Nilfs features
Hi,
I converted (backup/restore) my home directory onto nilfs2 to test it in anger (yes i know the caveats about it corrupting all my data, etc, but i'm willing to restore when required).
When restoring the data onto a nilfs2 filesystem there really is no requirement to have the checkpointing running as you have a good copy from your tar, cpio archive that you are restoring from. So is there a way to temporarily suspend checkpointing with a command and then restart it after the restore has completed ? I think this would be useful also for when you want to have a 'privacy' mode (like firefox/mozilla) where you can suspend checkpointing, start some confidential work, email, browsing etc, and then restart checkpointing and roll back to the previous state.
In addition to this there doesn't seem to be a way to delete a range of checkpoints. When i did my restore from my archive, i generated 700+ useless checkpoints which i had to delete one by one (in a script). It would be nice to have a 'rmcp 1-100' or 'rmcp -100' or 'rmcp 100-' to delete a checkpoint range, a start to end.
Also it seems for home directories, a 5 second checkpointing seems exessive. In 14hrs i have 10,000 checkpoints (even when seemingly idle with mozilla page refreshes, dovecot index files updates for email, etc).
home:~$ uptime
13:35:09 up 14:29, 7 users, load average: 0.85, 1.76, 2.07
home:~$ lscp|tail
10342 2009-05-25 13:34:31 cp i 6698 323163
10343 2009-05-25 13:34:36 cp - 6761 323163
10344 2009-05-25 13:34:41 cp i 6702 323163
10345 2009-05-25 13:34:45 cp - 29 323163
10346 2009-05-25 13:34:46 cp i 6679 323163
10347 2009-05-25 13:34:51 cp i 6669 323163
10348 2009-05-25 13:34:56 cp i 6675 323163
10349 2009-05-25 13:35:01 cp i 6676 323163
10350 2009-05-25 13:35:06 cp i 6649 323163
10351 2009-05-25 13:35:11 cp i 6679 323163It would also be nice to change the cp/clean interval without editing the conf file, perhaps during the nite we can had different checkpoint intervals and during work a smaller cp interval.
Finally instead of having 5 commands, it'd be nice to have once command with different options (like zfs). So instead have
. nilfs checkpoint
. nilfs snapshot
. nilfs remove
. nilfs list
. nilfs suspend
. nilfs restart
etc...
All seems to be working fine so far, so take this as constructive comments.
Cheers
Dave
A message that is not in the archive (sent off-list or not yet received): 4A1A68E6.50905-/[email protected]
Hi,
Quoted 5 lines · Dave
Hi,
I converted (backup/restore) my home directory onto nilfs2 to test it in anger (yes i know the caveats about it corrupting all my data, etc, but i'm willing to restore when required).
What happened to you ?
Anyway, thanks for your interest in nilfs.
(yeah, I'm trying my best, but I keenly feel it's really tough to keep the reliability of the filesystem. so, please remember the caveat.)
Quoted 3 lines
When restoring the data onto a nilfs2 filesystem there really is no requirement to have the checkpointing running as you have a good copy from your tar, cpio archive that you are restoring from.
Yes, definitely.
Quoted 6 lines
So is there a way to temporarily suspend checkpointing with a command and then restart it after the restore has completed ? I think this would be useful also for when you want to have a 'privacy' mode (like firefox/mozilla) where you can suspend checkpointing, start some confidential work, email, browsing etc, and then restart checkpointing and roll back to the previous state.
Is your demand rollback feature or some kind of silent (or invalid by default) checkpointing, or both ?
The checkpointing is essential for nilfs, every write on nilfs requires creating a checkpoint by its nature. But I think it's possible to make them inaccessible by default.
Rollback is worth considering. Yes, I agree. it actually makes the recovery of filesystem state smarter.
It even could be a first step toward realization of the remote replication (as discussed before in this mailing list).
Quoted 5 lines
In addition to this there doesn't seem to be a way to delete a range of checkpoints. When i did my restore from my archive, i generated 700+ useless checkpoints which i had to delete one by one (in a script). It would be nice to have a 'rmcp 1-100' or 'rmcp -100' or 'rmcp 100-' to delete a checkpoint range, a start to end.
Okay, I'll take in this in some form.
