similar to: Understanding Default RAID Behavior

Did something break.. ? we are not reporting raid type after balance. ----------- # btrfs fi df /btrfs Data, RAID0: total=2.00GB, used=2.03MB Data: total=8.00MB, used=0.00 System, RAID0: total=16.00MB, used=4.00KB System: total=4.00MB, used=0.00 Metadata, RAID0: total=2.00GB, used=216.00KB Metadata: total=8.00MB, used=4.00KB # btrfs bal /btrfs Done, had to relocate 5 out of 5 chunks # btrfs fi

-----BEGIN PGP SIGNED MESSAGE----- Hash: SHA1 I''ve been unable to find anything definitive about what happens if I use RAID0 to join an SSD and HDD together with respect to performance (latency, throughput). The future is obvious (hot data tracking, using most appropriate device for the data, data migration). In my specific case I have a 250GB SSD and a 500GB HDD, and about 250GB of

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

tl;dr version: 3.0 produces “bio too big” dmesg entries and silently corrupts data in “meta-raid1/data-single” configurations on disks with different max_hw_sectors, where 2.6.38 worked fine. tl;dr side-issue: on-line removal of partitions holding “single” data attempts to create raid0 (rather than single) block groups. If it can''t get enough room for raid0 over all remaining disks, it

If there is no free space, the free space allocator will try to get space from the block group with the degenerated profile. For example, if there is no free space in the RAID1 block groups, the allocator will try to allocate space from the DUP block groups. And besides that, the space reservation has the similar behaviour: if there is no enough space in the space cache to reserve, it will reserve

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

On Fri 07 January 2011 08:14:17 Hubert Kario wrote: > I''d suggest at least > mkfs.btrfs -m raid1 -d raid0 /dev/sdc /dev/sdd > if you really want raid0 I don''t fully understand -m or -d. Why would this make a truer raid0 that with no options? Is it necessary to use fdisk on new drives in creating a BTRFS multi-drive array? Or is this all that''s needed: #

For using SSDs: Are there any format/mount parameters that should be set for using btrfs on SSDs (other than the "ssd" mount option)? General questions: How long is the ''delay'' for the delayed alloc? Are file allocations aligned to 4kiB boundaries, or larger? What byte value is used to pad unused space? (Aside: For some, the erased state reads all 0x00, and for

Hi, I''m starting to play with btrfs on my new computer. I''m running Gentoo and have compiled the 2.6.31 kernel, enabling btrfs. Now I have 2 partitions (on 2 different sata disks) that are free for me to play with, each about 375 gb in size. I wanted to create a "raid1" volume using these two partitions, so I did: # mkfs.btrfs -d raid1 /dev/sda5 /dev/sdb5 # mount

Hi folks, For people who might be interested, here is how btrfs performs with two partitions on a single SSD drive in a RAID-1 mirror. This is on a Dell E4200 with Core 2 Duo U9300 (1.2GHz), 2GB RAM and a Samsung SSD (128GB Thin uSATA SSD). Version 1.03c ------Sequential Output------ --Sequential Input- --Random- -Per Chr- --Block-- -Rewrite- -Per Chr- --Block--

My computer running CentOS 7 is configured to use BIOS RAID0 and has two identical SSDs which are also encrypted. I had a crash the other day and due to a bug in the operating system update, I am unable to boot the system in RAID mode since dracut does not recognize the disks in grub. After modifying the grub command line I am able to boot the system from one of the harddisks after entering the

I'm trying to work out the kinks of a proprietary, old, and clunky application that runs on CentOS. One of its main problems is that it writes image sequences extremely non-linearly and in several passes, using many CPUs, so the sequences get very fragmented. The obvious solution to this seems to be to use SSDs for its output, and some scripts that will pick up and copy our the sequences

Hi Dongyang, Yan, When testing BTRFS with RAID 0 metadata on linux-3.3, we see discard ranges exceeding the end of the block device [1], potentially causing dataloss; when this occurs, filesystem writeback becomes catatonic due to continual resubmission. The reproducer is quite simple [2]. Hope this proves useful... Thanks, Daniel --- [1] attempt to access beyond end of device ram0: rw=129,

Here is a short proposal for the hybrid storage cache idea with introduction/motivation and a bird''s eye view of an approach to implement a hybrid storage cache for btrfs. Please note that there is currently no available patches. We would like to get as much input before as possible before we start designing and implementing a solution. 1. Introduction The emerge of Solid State

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 All, I''m new on the list. System: Distributor ID: Ubuntu Description: Ubuntu 13.04 Release: 13.04 Codename: raring Linux ctu 3.8.0-19-generic #30-Ubuntu SMP Wed May 1 16:35:23 UTC 2013 x86_64 x86_64 x86_64 GNU/Linux The symptom is the same with Saucy 3.9 kernel. ii btrfs-tools 0.20~git20130524~650e656-0daily13~raring1 amd64 Checksumming Copy on

While untar''ing an image to an sd card via a reader, I got the following bug. The system also has a btrfs root, and a whole swath of processes went into uninterruptable sleep. I was able to poke around via ssh and sysrq, and already had netconsole set up to capture the bug. Root fs is on /dev/sdi1, and /dev/sdj2 is the card reader which was the target of the untar. [29571.448889] sd

How can I verify the read speed of a btrfs raid0 pair in archlinux.? I assume raid0 means striped activity in a paralleled mode at lease similar to raid0 in mdadm. How can I measure the btrfs read speed since it is copy-on-write which is not the norm in mdadm raid0.? Perhaps I cannot use the same approach in btrfs to determine the performance. Secondly, I see a methodology for raid10 using

Hallo, "never change a running system" ... For some months I run btrfs unter kernel 3.2.5 and 3.2.9, without problems. Yesterday I compiled kernel 3.3.4, and this morning I started the machine with this kernel. There may be some ugly problems. Copying something into the btrfs "directory" worked well for some files, and then I got error messages (I''ve not

On 11/04/2020 10:21 PM, John Pierce wrote: > is it RAID 0 (striped) or raid1 (mirrored) ?? > > if you wrote on half of a raid0 stripe set, you basically trashed it. > blocks are striped across both drives, so like 16k on the first disk, then > 16k on the 2nd then 16k back on the first, repeat (replace 16k with > whatever your raid stripe size is). > > if its a raid 1