Comments on: Lessfs-1.1.2 has been released.

By: Mark Ruijter

Mark Ruijter — Mon, 19 Jul 2010 12:36:57 +0000

Lessfs will truncate the databases in real time when transactions is disabled and the tc datastore is selected. It will reuse the deleted blocks when transactions are enable and the datastore is either tc or file_io. You can force the database to release deleted chunks with telnet localhost 100 > defrag
This will actually rebuild the whole database and is therefore very time consuming with a large dataset.

By: Pete

Pete — Mon, 19 Jul 2010 12:31:39 +0000

I had noticed the same thing. I think that it is supposed to release the blocks after a number of minutes (as defined in the config file). But in reality, I only saw it release the unused blocks after taking the service offline and running lessfsck.

By: Ulrich Laaser

Ulrich Laaser — Sun, 18 Jul 2010 03:42:32 +0000

OK. Im not longer trying it with Centos (because of requierements not meet).
I changed to Ubuntu Server10.04 and here lessfs is working almost fine.

I have some questions:

1.) about blockdata.tch:

After deleting all files in the lessfs filesystem blockdata.tch still has a size of 1,9GB (that is exactly the amount of my testfile)
Is this normal? What happens if i have an lessfs filesystem with 50GB (max size) and then erase about 25GB? Will i found a blockdata.tch with a size of 50GB?

2) Can i use lessfs now for normal fileserver storage in production or should i only use it for backup storage

3) If i use the lessfs filesystem as vmdk storage trough ietd or nfs (i have 2 machines each one with a size of 50GB, so i will save only 2 big vmdk files) what settings can you recomend me for use in lessfs.cfg and for mounting options.
4) make it sense to use deduplication with 2 vmdk files? (Does lessfs deduplicate inside an vmdk file?

By: Ulrich Laaser

Ulrich Laaser — Sat, 17 Jul 2010 22:06:13 +0000

Hi, im trying to install an configure lessfs in Centos5.5 but im not sure if im making something wrong. I installed tokyocabinet and fuse from source to meet the requierements found in line 7406 of configure. But i still getting errors about requierements not meet. I also dont know anything about setting up depFlags… (y tried to learn it using google, but there was no help..at the moment)

Maybe you can help me with some tipps? And if i have to use Ubuntu10.04 Server can you help me giving a help what i have to do for installing and configuring lessfs….

What i want to do is build a Linux Server (minimal install) acting as nfs server and using lessfs…

best regards
Ulrich

By: Fajar Priyanto

Fajar Priyanto — Fri, 16 Jul 2010 09:30:49 +0000

Thanks. 1.1.3 works fine on Ubuntu 10.04 fully updated ^^

By: Pete

Pete — Thu, 15 Jul 2010 17:21:32 +0000

It seems like /usr/bin/lessfs is the rc script, not the binary. Try reinstalling lessfs, then follow the above steps again, and then try to start it… that should work for you.

By: Fajar Priyanto

Fajar Priyanto — Thu, 15 Jul 2010 10:00:32 +0000

Additional info:
Ubuntu 10.04 fully updated
Same result using lessfs-1.1.1 and 1.1.2
Note: I use the libfuse2, libfuse-dev, and fuse-utils from Ubuntu repo, some howto in internet suggests to install them manually from the deb files.

By: Fajar Priyanto

Fajar Priyanto — Thu, 15 Jul 2010 09:46:13 +0000

Hi, I’ve installed a clean Ubuntu Server 10.04
Installation went very smoothly.

/data/db <– lessfs db dir
/data/backup <– actual backup dir

Issue: lessfs crashes:

Jul 15 17:42:30 backup6 lessfs[1107]: The selected data store is tokyocabinet.
Jul 15 17:42:30 backup6 lessfs[1107]: Lessfs transaction support is enabled.
Jul 15 17:42:30 backup6 lessfs[1107]: Hash MHASH_TIGER192 has been selected
Jul 15 17:42:30 backup6 lessfs[1107]: Lessfs uses a 24 bytes long hash.
Jul 15 17:42:30 backup6 lessfs[1107]: Automatic defragmentation is enabled.
Jul 15 17:42:30 backup6 lessfs[1107]: cache 2048 data blocks
Jul 15 17:42:30 backup6 lessfs[1110]: The filesystem is clean.
Jul 15 17:42:30 backup6 lessfs[1110]: Last used at : Thu Jul 15 17:40:09 2010
Jul 15 17:42:30 backup6 kernel: [ 676.053545] lessfs[1115]: segfault at c25fcaf0 ip 0804e6e1 sp 9e4a5320 error 7 in lessfs[8048000+16000]

Anything I can do to remedy it? Let me know if you need more info.
Thank you.

By: wxp

wxp — Thu, 15 Jul 2010 06:00:10 +0000

[root@Fedora-12-i386-DVD ~]# /usr/bin/lessfs /etc/lessfs.cfg /fuse/lessfs/
Usage: /usr/bin/lessfs {start|stop|restart}
[root@Fedora-12-i386-DVD ~]#

[root@Fedora-12-i386-DVD ~]# /usr/bin/lessfs restart /etc/lessfs.cfg /fuse/lessfs
Stopping lessfs:
Starting lessfs: Usage: /usr/bin/lessfs {start|stop|restart}

[root@Fedora-12-i386-DVD ~]#

I don’t why?

By: wxp

wxp — Thu, 15 Jul 2010 04:43:33 +0000

Hi Mark, I am sorry to trouble you!
I want to know what functions dose LessFS has? Read, Write and so on.
So far I have not found if LessFS has Backup function, and I want to know where is data dedup used? (write, backup or others), and where is
Tiger hash (thash(***)) used? (write, backup or others)
Thank you!