Quoted 19 lines
Also it seems for home directories, a 5 second checkpointing seems exessive. In 14hrs i have 10,000 checkpoints (even when seemingly idle with mozilla page refreshes, dovecot index files updates for email, etc).
home:~$ uptime 13:35:09 up 14:29, 7 users, load average: 0.85, 1.76, 2.07 home:~$ lscp|tail 10342 2009-05-25 13:34:31 cp i 6698 323163 10343 2009-05-25 13:34:36 cp - 6761 323163 10344 2009-05-25 13:34:41 cp i 6702 323163 10345 2009-05-25 13:34:45 cp - 29 323163 10346 2009-05-25 13:34:46 cp i 6679 323163 10347 2009-05-25 13:34:51 cp i 6669 323163 10348 2009-05-25 13:34:56 cp i 6675 323163 10349 2009-05-25 13:35:01 cp i 6676 323163 10350 2009-05-25 13:35:06 cp i 6649 323163 10351 2009-05-25 13:35:11 cp i 6679 323163
Quoted 3 lines
It would also be nice to change the cp/clean interval without editing the conf file, perhaps during the nite we can had different checkpoint intervals and during work a smaller cp interval.
Checkpoint creation is essential to nilfs writes, so this seems to be difficult without introducing some kind of invisible checkpoint. (checkpoint removal is much easier, but I understood what you want
slightly differs from such external )
I think it needs care because the feature partially invalidate what the nilfs stands for. Maybe 5 seconds checkpoining should be remained as default. But some flexiblity might well be allowed as you pointed out.
Supporting method changing cleaning interval without editing the conf file, sounds reasonable (yes, sorry for inconvenience).
Quoted 10 lines
Finally instead of having 5 commands, it'd be nice to have once command with different options (like zfs). So instead have
. nilfs checkpoint
. nilfs snapshot
. nilfs remove
. nilfs list
. nilfs suspend
. nilfs restart
etc...
Yeah, I agree reorganizing commands into one 'nilfs' command is preferable. Well, I'll add this to the todo items on the site.
I think it would be nice if the old commands are available through symbolic links to this unified command according to user's predilection.
Quoted 4 lines
All seems to be working fine so far, so take this as constructive comments.
Cheers
Dave
Thank you for many productive comments!
Regards,
Ryusuke Konishi
A message that is not in the archive (sent off-list or not yet received): [email protected]
Quoted 9 lines · Ryusuke Konishi
Quoted 4 lines
I converted (backup/restore) my home directory onto nilfs2 to test it in anger (yes i know the caveats about it corrupting all my data, etc, but i'm willing to restore when required).
What happened to you ?
Anyway, thanks for your interest in nilfs.
(yeah, I'm trying my best, but I keenly feel it's really tough to keep the reliability of the filesystem. so, please remember the caveat.)
Yes, understood very well, but you also you underestimate your code ;-) Please keep up the good work. The free world has been waiting for this kind of filesystem for a while.
Quoted 9 lines
Quoted 6 lines
So is there a way to temporarily suspend checkpointing with a command and then restart it after the restore has completed ? I think this would be useful also for when you want to have a 'privacy' mode (like firefox/mozilla) where you can suspend checkpointing, start some confidential work, email, browsing etc, and then restart checkpointing and roll back to the previous state.
Is your demand rollback feature or some kind of silent (or invalid by default) checkpointing, or both ?
No, not demanding anything. Requesting it as a feature. While your design has a very crucial use-case of constant checkpointing, there is also a use-case to *suspend* checkpointing (or enable it on demand only). As mentioned in my previous example, when restoring to a filesystem, or even installing new software, it is extremely unlikely that you would want a to go back to a point *inbetween* the time you started the install/restore to the time it completed. Say for example you are installing a new version of Openoffice which installs
home:/opt/openoffice.org$ find . ! -type d |wc -l
41004000 odd files. For sure if the software didn't work, crashed, was buggy, i would go back completely to the pre-install state and would never need any intervening checkpoint. In this case i would suspend checkpointing before installing (which may by default create a snapshot), and then i'd restart the constant checkpointing after i'd finished the install/restore. Please note, i am not comparing nilfs to zfs, but zfs doesn't have constant cp (i think) but does have the feature i mention, i.e you take snapshots when needed (perhaps via a cron job daily, monthly, weekly)
Quoted 9 lines
The checkpointing is essential for nilfs, every write on nilfs requires creating a checkpoint by its nature. But I think it's possible to make them inaccessible by default.
Rollback is worth considering. Yes, I agree. it actually makes the recovery of filesystem state smarter.
It even could be a first step toward realization of the remote replication (as discussed before in this mailing list).
Yes, after i posted, i went back on the mailing list and seen the request already. Sorry for requesting the feature again.
Quoted 4 lines
I think it needs care because the feature partially invalidate what the nilfs stands for. Maybe 5 seconds checkpoining should be remained as default. But some flexiblity might well be allowed as you pointed out.
