similar to: RAID5/6 Implementation - Understanding first

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

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

I can't seem to get the read and write performance better than approximately 40MB/s on an ext2 file system. IMO, this is horrible performance for a 6-drive, hardware RAID 5 array. Please have a look at what I'm doing and let me know if anybody has any suggestions on how to improve the performance... System specs: ----------------- 2 x 2.8GHz Xeons 6GB RAM 1 3ware 9500S-12 2 x 6-drive,

I'm setting up a new fileserver. It has two RAID controllers, a PERC 3/DI providing mirrored system disks and a PERC 3/DC providing a 1TB RAID5 volume consisting of eight 144GB U160 drives. This will serve NFS, Samba and sftp clients for about 200 users. The logical drive was created with the following settings: RAID = 5 stripe size = 32kb write policy = wrback read policy =

This series introduces a generic readahead interface for btrfs trees. The intention is to use it to speed up scrub in a first run, but balance is another hot candidate. In general, every tree walk could be accompanied by a readahead. Deletion of large files comes to mind, where the fetching of the csums takes most of the time. Also the initial build-ups of free-space-caches and

Hi list, as this matter pops up every now and then in posts on this list I just want to clarify that the real performance of RaidZ (in its current implementation) is NOT anything that follows from raidz-style data efficient redundancy or the copy-on-write design used in ZFS. In a M-Way mirrored setup of N disks you get the write performance of the worst disk and a read performance that is

I run a decent amount of 3ware hardware, all under centos-4. There seems to be some sort of fundamental disagreement between ext3 and 3ware's hardware RAID5 mode that trashes write performance. As a representative example, one current setup is 2 9550SX-12 boards in hardware RAID5 mode (256KB stripe size) with a software RAID0 stripe on top (also 256KB chunks). bonnie++ results look

I am trying to use a WaitExten in a Macro, and I am finding that the extension which is pressed ends up in context of the calling context and not in the Macro. How do you do a WaitExten in a Macro? Tony Plack

If we''ve abandoned the idea of putting the number of redundant blocks into the top bits of the type bitmask (and I hope we have), then we''re fairly much there. Current code is at: git://, http://git.infradead.org/users/dwmw2/btrfs-raid56.git git://, http://git.infradead.org/users/dwmw2/btrfs-progs-raid56.git We have recovery working, as well as both full-stripe writes

On Jun 2, 2017, at 5:05 AM, hw <hw at gc-24.de> wrote: > > Warren Young wrote: >> >> There are various options. We use mod_fcgid + Plack here. > I need to look into that when I have time. I wonder if it wouldn?t have been faster to just backport the app to Perl 5.16? How hard could it be? It?s not like Perl 5.16 is a hopelessly lame and incapable language. The

greetings, i just know i have read several times on this list and in other places that on a RAID5 array that the MBR should be placed on the /boot partition. is this truly correct and if so, why? my experiences of putting the MBR on the /boot partition are contrary to that it will even work and boot that way... comments please? regards, - rh -- Robert Hanson Abba Communications

Hello all, I have yesterday after some typos, sent my ext3 RAID5 array to the void... I want to recreate it now, but I read on http://wiki.centos.org/HowTos/Disk_Optimization that you can optimize the filesystem on top of the RAID. Will this wiki article be exactly the same for XFS? Is it worth the trouble to also create an LVM volume on the RAID array? Regards, Coert

I am working on a project that requires shared extension. Where shared line looks at the status of a line/trunk, shared extension would look at a series of channels as the same "extension". The users would like to add destination channels on the fly, to provide roaming extensions, but maintaining fixed channels as well. If a call comes in on an extension, the system needs to honor the

This series introduces a generic readahead interface for btrfs trees. The intention is to use it to speed up scrub in a first run, but balance is another hot candidate. In general, every tree walk could be accompanied by a readahead. Deletion of large files comes to mind, where the fetching of the csums takes most of the time. Also the initial build-ups of free-space-caches and

On May 24, 2017, at 9:38 AM, hw <hw at gc-24.de> wrote: > > Warren Young schrieb: >> On May 24, 2017, at 7:05 AM, hw <hw at gc-24.de> wrote: >>> apache uses mod_perl >> >> mod_perl was dropped from Apache in 2.4, and Red Hat followed suit with RHEL 7. > > What is it using instead? There are various options. We use mod_fcgid + Plack here. And

In a multi device setup, the chunk allocator currently always allocates chunks on the devices in the same order. This leads to a very uneven distribution, especially with RAID1 or RAID10 and an uneven number of devices. This patch always sorts the devices before allocating, and allocates the stripes on the devices with the most available space, as long as there is enough space available. In a low

Apologies for the blank message (if it came through). I have heard here and there that there might be in development a plan to make it such that a raid-z can grow its "raid-z''ness" to accommodate a new disk added to it. Example: I have 4Disks in a raid-z[12] configuration. I am uncomfortably low on space, and would like to add a 5th disk. The idea is to pop in disk 5 and have

On May 24, 2017, at 7:05 AM, hw <hw at gc-24.de> wrote: > apache uses mod_perl mod_perl was dropped from Apache in 2.4, and Red Hat followed suit with RHEL 7. > But there is a package 'rh-perl524-mod_perl?. That must be someone?s backport. As someone who migrated a mod_perl based app off of mod_perl several years ago, I recommend that you do not use it, unless you have old

In a multi device setup, the chunk allocator currently always allocates chunks on the devices in the same order. This leads to a very uneven distribution, especially with RAID1 or RAID10 and an uneven number of devices. This patch always sorts the devices before allocating, and allocates the stripes on the devices with the most available space, as long as there is enough space available. In a low

The biggest one is a fix for fstrim, and there''s a fix for on-disk free space cache. Others are small fixes and cleanups. The last three have been sent weeks ago. The patchset is also available in this repo: git://repo.or.cz/linux-btrfs-devel.git for-chris Note there''s a small confict with Al Viro''s vfs changes. Li Zefan (11): Btrfs: add pinned extents to