Comments on: Lessfs-1.0.4 is available for download.

By: Alex

Alex — Sun, 07 Mar 2010 09:18:19 +0000

Hi Mark,
New feature enabled now of course !! this is a must have

shame that i hadn’t seen the option before reporting information. But, in a way, this is how we learn how to use it.

By: Mark

Mark — Sun, 07 Mar 2010 08:41:28 +0000

Enabling transactions will provide protection against most cases of database corruption. I strongly recommend this new feature.

Groet,

Mark

By: Bas Bleeker

Bas Bleeker — Sun, 07 Mar 2010 08:15:13 +0000

That will be great.
And thank you for the elaboration on the extra files. I’ll keep them safe

Greetings, Bas

By: Mark

Mark — Sun, 07 Mar 2010 07:47:29 +0000

I’ll change the logging thing as soon as I have time.
About ‘damaged / missing databases’.

Some databases can be reconstructed, like hardlinks, symlinks, blockusage.
Others metdata, fileblock, blockdata can not be reconstructed when you delete them.

By: Bas Bleeker

Bas Bleeker — Sat, 06 Mar 2010 16:59:08 +0000

Hi Mark,

I just noticed the same logging thing as Alex talked about.
When I checked my syslog, I also noticed the “Last Used” and “Filesystem is clean” entries come with a critical severity. Seems more like an info or notice severity to me.
All in all the rest works great.

I have just one small question: Now that I have the volume running, I see a few databases, apart from the big one. You know like hardlinks and stuff.
These small files are needed I suppose, but what happens if they are gone? are they easy to rebuild?

Cheers, Bas

By: Hubert Kario

Hubert Kario — Sat, 06 Mar 2010 11:37:06 +0000

I’ve made a “shell script” to get the compression ratio and amount of deduplication from lessfs:

grep ‘lessfs\[8118\]’ /var/log/messages.log | grep -Eo ‘size .* bytes \: lzo compressed bytes .* and .* duplicate blocks’ | awk ‘ { SUM += $2 ; SUMCP += $8 ; DUP += $10 } END { print “total size ” SUM/1024/1024/1024 “GiB, compressed size ” SUMCP/1024/1024/1024 “GiB (ratio 1 : ” SUM/SUMCP “) with ” DUP ” duplicate blocks (” DUP*64/1024/1024 “GiB deduplicated)” }’

change lessfs\[8118\] to the one you have in use and the DUP*64 is for 64KiB block size, change it if you use different

By: Mark

Mark — Sat, 06 Mar 2010 09:37:11 +0000

The rollback logging is a bug.
You did not enable transactions.
See the second line of the logging

By: Hubert Kario

Hubert Kario — Fri, 05 Mar 2010 23:34:57 +0000

Great news!

I’ve been thinking about using lessfs together with Samba shadow copy support to give users a native and easy to use access to their backups, problem is, we need a fairly complex security model that needs ACLs just so users couldn’t access files they don’t normally have access to.

Would it be possible for you to add support for POSIX ACLs?
(the extended attributes would be nice too, but they are not critical)

Thank you for your work
Hubert

By: Alex

Alex — Fri, 05 Mar 2010 22:06:08 +0000

Well, the sync command made the changes are kept in the volume (don’t know if there’s a link) but the “rollback to” date information in the log is allways “Thu Jan 1 01:00:00 1970″. So i think it’s just something in the way logs are handled.

By: Alex

Alex — Fri, 05 Mar 2010 21:59:28 +0000

Hi mark, just a question, have tried to unplug a drive using a mounted volume off lessfs, and great, while remounting it gets back really quick.

But, what makes change on the rollback date ? here is still “Thu Jan 1 01:00:00 1970″, even after writing a file, unpluging drive, mouting it back again.

Mar 5 22:49:22 localhost lessfs[28892]: The selected data store is tokyocabinet.
Mar 5 22:49:22 localhost lessfs[28892]: Lessfs transaction support is disabled.
Mar 5 22:49:22 localhost lessfs[28892]: Lessfs uses a 24 bytes long hash.
Mar 5 22:49:22 localhost lessfs[28892]: Lessfs fsync does not sync the databases to the disk when fsync is called on an inode
Mar 5 22:49:22 localhost lessfs[28892]: cache 12288 data blocks
Mar 5 22:49:22 localhost lessfs[28892]: The tiger hash has been selected.
Mar 5 22:49:23 localhost lessfs[28896]: Lessfs has not been unmounted cleanly.
Mar 5 22:49:23 localhost lessfs[28896]: Rollback to : Thu Jan 1 01:00:00 1970

How can i set the new rollback point ? something like “sync” ?