search for: raid0

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 performan...

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 on...

...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 in proper order once it's done. I have two 512GB SSDs, and I've used LVM to set up a RAID0 between them. I've got that part running, but since I'm on CentOS 5.8 (which is what this application officially supports), I don't have a kernel with SSD discard support, and after a few days (I told you, this application is write intensive), things get very slow. Using hdparm to...

Hey! I have big problem with my centos 5.1. I have two hard discs 500gig and 40gig and those are in RAID0. I would like to remowe the small 40gig hd and put new 500gig hd and i don't wan't raid0 anymore. How can i copy data from 40gig hd to 500gig hd and switch 40gig hd to new 500gig hd? Another question: Can i just copy all my files to windows laptop and if i wan't "backup" f...

Hello, I had a scientific linux 3.0.4 system (rhel compatible), with 3 ide disks, one for / and two others in linear raid (250 gb and 300 gb each). This system was obsoleted so i move the raid disks to a new scientific linux 3.0.7 installation. However, the raid array was not detected ( I put the disks on the same channels and same master/lsave setup as in the previous setup). In fact

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 mirror, then either disk by itself has th...

> On Nov 4, 2020, at 9:21 PM, John Pierce <jhn.pierce at gmail.com> 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 mirror, then either disk by itself has t...

hi guys, gals do you know if conversion from lvm's raid10 to raid0 is possible? I'm fiddling with --splitmirrors but it gets me nowhere. On "takeover" subject man pages says: "..between striped/raid0 and raid10."" but no details, nowhere I could find documentation, nor a howto. many thanks, L.

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 mirror, then either disk by itself has the complete file system o...

The Wiki does not make it clear as to why adding a secondary device defaults to RAID1 metadata and RAID0 data. I bought two SSDs with the intention of doing a BTRFS RAID0 for my root. What is the difference between forcing RAID0 on metadata and data as opposed to the default behavior? Can anyone clarify that? Thank you for your time, Mario -- To unsubscribe from this list: send the line "unsu...

On Mon, Feb 16, 2015 at 6:47 AM, Eliezer Croitoru <eliezer at ngtech.co.il> wrote: > I am unsure I understand what you wrote. > "XFS will create multiple AG's across all of those > devices," > Are you comparing md linear/concat to md raid0? and that the upper level XFS > will run on top them? Yes to the first question, I'm not understanding the second question. Allocation groups are created at mkfs time. When the workload IO involves a lot of concurrency, XFS over linear will beat XFS or ext4 over raid0. Whereas for streaming...

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 df /btrfs Data:...

I noticed that if I have single-device allocation for data in a multi-device btrfs filesystem, a balance operation will convert the data to RAID0. This is true even if ''-d single'' is specified explicitly when creating the filesystem. Then it wants to continue using RAID0 for future data allocations, and I run out of space once there''s no longer two drives with space available. I hit this problem when adding to...

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 fails, leaving the available space incorrect (even underflowed). If it succeeds, it creates raid0 block groups and permanently (?) switches the FS to raid0. I''ve been (more or...

..., 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 the space according to the disk space, and it just take mirror storage into account, no RAID0, RAID1, or RAID10. So we''d better make the behaviour of chunk allocation correspond with space reservation and free space allocation, if there is no enough disk space to allocate RAID(RAID0, RAID1, RAID10) chunks, we degenerate the profile and try to allocate chunks again. Otherwise, enos...

...wrote: > On Mon, Feb 16, 2015 at 6:47 AM, Eliezer Croitoru <eliezer at ngtech.co.il> wrote: > >> I am unsure I understand what you wrote. >> "XFS will create multiple AG's across all of those >> devices," >> Are you comparing md linear/concat to md raid0? and that the upper level XFS >> will run on top them? > > Yes to the first question, I'm not understanding the second question. > Allocation groups are created at mkfs time. When the workload IO > involves a lot of concurrency, XFS over linear will beat XFS or ext4 > over...

Hi, So the case is, now I''ve got a btrfs image file, which is created from a raid0 btrfs fs. And if I run ''btrfs-image -r image_file /dev/sdf'', then I have to mount it with ''degraded'' mode, and that still fails because raid0 requires two disks at least. So any ideas how to make it work? thanks, liubo -- To unsubscribe from this list: send th...

Hi folks: At work, I have an R510, and R610 and an R710 - all with the H700 PERC controller. Based on experiments, it seems like there is no way to bypass the PERC controller - it seems like one can only access the individual disks if they are set up in RAID0 each. This brings me to ask some questions: a. Is it fine (in terms of an intelligent controller coming in the way of ZFS) to have the PERC controllers present each drive as RAID0 drives ? b. Would there be any errors in terms of PERC doing things that ZFS is not aware of and this causing any issu...

Hi, I do have a disk array that is providing striped LUNs to my Solaris box. Hence I''d like to simply concat those LUNs without adding another layer of striping. Is this possibile with ZFS? As far as I understood, if I use zpool create myPool lun-1 lun-2 ... lun-n I will get a RAID0 striping where each data block is split across all "n" LUNs. If that''s correct, is there a way to avoid that and get ZFS to write sequentially on the LUNs that are part of myPool? Thanks, Piero -- This message posted from opensolaris.org

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...