Re[2]: mdadm 2.6.4 : How i can check out current status of reshaping ?

2008-02-05 Thread Andreas-Sokov
Hello, Neil. YOU WROTE : 5 февраля 2008 г., 01:48:33: On Monday February 4, [EMAIL PROTECTED] wrote: [EMAIL PROTECTED]:/# cat /proc/mdstat Personalities : [linear] [raid0] [raid1] [raid10] [raid6] [raid5] [raid4] [multipath] [faulty] md1 : active raid5 sdc[0] sdb[5](S) sdf[3] sde[2]

Re: Re[2]: mdadm 2.6.4 : How i can check out current status of reshaping ?

2008-02-05 Thread Neil Brown
On Tuesday February 5, [EMAIL PROTECTED] wrote: Feb 5 11:56:12 raid01 kernel: BUG: unable to handle kernel paging request at virtual address 001cd901 This looks like some sort of memory corruption. Feb 5 11:56:12 raid01 kernel: EIP is at md_do_sync+0x629/0xa32 This tells us what code is

Deleting mdadm RAID arrays

2008-02-05 Thread Marcin Krol
Hello everyone, I have had a problem with RAID array (udev messed up disk names, I've had RAID on disks only, without raid partitions) on Debian Etch server with 6 disks and so I decided to rearrange this. Deleted the disks from (2 RAID-5) arrays, deleted the md* devices from /dev, created

Re: Deleting mdadm RAID arrays

2008-02-05 Thread Moshe Yudkowsky
1. Where this info on array resides?! I have deleted /etc/mdadm/mdadm.conf and /dev/md devices and yet it comes seemingly out of nowhere. /boot has a copy of mdadm.conf so that / and other drives can be started and then mounted. update-initramfs will update /boot's copy of mdadm.conf. --

Re: Deleting mdadm RAID arrays

2008-02-05 Thread Janek Kozicki
Marcin Krol said: (by the date of Tue, 5 Feb 2008 11:42:19 +0100) 2. How can I delete that damn array so it doesn't hang my server up in a loop? dd if=/dev/zero of=/dev/sdb1 bs=1M count=10 I'm not using mdadm.conf at all. Everything is stored in the superblock of the device. So if you

Re: RAID needs more to survive a power hit, different /boot layout for example (was Re: draft howto on making raids for surviving a disk crash)

2008-02-05 Thread Linda Walsh
Michael Tokarev wrote: note that with some workloads, write caching in the drive actually makes write speed worse, not better - namely, in case of massive writes. With write barriers enabled, I did a quick test of a large copy from one backup filesystem to another. I'm

Re: Deleting mdadm RAID arrays

2008-02-05 Thread Michael Tokarev
Janek Kozicki wrote: Marcin Krol said: (by the date of Tue, 5 Feb 2008 11:42:19 +0100) 2. How can I delete that damn array so it doesn't hang my server up in a loop? dd if=/dev/zero of=/dev/sdb1 bs=1M count=10 This works provided the superblocks are at the beginning of the component

Re: Auto generation of mdadm.conf (was: Deleting mdadm RAID arrays)

2008-02-05 Thread Janek Kozicki
Michael Tokarev said: (by the date of Tue, 05 Feb 2008 16:52:18 +0300) Janek Kozicki wrote: I'm not using mdadm.conf at all. That's wrong, as you need at least something to identify the array components. I was afraid of that ;-) So, is that a correct way to automatically generate a

Re: Deleting mdadm RAID arrays

2008-02-05 Thread Michael Tokarev
Moshe Yudkowsky wrote: Michael Tokarev wrote: Janek Kozicki wrote: Marcin Krol said: (by the date of Tue, 5 Feb 2008 11:42:19 +0100) 2. How can I delete that damn array so it doesn't hang my server up in a loop? dd if=/dev/zero of=/dev/sdb1 bs=1M count=10 This works provided the

Re: Deleting mdadm RAID arrays

2008-02-05 Thread Moshe Yudkowsky
Michael Tokarev wrote: Janek Kozicki wrote: Marcin Krol said: (by the date of Tue, 5 Feb 2008 11:42:19 +0100) 2. How can I delete that damn array so it doesn't hang my server up in a loop? dd if=/dev/zero of=/dev/sdb1 bs=1M count=10 This works provided the superblocks are at the

Re: Auto generation of mdadm.conf

2008-02-05 Thread Michael Tokarev
Janek Kozicki wrote: Michael Tokarev said: (by the date of Tue, 05 Feb 2008 16:52:18 +0300) Janek Kozicki wrote: I'm not using mdadm.conf at all. That's wrong, as you need at least something to identify the array components. I was afraid of that ;-) So, is that a correct way to

Re: which raid level gives maximum overall speed? (raid-10,f2 vs. raid-0)

2008-02-05 Thread Keld Jørn Simonsen
On Thu, Jan 31, 2008 at 02:55:07AM +0100, Keld Jørn Simonsen wrote: On Wed, Jan 30, 2008 at 11:36:39PM +0100, Janek Kozicki wrote: Keld Jørn Simonsen said: (by the date of Wed, 30 Jan 2008 23:00:07 +0100) All the raid10's will have double time for writing, and raid5 and raid6 will

Re: which raid level gives maximum overall speed? (raid-10,f2 vs. raid-0)

