similar to: Re: Mis-Design of Btrfs?

This was a request from the systemd guys. They need a quick and easy way to get all devices attached to a Btrfs filesystem in order to check if any of the disks are SSD for...something, I didn''t ask :). I''ve tested this with the btrfs-progs patch that accompanies this patch. Thanks, Signed-off-by: Josef Bacik <josef@redhat.com> --- fs/btrfs/ioctl.c | 64

Hello, I''m testing Btrfs RAID1 feature on 3 disks of ~10GB. Last one is not exactly 10GB (would be too easy). About the test machine, it''s a kvm vm running an up-to-date archlinux with linux 3.7 and btrfs-progs 0.19.20121005. #uname -a Linux seblu-btrfs-1 3.7.0-1-ARCH #1 SMP PREEMPT Tue Dec 11 15:05:50 CET 2012 x86_64 GNU/Linux Filesystem was created with : # mkfs.btrfs -L

Dear all, While going through the archived mailing list and crawling along the wiki I didn''t find any clues if there would be any optimizations in Btrfs to make efficient use of functions and features that today exist on enterprise class storage arrays. One exception to that was the ssd option which I think can make a improvement on read and write IO''s however when attached to

I think it depends on who you ask. Facebook and Netflix are using it extensively in production: https://www.linux.com/news/learn/intro-to-linux/how-facebook-uses-linux-and-btrfs-interview-chris-mason Though they have the in-house kernel engineering resources to troubleshoot problems. When I see quotes like this [1] on the product's WIKI: "The parity RAID code has multiple serious

Hi! I recently tried to mount a filesystem in RAID1 mode using loopback devices. I followed the instructions at [1]. Here''s exactly what I''ve done: $ dd if=/dev/zero of=raid1_0.img bs=1M count=500 $ dd if=/dev/zero of=raid1_1.img bs=1M count=500 $ mkfs.btrfs -m raid1 -d raid1 raid1_0.img raid1_1.img $ losetup /dev/loop0 raid1_0.img $ losetup /dev/loop1 raid1_1.img $ mount -t

First off, thanks for an awesome file system, it is working well for my purposes of compressing a filesystem on a small VPS. Woot! I thought I''d call out a few things (in the hopes of spurring improvements) I''d seen about btrfs (in case they weren''t common knowledge...):

I have a 4 device volume with raid5 - trying to remove one of the devices (plenty of free space) and I get an almost immediate segfault. Scrub shows no errors, repair show space cache invalid but nothing else (I remounted with clear cache to be safe). Lots of corrupt on bdev (for 3 out of 4 drives), but I have no file access issues that I know of. Thanks! Output below:

Hi, Are SQLite users that are worried about losing data that has been committed (fsynced) better off setting data=journal than data=ordered (or even data=writeback)? The context is trying to reduce the number of writes to a flash file-system without sacrificing data integrity in the event of a power failure or OS crash. Thanks, Dan Kennedy.

Hallo, linux-btrfs, First I create an array of 2 disks with mkfs.btrfs -d raid0 -m raid1 /dev/sdb1 /dev/sdd1 and mount it at /srv/MM. Then I fill it with about 1,6 TByte. And then I add /dev/sde1 via btrfs device add /dev/sde1 /srv/MM btrfs filesystem balance /srv/MM (it run about 20 hours) Then I work on it, copy some new files, delete some old files - all works well. Only df

I have been trying to figure out whether I can enable write caching on my PATA hard drives (WD3200JB) and have fsync not return until data is safely on the platters. I am also running software raid. This is currently on FC5 (though soon to be FC6) with a 2.6.18 kernel. >From snippets I have found on the net, it looks like write barriers are pushed down through software raid when using raid 1.

Hiya, is there any recommendation out there to setup a btrfs FS on top of hardware or software raid5 or raid6 wrt stripe/stride alignment? From mkfs.btrfs, it doesn''t look like there''s much that can be adjusted that would help, and what I''m asking might not even make sense for btrfs but I thought I''d just ask. Thanks, Stephane -- To unsubscribe from this

Hi, I''m getting an error when trying to delete a device from a raid1 (data and metadata mirrored). > btrfs filesystem show failed to read /dev/sr0 Label: none uuid: 78b5162b-489e-4de1-a989-a47b91adef50 Total devices 2 FS bytes used 107.64GB devid 2 size 149.05GB used 109.01GB path /dev/sdh1 devid 1 size 156.81GB used 109.03GB path /dev/sdb6 Btrfs v0.20-rc1 >

Hi, I recently upgraded one of my fileservers from 2.4.16 to 2.4.18 plus the ext3-cvs.patch that Andrew Morton pointed me to for addressing and assertion failure. Since then I have been getting lots of errors like: May 21 14:07:03 glass kernel: EXT3-fs error (device md(9,0)): ext3_add_entry: bad entry in directory #2945366: rec_len %% 4 != 0 - offset=0, inode=1886221359, rec_len=24927,

Hi all, We are building a new system which is going to use ext3 FS. We would like to know more about the behavior of ext3 in the case of failure. But before I procede, I would like to share more information about our future system. * Our application always does an fsync on files * When symbolic links (more specifically fast symlink) are created, the host directory is also fsync'ed. * Our

If you export two subvolumes of a btrfs filesystem, they will both be given the same uuid so lookups will be confused. blkid cannot differentiate the two, so we must use the fsid from statfs64 to identify the filesystem. We cannot tell if blkid or statfs is best without knowing internal details of the filesystem in question, so we need to encode specific knowledge of btrfs in mountd. This is

Hi - I'm searching for file system corruption tool, say it inject disk-errors like multiply owned blocks etc. Later an integrity scan process (like e2fsck) will verify on-disk layout and fix these errors. I'd like to read/understand such tools before writing one for an proprietary on-disk file system. Do we have such tools for ext{2,3,4}fs ? Thanks for any help or pointers! -- ----

It is well documented that btrfs data recovery (after silent corruption) is dependent on the use of btrfs''s own RAID1. However, I''m curious about whether any hardware RAID vendors are contemplating ways to integrate more closely with btrfs, for example, such that when btrfs detects a bad checksum, it would be able to ask the hardware RAID controller to return all alternate

Hi all, we got a new test system here and I just also tested btrfs raid6 on that. Write performance is slightly lower than hw-raid (LSI megasas) and md-raid6, but it probably would be much better than any of these two, if it wouldn''t read all the during the writes. Is this a known issue? This is with linux-3.9.2. Thanks, Bernd -- To unsubscribe from this list: send the line

Hi all, Sorry for the OT. I've got an IBM N3300-A10 NAS. It runs Data Ontap 7.2.5.1. The problem is, from the docs it says that it only supports either RAID-DP or RAID4. What I want to achieve is Max Storage Capacity, so I change it from RAID-DP to RAID4, but with RAID4, the maximum disk in a RAID Group decrease from 14 to 7. In the end, either using RAID-DP or RAID4, the capacity is the same.

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 Hi all, this is a new attempt to improve the output of the command "btrfs fi df". The previous attempt received a good reception. However there was no a general consensus about the wording. Moreover I still didn''t understand how btrfs was using the disks. A my first attempt was to develop a new command which shows how the disks