Why no creation date-stamp in ReiserFS and ext3?
http://en.wikipedia.org/wiki/Comparison_of_file_systems says that Reiser and ext do not support creation time-stamps. If this is true, why? If there's a reason for FAT etc to have creation time-stamps, then that same reason will apply to Reiser/ext too, no?
Shriramana Sharma wrote:
http://en.wikipedia.org/wiki/Comparison_of_file_systems says that Reiser and ext do not support creation time-stamps. If this is true, why?
If there's a reason for FAT etc to have creation time-stamps, then that same reason will apply to Reiser/ext too, no?
I haven't checked the URL to see quite what they mean, but if we are on the same wavelength, any file on any filesystem has a creation date and time and if necessary, you can "touch file" so it updates the date and time to now. # vi abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:39 abcd # touch abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:45 abcd Regards Sid. -- Sid Boyce ... Hamradio License G3VBV, Keen licensed Private Pilot Retired IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Specialist Microsoft Windows Free Zone - Linux used for all Computing Tasks
On 19 Aug 2005, sboyce@blueyonder.co.uk wrote:
I haven't checked the URL to see quite what they mean, but if we are on the same wavelength, any file on any filesystem has a creation date and time and if necessary, you can "touch file" so it updates the date and time to now.
That is the "last modified date and time (mtime)" which is different From what the op was originally asking. Charles -- "On a normal ascii line, the only safe condition to detect is a 'BREAK' - everything else having been assigned functions by Gnu EMACS." (By Tarl Neustaedter)
Um, guys, I'm confused. I'm pretty sure that ReiserFS (donno about ext3, long time since I used it) has the recently modified and recently accessed time stamps. Just verified it with a file (/etc/fstab to be precise) on my system. But there doesn't seem to be any file created stamp. This seems to bear out Wikipedia's statement that ReiserFS does not carry a file created stamp.
Shriramana Sharma wrote:
Um, guys, I'm confused. I'm pretty sure that ReiserFS (donno about ext3, long time since I used it) has the recently modified and recently accessed time stamps. Just verified it with a file (/etc/fstab to be precise) on my system. But there doesn't seem to be any file created stamp. This seems to bear out Wikipedia's statement that ReiserFS does not carry a file created stamp.
That appears to be the case. See /usr/src/linux/include/linux/reiserfs_fs.h and /usr/src/linux/include/linux/ext3_fs.h. Both define atime, mtime, and ctime, which can be obtained for any node using -printf arguments of find. While ctime is referred to as "creation time" in ext3_fs.h, it is referred to as "time inode (stat data) was last changed (except changes to sd_atime and sd_mtime)" in reiserfs_fs.h. It apparently functions as the latter on a Reiser FS. I have not checked on an ext3 filesystem.
On Friday, August 19, 2005 @ 3:46 AM, Sid Boyce wrote:
Shriramana Sharma wrote:
http://en.wikipedia.org/wiki/Comparison_of_file_systems says that Reiser and ext do not support creation time-stamps. If this is true, why?
If there's a reason for FAT etc to have creation time-stamps, then that same reason will apply to Reiser/ext too, no?
I haven't checked the URL to see quite what they mean, but if we are on the same wavelength, any file on any filesystem has a creation date and time and if necessary, you can "touch file" so it updates the date and time to now. # vi abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:39 abcd # touch abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:45 abcd
Regards Sid. -- Sid Boyce ... Hamradio License G3VBV, Keen licensed Private Pilot Retired IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Specialist Microsoft Windows Free Zone - Linux used for all Computing Tasks
But Sid, we're talking about a date that would NOT be replaced; i. e., it would continue to show the original creation date. To do that, you'd need 3 dates -- *) Creation -- Never modified after file was originally created *) Updated -- Modified any time the file is updated *) Accessed -- Modified any time the file was touched Greg Wallace
Greg Wallace wrote:
On Friday, August 19, 2005 @ 3:46 AM, Sid Boyce wrote:
Shriramana Sharma wrote:
http://en.wikipedia.org/wiki/Comparison_of_file_systems says that Reiser and ext do not support creation time-stamps. If this is true, why?
If there's a reason for FAT etc to have creation time-stamps, then that same reason will apply to Reiser/ext too, no?
