Free space left
How can I detect how much free space is left on a btrfs-volume? As I read (and learned in practice!) df reports cannot be trusted if used on btrfs-volumes. Greetings, Michael -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
worse than expected compression ratios with -o compress
I have a mysql database which consists of hundreds of millions, if not billions of Usenet newsgroup headers. This data should be highly compressable, so I put the mysql data directory on a btrfs filesystem mounted with the compress option: /dev/sdi on /var/news/mysql type btrfs (rw,noatime,compress,noacl) However, I'm not seeing the kind of compression ratios that I would expect with this type of data. FYI, all my tests are using Linux 2.6.32.3. Here's my current disk usage: FilesystemSize Used Avail Use% Mounted on /dev/sdi 302G 122G 181G 41% /var/news/mysql and here's the actual size of all files: delta-9 mysql # pwd /var/news/mysql delta-9 mysql # du -h --max-depth=1 747K./mysql 0 ./test 125G./urd 125G. delta-9 mysql # As you can see, I am only shaving off 3 gigs out of 125 gigs worth of what should be very compressable data. The compressed data ends up being around 98% the size of the original data. To contrast, rzip can compress a database dump of this data to around 7% of its original size. This is an older database dump, which is why it is smaller. Before: -rw--- 1 root root 69G 2010-01-15 14:55 mysqlurdbackup.2010-01-15 and after: -rw--- 1 root root 5.2G 2010-01-16 05:34 mysqlurdbackup.2010-01-15.rz Of course it took 15 hours to compress the data, and btrfs wouldn't be able to use rzip for compression anyway. However, I still would expect to see better compression ratios than 98% on such data. Are there plans to implement a better compression algorithm? Alternatively, is there a way to tune btrfs compression to achieve better ratios? thanks, Jim Faulkner Please CC my e-mail address on any replies. -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Free space left
On Saturday 16 January 2010, Michael Niederle wrote: How can I detect how much free space is left on a btrfs-volume? As I read (and learned in practice!) df reports cannot be trusted if used on btrfs-volumes. Try btrfs-show $ btrfs-show Label: bar uuid: ec2918cd-ad47-4eac-9e85-5604b02fd922 Total devices 1 FS bytes used 302.25MB devid1 size 964.81MB used 614.50MB path /dev/sdc1 Label: debian-root uuid: 6e2a647f-5da2-4bd0-a7d7-9b13d13a47cc Total devices 1 FS bytes used 23.52GB devid1 size 232.11GB used 118.03GB path /dev/sdc3 Btrfs Btrfs v0.19 BR G.Baroncelli -- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) kreij...@inwind.it Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512 -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Free space left
Hi, Goffredo! Try btrfs-show Thanks for your advice! btrfs-show works but it displays a lot of error message for non-btrfs devices: btrfs-show failed to read /dev/sdg failed to read /dev/sdg1 failed to read /dev/sdg2 failed to read /dev/sdg3 failed to read /dev/sdg4 failed to read /dev/md1 failed to read /dev/fd0 failed to read /dev/fd0u1440 failed to read /dev/fd1 failed to read /dev/hda failed to read /dev/hda1 failed to read /dev/hda10 failed to read /dev/hda11 failed to read /dev/hda12 ... failed to read /dev/sr0 failed to read /dev/sr1 failed to read /dev/sr2 failed to read /dev/sr3 ... Label: Alpha4 uuid: 63b82dad-ed81-41f4-910f-7b358ceb77ba Total devices 1 FS bytes used 11.81GB devid1 size 20.01GB used 20.01GB path /dev/sda3 Btrfs v0.19-4-gab8fb4c Even if I try btrfs-show /dev/sda3 I get the same output. Greetings, Michael -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Free space left
On Saturday 16 January 2010, you (Dipl.-Ing. Michael Niederle) wrote: Hi, Goffredo! Try btrfs-show Thanks for your advice! btrfs-show works but it displays a lot of error message for non-btrfs devices: btrfs-show failed to read /dev/sdg failed to read /dev/sdg1 failed to read /dev/sdg2 failed to read /dev/sdg3 failed to read /dev/sdg4 failed to read /dev/md1 failed to read /dev/fd0 failed to read /dev/fd0u1440 failed to read /dev/fd1 failed to read /dev/hda failed to read /dev/hda1 failed to read /dev/hda10 failed to read /dev/hda11 failed to read /dev/hda12 ... failed to read /dev/sr0 failed to read /dev/sr1 failed to read /dev/sr2 failed to read /dev/sr3 ... Label: Alpha4 uuid: 63b82dad-ed81-41f4-910f-7b358ceb77ba Total devices 1 FS bytes used 11.81GB devid1 size 20.01GB used 20.01GB path /dev/sda3 Btrfs v0.19-4-gab8fb4c Even if I try btrfs-show /dev/sda3 I get the same output. Greetings, Michael Yes they search in every block devices a btrfs file-system. It may be smarter/faster skipping the floppy and the cd-rom.. BR G.Baroncelli -- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) kreijackATinwind.it Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512 -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Free space left