2008-02-05 Thread Justin Piszcz
On Tue, 5 Feb 2008, Keld Jørn Simonsen wrote: On Thu, Jan 31, 2008 at 02:55:07AM +0100, Keld Jørn Simonsen wrote: On Wed, Jan 30, 2008 at 11:36:39PM +0100, Janek Kozicki wrote: Keld Jørn Simonsen said: (by the date of Wed, 30 Jan 2008 23:00:07 +0100) All the raid10's will have double

recommendations for stripe/chunk size

2008-02-05 Thread Keld Jørn Simonsen
Hi I am looking at revising our howto. I see a number of places where a chunk size of 32 kiB is recommended, and even recommendations on maybe using sizes of 4 kiB. My own take on that is that this really hurts performance. Normal disks have a rotation speed of between 5400 (laptop) 7200

Re: Auto generation of mdadm.conf

2008-02-05 Thread Janek Kozicki
Michael Tokarev said: (by the date of Tue, 05 Feb 2008 18:34:47 +0300) ... So.. probably this is the way your arrays are being assembled, since you do have HOMEHOST in your mdadm.conf... Looks like it should work, after all... ;) And in this case there's no need to specify additional

Re: recommendations for stripe/chunk size

2008-02-05 Thread Justin Piszcz
On Tue, 5 Feb 2008, Keld Jørn Simonsen wrote: Hi I am looking at revising our howto. I see a number of places where a chunk size of 32 kiB is recommended, and even recommendations on maybe using sizes of 4 kiB. My own take on that is that this really hurts performance. Normal disks have a

Re: which raid level gives maximum overall speed? (raid-10,f2 vs. raid-0)

2008-02-05 Thread Keld Jørn Simonsen
On Tue, Feb 05, 2008 at 11:54:27AM -0500, Justin Piszcz wrote: On Tue, 5 Feb 2008, Keld Jørn Simonsen wrote: On Thu, Jan 31, 2008 at 02:55:07AM +0100, Keld Jørn Simonsen wrote: On Wed, Jan 30, 2008 at 11:36:39PM +0100, Janek Kozicki wrote: Keld Jørn Simonsen said: (by the date of

Re: Deleting mdadm RAID arrays

2008-02-05 Thread Neil Brown
On Tuesday February 5, [EMAIL PROTECTED] wrote: % mdadm --zero-superblock /dev/sdb1 mdadm: Couldn't open /dev/sdb1 for write - not zeroing That's weird. Why can't it open it? Maybe you aren't running as root (The '%' prompt is suspicious). Maybe the kernel has been told to forget about the

Re: which raid level gives maximum overall speed? (raid-10,f2 vs. raid-0)

2008-02-05 Thread Justin Piszcz
On Tue, 5 Feb 2008, Keld Jørn Simonsen wrote: On Tue, Feb 05, 2008 at 11:54:27AM -0500, Justin Piszcz wrote: On Tue, 5 Feb 2008, Keld Jørn Simonsen wrote: On Thu, Jan 31, 2008 at 02:55:07AM +0100, Keld Jørn Simonsen wrote: On Wed, Jan 30, 2008 at 11:36:39PM +0100, Janek Kozicki wrote:

Re: which raid level gives maximum overall speed? (raid-10,f2 vs. raid-0)

2008-02-05 Thread Janek Kozicki
Justin Piszcz said: (by the date of Tue, 5 Feb 2008 17:28:27 -0500 (EST)) I remember testing with bonnie++ and raid10 was about half the speed (200-265 MiB/s) as RAID5 (400-420 MiB/s) for sequential output, writing on raid10 is supposed to be half the speed of reading. That's because it

Re: which raid level gives maximum overall speed? (raid-10,f2 vs. raid-0)

2008-02-05 Thread Keld Jørn Simonsen
On Tue, Feb 05, 2008 at 05:28:27PM -0500, Justin Piszcz wrote: Could you give some figures? I remember testing with bonnie++ and raid10 was about half the speed (200-265 MiB/s) as RAID5 (400-420 MiB/s) for sequential output, but input was closer to RAID5 speeds/did not seem affected

Re: which raid level gives maximum overall speed? (raid-10,f2 vs. raid-0)

2008-02-05 Thread Justin Piszcz
On Tue, 5 Feb 2008, Keld Jørn Simonsen wrote: On Tue, Feb 05, 2008 at 05:28:27PM -0500, Justin Piszcz wrote: Could you give some figures? I remember testing with bonnie++ and raid10 was about half the speed (200-265 MiB/s) as RAID5 (400-420 MiB/s) for sequential output, but input was

Re: RAID needs more to survive a power hit, different /boot layout for example (was Re: draft howto on making raids for surviving a disk crash)

2008-02-05 Thread Linda Walsh
Michael Tokarev wrote: Unfortunately an UPS does not *really* help here. Because unless it has control program which properly shuts system down on the loss of input power, and the battery really has the capacity to power the system while it's shutting down (anyone tested this?

Re: RAID needs more to survive a power hit, different /boot layout for example (was Re: draft howto on making raids for surviving a disk crash)

2008-02-05 Thread Michael Tokarev
Linda Walsh wrote: Michael Tokarev wrote: Unfortunately an UPS does not *really* help here. Because unless it has control program which properly shuts system down on the loss of input power, and the battery really has the capacity to power the system while it's shutting down (anyone tested