I haven't checked the URL to see quite what they mean, but if we are on the same wavelength, any file on any filesystem has a creation date and time and if necessary, you can "touch file" so it updates the date and time to now. # vi abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:39 abcd # touch abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:45 abcd
Regards Sid. --
But Sid, we're talking about a date that would NOT be replaced; i. e., it would continue to show the original creation date. To do that, you'd need 3 dates --
*) Creation -- Never modified after file was originally created *) Updated -- Modified any time the file is updated *) Accessed -- Modified any time the file was touched
Greg Wallace
Thanks, I misread the question being unfamiliar with that other OS. Regards Sid. -- Sid Boyce ... Hamradio License G3VBV, Keen licensed Private Pilot Retired IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Specialist Microsoft Windows Free Zone - Linux used for all Computing Tasks
On Friday 19 August 2005 19:50, Greg Wallace wrote:
On Friday, August 19, 2005 @ 3:46 AM, Sid Boyce wrote:
Shriramana Sharma wrote:
http://en.wikipedia.org/wiki/Comparison_of_file_systems says that Reiser and ext do not support creation time-stamps. If this is true, why?
If there's a reason for FAT etc to have creation time-stamps, then that same reason will apply to Reiser/ext too, no?
I haven't checked the URL to see quite what they mean, but if we are on the same wavelength, any file on any filesystem has a creation date and time and if necessary, you can "touch file" so it updates the date and time to now. # vi abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:39 abcd # touch abcd # ls -l abcd -rw-r--r-- 1 root root 9 2005-08-19 12:45 abcd
Sid Boyce ... Hamradio License G3VBV, Keen licensed Private Pilot Retired IBM/Amdahl Mainframes and Sun/Fujitsu Servers Tech Support Specialist Microsoft Windows Free Zone - Linux used for all Computing Tasks
But Sid, we're talking about a date that would NOT be replaced; i. e., it would continue to show the original creation date. To do that, you'd need 3 dates --
*) Creation -- Never modified after file was originally created *) Updated -- Modified any time the file is updated *) Accessed -- Modified any time the file was touched
I looked at it from a different angle and I'm equally puzzled. I really did expect to find a "creation" timestamp and did not. kenjen@wolverine:~> touch abcd kenjen@wolverine:~> ls -l abcd -rw-r--r-- 1 kenjen users 0 2005-08-19 19:59 abcd kenjen@wolverine:~> stat abcd File: `abcd' Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: 305h/773d Inode: 7659 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 501/ kenjen) Gid: ( 100/ users) Access: 2005-08-19 19:59:14.697278000 -0400 Modify: 2005-08-19 19:59:14.697278000 -0400 Change: 2005-08-19 19:59:14.697278000 -0400 kenjen@wolverine:~> touch abcd kenjen@wolverine:~> stat abcd File: `abcd' Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: 305h/773d Inode: 7659 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 501/ kenjen) Gid: ( 100/ users) Access: 2005-08-19 20:00:42.138984840 -0400 Modify: 2005-08-19 20:00:42.138984840 -0400 Change: 2005-08-19 20:00:42.138984840 -0400 So, by default, touch touches everything by default. kenjen@wolverine:~> touch -a abcd kenjen@wolverine:~> stat abcd File: `abcd' Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: 305h/773d Inode: 7659 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 501/ kenjen) Gid: ( 100/ users) Access: 2005-08-19 20:05:15.189837000 -0400 Modify: 2005-08-19 20:00:42.138984000 -0400 Change: 2005-08-19 20:05:15.189474856 -0400 touch -a changed the "access" and the "change" time. kenjen@wolverine:~> touch -m abcd kenjen@wolverine:~> stat abcd File: `abcd' Size: 0 Blocks: 0 IO Block: 4096 regular empty file Device: 305h/773d Inode: 7659 Links: 1 Access: (0644/-rw-r--r--) Uid: ( 501/ kenjen) Gid: ( 100/ users) Access: 2005-08-19 20:05:15.189837000 -0400 Modify: 2005-08-19 20:06:41.439402000 -0400 Change: 2005-08-19 20:06:41.439362880 -0400 touch -m changed the "modify" and the "change" time. I guess from the behavior that "change" means any kind of examination made to the file. For some reason I really did expect to find a creation timestamp. Curious. man fstat() shows the following time values on a file: time_t st_atime; /* time of last access */ time_t st_mtime; /* time of last modification */ time_t st_ctime; /* time of last status change */ Huh. This I understand should not be filesystem specific. I never really bothered to look at it before. But, it appears creation timestamp is not a unix-y thing. Wonder what I was smoking that had me thinking there was a creation timestamp? So I looked it up and found: http://www.faqs.org/faqs/unix-faq/faq/part3/section-1.html 3.1) How do I find the creation time of a file? You can't - it isn't stored anywhere. Files have a last-modified time (shown by "ls -l"), a last-accessed time (shown by "ls -lu") and an inode change time (shown by "ls -lc"). The latter is often referred to as the "creation time" - even in some man pages - but that's wrong; it's also set by such operations as mv, ln, chmod, chown and chgrp. The man page for "stat(2)" discusses this. Well, that explains that I think.
participants (6)
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Charles philip Chan -
Gary Gapinski -
Greg Wallace -
Shriramana Sharma -
Sid Boyce -
Synthetic Cartoonz