Goffredo Baroncelli wrote: Try btrfs-show Ok: $ mount /dev/sdc on /media/452f782b-738a-4699-abfa-588eecab07ea type btrfs (rw,nosuid,nodev,uhelper=devkit) $ df /dev/sdc 932G 6.7G 925G 1% /media/452f782b-738a-4699-abfa-588eecab07ea $ btrfs-show failed to read /dev/sdb1 failed to read /dev/sdc failed to read /dev/sdb failed to read /dev/sda5 failed to read /dev/sda1 failed to read /dev/sda6 failed to read /dev/sda2 failed to read /dev/sda failed to read /dev/sr0 failed to read /dev/loop1 failed to read /dev/ram2 failed to read /dev/ram10 failed to read /dev/ram11 failed to read /dev/loop7 failed to read /dev/ram1 failed to read /dev/loop0 failed to read /dev/loop5 failed to read /dev/loop2 failed to read /dev/loop3 failed to read /dev/loop4 failed to read /dev/loop6 failed to read /dev/ram12 failed to read /dev/ram4 failed to read /dev/ram13 failed to read /dev/ram5 failed to read /dev/ram8 failed to read /dev/ram14 failed to read /dev/ram15 failed to read /dev/ram0 failed to read /dev/ram3 failed to read /dev/ram6 failed to read /dev/ram9 failed to read /dev/ram7 Btrfs Btrfs v0.19 The drive used is a Seagate FreeAgent 1Tb USB drive under Ubuntu 9.10 $ uname -a Linux ebrostig-laptop 2.6.31-18-generic-pae #55-Ubuntu SMP Fri Jan 8 16:13:23 UTC 2010 i686 GNU/Linux Erik -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Free space left
On Saturday 16 January 2010, you (Svein Erik Brostigen) wrote: Goffredo Baroncelli wrote: Try btrfs-show Ok: $ mount /dev/sdc on /media/452f782b-738a-4699-abfa-588eecab07ea type btrfs (rw,nosuid,nodev,uhelper=devkit) $ df /dev/sdc 932G 6.7G 925G 1% /media/452f782b-738a-4699-abfa-588eecab07ea $ btrfs-show failed to read /dev/sdb1 failed to read /dev/sdc ^ It seems that you don't have the right to read /dev/sdc. Retry as super user. [...] Btrfs Btrfs v0.19 The drive used is a Seagate FreeAgent 1Tb USB drive under Ubuntu 9.10 $ uname -a Linux ebrostig-laptop 2.6.31-18-generic-pae #55-Ubuntu SMP Fri Jan 8 16:13:23 UTC 2010 i686 GNU/Linux Erik -- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) kreij...@inwind.it Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512 -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Free space left
On Saturday 16 January 2010, Mathieu Chouquet-Stringer wrote: Hello, kreij...@gmail.com (Goffredo Baroncelli) writes: Try btrfs-show [...] How do you read this then: Label: none uuid: 27fafa43-7ad0-4e8a-ada8-36f73ef8984c Total devices 2 FS bytes used 79.63GB devid2 size 111.79GB used 111.01GB path /dev/sdb devid1 size 111.79GB used 111.03GB path /dev/sda I'm pretty sure I created this fs with -d raid1 -m raid1! Speaking of which, is there a way to read a FS configuration: how can I tell this FS really uses raid1 for both data and metadata? Even tough the raid mode is set per filesystem, btrfs has (will have) the capability to set the raid level per file. So it is no simple to estimate the free space: if every file is raid1 the real free space is half of the physical free space. But if some file are in raid1 (for examples /etc) and others are in raid0 (for example the ones under /usr which may be re-downloaded) the used space and the free space are difficult to estimate. There are some efforts to fix this kind of situation (see the thread [PATCH] Btrfs-progs: add btrfsctl -i to print space info). The used column is surprising: if it's a mirror why 111.01 and 111.03? And why all the space is being used anyway: I mean what's the difference between the 79.63GB and 111.0[13]? And the output of df is confusing too: /dev/sdb 234441648 83501968 150939680 36% /space It's reporting twice the total space but I think I remember looking it up and that should be fixed in a future kernel version. -- Mathieu Chouquet-Stringer mchou...@free.fr The sun itself sees not till heaven clears. -- William Shakespeare -- -- gpg key@ keyserver.linux.it: Goffredo Baroncelli (ghigo) kreijackATinwind.it Key fingerprint = 4769 7E51 5293 D36C 814E C054 BF04 F161 3DC5 0512 -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Free space left
Hello, kreij...@gmail.com (Goffredo Baroncelli) writes: Try btrfs-show [...] How do you read this then: Label: none uuid: 27fafa43-7ad0-4e8a-ada8-36f73ef8984c Total devices 2 FS bytes used 79.63GB devid2 size 111.79GB used 111.01GB path /dev/sdb devid1 size 111.79GB used 111.03GB path /dev/sda I'm pretty sure I created this fs with -d raid1 -m raid1! Speaking of which, is there a way to read a FS configuration: how can I tell this FS really uses raid1 for both data and metadata? The used column is surprising: if it's a mirror why 111.01 and 111.03? And why all the space is being used anyway: I mean what's the difference between the 79.63GB and 111.0[13]? And the output of df is confusing too: /dev/sdb 234441648 83501968 150939680 36% /space It's reporting twice the total space but I think I remember looking it up and that should be fixed in a future kernel version. -- Mathieu Chouquet-Stringer mchou...@free.fr The sun itself sees not till heaven clears. -- William Shakespeare -- -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
btrfsck segmentation fault
Hello, when trying to btrfsck my filesystem, I got the following error: # btrfsck /dev/sda7 parent transid verify failed on 13785038848 wanted 45848 found 45839 Segmentation fault Crash occurs at extent-tree.c:find_first_block_group when it gets: leaf = path-nodes[0]; after that btrfs_header_nritems dereferences the leaf unconditionally: struct btrfs_header *h = (struct btrfs_header *)leaf-data; Any thoughts on how to make it succeed? Thank you, André -- To unsubscribe from this list: send the line unsubscribe linux-btrfs in the body of a message to majord...@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html
