kernelOfTruth wrote: if you had followed the linux-ext4 or linux-kernel/lkml mailing list you would have seen that ext4 is far more risky than reiser4

I'm not writing this to bash ext4 in favor of reiser4 (I'm myself using ext4 on many harddrive partitions) but there for example was a
risk of data-loss with the 2.6.37 kernel which meanwhile got fixed (2.6.36 being safe, >2.6.36 until 2.6.37-rc6)

also I wouldn't use trim - since from what I read it can lead to data-loss (don't ask for the reasons why it leads to data loss - I forgot them but they sounded conclusive)

so the best option most probably would be to use reiser4 with cryptcompress (either lzo or gzip) and besides that only some other safe mount-options
that I posted in reply to vacula's question

ext4 might be "stable" and in the mainline / Linus' tree but it undergoes some heavy fixing and patching ...

so it would be better to be safe than sorry - especially if you don't have backups or only do them seldom

Well, you are right.
But I DO have backups (weekly for my /home and /var/www) and monthly for entire Gentoo systems (two). And, since I own that SSD I use only gentoo-sources, no release candidate kernel so I feel

that my data are safe enough.

one_and_only · Post by **one_and_only** » Sun Jan 16, 2011 10:19 pm

dusanc wrote: Only get the latest patch from 27'th over vanilla 2.6.36, nothing else, and then report it please

I patched over zen, but seems to work fine

. Thanks!

kernelOfTruth · Post by **kernelOfTruth** » Mon Feb 14, 2011 4:01 pm

if you folks are having problems with fixing your filesystem

a (potential) fix has been posted for reiser4progs 1.0.7

:

http://marc.info/?l=reiserfs-devel&m=12 ... 519745&w=2

Reiser4 Gentoo FAQ [25Dec2016]

reiser4 and SSD