Agreed, but it wouldn't invalidate what nilfs stood for, it would enhance it, but it is your code, so it's your right to decide and i respect that.
Quoted 2 lines
Supporting method changing cleaning interval without editing the conf file, sounds reasonable (yes, sorry for inconvenience).
No need to apologize.
Quoted 11 lines
Quoted 10 lines
Finally instead of having 5 commands, it'd be nice to have once command with different options (like zfs). So instead have
. nilfs checkpoint
. nilfs snapshot
. nilfs remove
. nilfs list
. nilfs suspend
. nilfs restart
etc...
Quoted 2 lines
Yeah, I agree reorganizing commands into one 'nilfs' command is preferable. Well, I'll add this to the todo items on the site.
Thanks (my /usr/bin directory seems to be growing exponentially).
Quoted 3 lines
I think it would be nice if the old commands are available through symbolic links to this unified command according to user's predilection.
Agreed, but why have 5 commands and 5 manpages when you can have 1 of each ;-). I think users will get used to it and eventually you can delete the symlinks.
Thanks for your responses.
D
Hi,
Quoted 9 lines · Ryusuke Konishi
Hi,
Quoted 5 lines · Dave
In addition to this there doesn't seem to be a way to delete a range of checkpoints. When i did my restore from my archive, i generated 700+ useless checkpoints which i had to delete one by one (in a script). It would be nice to have a 'rmcp 1-100' or 'rmcp -100' or 'rmcp 100-' to delete a checkpoint range, a start to end.
Okay, I'll take in this in some form.
For the moment, I've added this feature and pushed it into the git tree.
(Instead of '1-100', '-100', or '10..', I took notation like '1..100',
'..100', or '10..' respectively, according to the git tool)
If you would like to try it soon, please see
for download/build information.
I'll include it in the next release of the utility package.
Cheers,
Ryusuke Konishi
A message that is not in the archive (sent off-list or not yet received): [email protected]
Quoted 17 lines · Ryusuke Konishi
Hi,
Quoted 8 lines · Ryusuke Konishi
Hi,
Quoted 5 lines · Dave
In addition to this there doesn't seem to be a way to delete a range of checkpoints. When i did my restore from my archive, i generated 700+ useless checkpoints which i had to delete one by one (in a script). It would be nice to have a 'rmcp 1-100' or 'rmcp -100' or 'rmcp 100-' to delete a checkpoint range, a start to end.
Okay, I'll take in this in some form.
For the moment, I've added this feature and pushed it into the git tree.
(Instead of '1-100', '-100', or '10..', I took notation like '1..100',
'..100', or '10..' respectively, according to the git tool)
Quoted 8 lines
If you would like to try it soon, please see
for download/build information.
I'll include it in the next release of the utility package.
Hi Ryusuke,
I've tried this and it seems to work perfectly. Thanks for the quick feature addition.
It seems that i still have to wait for cleanerd to kick in to reclaim the space even though i clearly cannot get to a checkpoint i've just deleted. I believe we should reclaim immediately (but perhaps this is harder to implement)...
bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb2 39G 9.0G 28G 25% /home
bash-3.2# cp /shared/1gb .
bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb2 39G 10G 27G 28% /home
bash-3.2# lscp | tail
155133 2009-06-02 12:12:27 cp i 6662 253255
155134 2009-06-02 12:12:29 cp - 35 253255
155135 2009-06-02 12:12:32 cp i 6622 253255
155136 2009-06-02 12:12:37 cp i 6587 253255
155137 2009-06-02 12:12:42 cp i 6654 253255
155138 2009-06-02 12:12:47 cp i 6744 253255
155139 2009-06-02 12:12:52 cp i 6524 253255
155140 2009-06-02 12:12:57 cp i 6762 253255
155141 2009-06-02 12:13:02 cp i 6670 253255
155142 2009-06-02 12:13:07 cp - 6748 253255bash-3.2# rm 1gb
bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb2 39G 10G 27G 28% /home
bash-3.2# lscp|tail
155151 2009-06-02 12:13:29 cp - 35 253188
155152 2009-06-02 12:13:35 cp - 237 253229
155153 2009-06-02 12:13:37 cp - 6334 253238
155154 2009-06-02 12:13:42 cp - 8380 253255
155155 2009-06-02 12:13:47 cp i 7987 253255
155156 2009-06-02 12:13:52 cp i 3743 253255
155157 2009-06-02 12:13:57 cp i 8092 253255
155158 2009-06-02 12:14:02 cp i 7991 253255
155159 2009-06-02 12:14:07 cp i 7986 253255
155160 2009-06-02 12:14:12 cp - 9129 253254
bash-3.2# rmcp ..155160
bash-3.2# lscp|tail
CNO DATE TIME MODE FLG NBLKINC ICNT
155161 2009-06-02 12:14:17 cp i 6839 253254
155162 2009-06-02 12:14:22 cp i 7012 253254
155163 2009-06-02 12:14:27 cp - 6886 253255
155164 2009-06-02 12:14:29 cp - 51 253254
155165 2009-06-02 12:14:32 cp i 6737 253254
155166 2009-06-02 12:14:37 cp i 2618 253254bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb2 39G 10G 27G 28% /home
much appreciated.
