raidreconf aborted after being almost done
I tried to add a 6th disk to a RAID-5 with raidreconf 0.1.2 Almost being done raidreconf aborted with the error message: raid5_map_global_to_local: disk 0 block out of range: 2442004 (2442004) gblock = 7326012 aborted After searching the web I believe this is due to different disk sizes. Because I use different disks (vendor and type) having different geometries it is not possible to have partitions of exact the same size. They match as good as possible but some always have different amounts of blocks. It would be great if raidreconf would complain about the different disk sizes and abort prior to messing up the disks. Is there any way I can recover my RAID device? I tried raidstart on it but it started using only the old setup with 5 disks without including the new one. How do I start the array including the 6th disk? Regards Klaus - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Problem with auto-assembly on Itanium
On Wed, 2005-03-09 at 17:43 +0100, Luca Berra wrote: > On Wed, Mar 09, 2005 at 11:28:48AM +0100, Jimmy Hedman wrote: > >Is there any way i can make this work? Could it be doable with mdadm in > >a initrd? > > > mdassembled was devise for this purpose. > > create an /etc/mdadm.conf with > echo "DEVICE partitions" >> /etc/mdadm.conf > /sbin/mdadm -D -b /dev/md0 | grep '^ARRAY' >> /etc/mdadm.conf > > copy the mdadm.conf and mdassemble to initrd > make linuxrc run mdassemble. So there are no way of doing it the same way i386 does it, ie scanning the partitions and assembly the raid by it self? Is this a bug on the itanium (GPT partition scheme) or is this intentional? // Jimmy > L. > - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: raidreconf aborted after being almost done
[EMAIL PROTECTED] wrote: After searching the web I believe this is due to different disk sizes. Because I use different disks (vendor and type) having different geometries it is not possible to have partitions of exact the same size. They match as good as possible but some always have different amounts of blocks. AFAIK the size of a block differs between disks with an unequal number of heads. I had this problem with some identical drives. (some with 16 heads and some with 255) It is possible to set these parameters with fdisk and have drives with equal geometry or (in case of different models) with comparible geometry which allows to have partitions of exactly the same size. fdisk --help doesn't mention this possibility but ists manpage does: Run fdisk with fdisk -b -C -H -S device and alter the partition table. Then exit with writing. After that your disk has a new geometry. Greetings, Frank signature.asc Description: OpenPGP digital signature
Re: md Grow for Raid 5
Neil Brown wrote: Growing a raid5 or raid6 by adding another drive is conceptually possible to do while the array is online, but I have not definite plans to do this (I would like to). Growing a raid5 into a raid6 would also be useful. These require moving lots of data around, and need to be able to cope with drive failure and system crash a fun project.. EVMS has this already. It works and is supported (whereas I didn't think raidreconf was). It would be nice to move the EVMS raid5 extension code into the core md. FYI, I used EVMS briefly and found it to be an excellent toolset. It's a teeny bit rough and a bit OTT for a personal server though so I'm sticking with md/lvm2 for now :) David - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
shuffled disks by mistake