Dave
A message that is not in the archive (sent off-list or not yet received): 4A24E100.8040204-/[email protected]
Hi,
Quoted 29 lines · Dave
Quoted 17 lines · Ryusuke Konishi
Hi,
Quoted 8 lines · Ryusuke Konishi
Hi,
Quoted 5 lines · Dave
In addition to this there doesn't seem to be a way to delete a range of checkpoints. When i did my restore from my archive, i generated 700+ useless checkpoints which i had to delete one by one (in a script). It would be nice to have a 'rmcp 1-100' or 'rmcp -100' or 'rmcp 100-' to delete a checkpoint range, a start to end.
Okay, I'll take in this in some form.
For the moment, I've added this feature and pushed it into the git tree.
(Instead of '1-100', '-100', or '10..', I took notation like '1..100',
'..100', or '10..' respectively, according to the git tool)Quoted 8 lines
If you would like to try it soon, please see
for download/build information.
I'll include it in the next release of the utility package.
Hi Ryusuke,
Quoted 7 lines
I've tried this and it seems to work perfectly. Thanks for the quick feature addition.
It seems that i still have to wait for cleanerd to kick in to reclaim the space even though i clearly cannot get to a checkpoint i've just deleted. I believe we should reclaim immediately (but perhaps this is harder to implement)...
Yes, checkpoint removal by rmcp does not mean reclamation; operation of the cleanerd is necessary to that end.
Well, I thought the (plain) checkpoints are equivalent to deleted ones. But the checkpoint removal makes a differece in that deleted checkpoints become unprotected by the protection period.
Hmm, indeed we need some change on the cleanerd.
At least the cleanerd should be notified about the removal and revaluate the need of reclamation.
Thanks you for feedback.
Regards,
Ryusuke Konishi
Quoted 50 lines
bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb239G 9.0G 28G 25% /home
bash-3.2# cp /shared/1gb .
bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb239G 10G 27G 28% /home
bash-3.2# lscp | tail155133 2009-06-02 12:12:27 cp i 6662 253255 155134 2009-06-02 12:12:29 cp - 35 253255 155135 2009-06-02 12:12:32 cp i 6622 253255 155136 2009-06-02 12:12:37 cp i 6587 253255 155137 2009-06-02 12:12:42 cp i 6654 253255 155138 2009-06-02 12:12:47 cp i 6744 253255 155139 2009-06-02 12:12:52 cp i 6524 253255 155140 2009-06-02 12:12:57 cp i 6762 253255 155141 2009-06-02 12:13:02 cp i 6670 253255 155142 2009-06-02 12:13:07 cp - 6748 253255bash-3.2# rm 1gb
bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb239G 10G 27G 28% /home
bash-3.2# lscp|tail155151 2009-06-02 12:13:29 cp - 35 253188 155152 2009-06-02 12:13:35 cp - 237 253229 155153 2009-06-02 12:13:37 cp - 6334 253238 155154 2009-06-02 12:13:42 cp - 8380 253255 155155 2009-06-02 12:13:47 cp i 7987 253255 155156 2009-06-02 12:13:52 cp i 3743 253255 155157 2009-06-02 12:13:57 cp i 8092 253255 155158 2009-06-02 12:14:02 cp i 7991 253255 155159 2009-06-02 12:14:07 cp i 7986 253255 155160 2009-06-02 12:14:12 cp - 9129 253254 bash-3.2# rmcp ..155160 bash-3.2# lscp|tail CNO DATE TIME MODE FLG NBLKINC ICNT 155161 2009-06-02 12:14:17 cp i 6839 253254 155162 2009-06-02 12:14:22 cp i 7012 253254 155163 2009-06-02 12:14:27 cp - 6886 253255 155164 2009-06-02 12:14:29 cp - 51 253254 155165 2009-06-02 12:14:32 cp i 6737 253254 155166 2009-06-02 12:14:37 cp i 2618 253254bash-3.2# df -h .
Filesystem Size Used Avail Use% Mounted on/dev/sdb239G 10G 27G 28% /homemuch appreciated.
Dave