Hi, I have 6 WD800Jb disk drives. I used 4 of them in a RAID5 (using the whole disk - no partitions) array. I have mixed them all up, and now want to get some data off the array. How best to find out which drives were in the array? Here are the partition tables (obtained using fdisk on OS X): WCAHL6712963.txt Disk: /dev/rdisk2 geometry: 9729/255/63 [156301488 sectors] Signature: 0x0 Starting Ending #: id cyl hd sec - cyl hd sec [ start - size] 1: 000 0 0 -0 0 0 [ 0 - 0] unused 2: 000 0 0 -0 0 0 [ 0 - 0] unused 3: 000 0 0 -0 0 0 [ 0 - 0] unused 4: 000 0 0 -0 0 0 [ 0 - 0] unused WCAHL6713265.txt Disk: /dev/rdisk2 geometry: 9729/255/63 [156301488 sectors] Signature: 0x6972 Starting Ending #: id cyl hd sec - cyl hd sec [ start - size] 1: 000 0 0 -0 0 0 [ 0 - 0] unused 2: 69 1023 53 45 - -108478 -118 -1 [1210083443 - 1342177348] Novell 3: 000 0 0 -0 0 0 [ 0 - 0] unused 4: 000 0 0 -0 0 0 [ 0 - 0] unused WCAHL6727415.txt Disk: /dev/rdisk2 geometry: 9729/255/63 [156301488 sectors] Signature: 0x0 Starting Ending #: id cyl hd sec - cyl hd sec [ start - size] 1: 000 0 0 -0 0 0 [ 0 - 0] unused 2: 000 0 0 -0 0 0 [ 0 - 0] unused 3: 000 0 0 -0 0 0 [ 0 - 0] unused 4: 000 0 0 -0 0 0 [ 0 - 0] unused WCAHL6731043.txt Disk: /dev/rdisk2 geometry: 9729/255/63 [156301488 sectors] Signature: 0x6972 Starting Ending #: id cyl hd sec - cyl hd sec [ start - size] 1: 000 0 0 -0 0 0 [ 0 - 0] unused 2: 69 1023 53 45 - -108478 -118 -1 [1210083443 - 1342177348] Novell 3: 000 0 0 -0 0 0 [ 0 - 0] unused 4: 000 0 0 -0 0 0 [ 0 - 0] unused WCAJ93156707.txt Disk: /dev/rdisk2 geometry: 9729/255/63 [156301488 sectors] Signature: 0xAA55 Starting Ending #: id cyl hd sec - cyl hd sec [ start - size] *1: 830 1 1 - 12 254 63 [63 - 208782] Linux files* 2: 8E 13 0 1 - 1023 254 63 [208845 - 156087540] 3: 000 0 0 -0 0 0 [ 0 - 0] unused 4: 000 0 0 -0 0 0 [ 0 - 0] unused WMA8E2951092.txt Disk: /dev/rdisk2 geometry: 9729/255/63 [156301488 sectors] Signature: 0x0 Starting Ending #: id cyl hd sec - cyl hd sec [ start - size] 1: 000 0 0 -0 0 0 [ 0 - 0] unused 2: 000 0 0 -0 0 0 [ 0 - 0] unused 3: 000 0 0 -0 0 0 [ 0 - 0] unused 4: 000 0 0 -0 0 0 [ 0 - 0] unused Max. - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: shuffled disks by mistake
On Thu, 2005-03-10 at 22:17 +0800, Max Waterman wrote: > Hi, > > I have 6 WD800Jb disk drives. I used 4 of them in a RAID5 (using the > whole disk - no partitions) array. > > I have mixed them all up, and now want to get some data off the array. > > How best to find out which drives were in the array? > > Here are the partition tables (obtained using fdisk on OS X): put the drives in a linux machine and run: mdadm -E /dev/drive# it should tell you if there is an md superblock on that system. -sv - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: shuffled disks by mistake
Max Waterman wrote: I have 6 WD800Jb disk drives. I used 4 of them in a RAID5 (using the whole disk - no partitions) array. I have mixed them all up, and now want to get some data off the array. How best to find out which drives were in the array? put them in a linux box and run "mdadm -E " on each disk -- that will tell you which ones have superblocks and all the details of those superblocks -- Paul - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Problems with Linux RAID in kernel 2.6
Hi,
I have many problems with RAID in kernel 2.6.10.
First of all, I have the md, raid1,... into the kernel, superblocks in
the RAIDs and "Linux RAID autodetect" as the partition types. Moreover,
I make an initrd. However, when the kernel boots, it doesn't recognize
the RAID disks:
md: raid1 personality registered as nr 3
md: md driver 0.90.1 MAX_MD_DEVS=256, MD_SB_DISKS=27
[...]
md: Autodetecting RAID arrays.
md: autorun ...
md: ... autorun DONE.
And I have four RAID disks (/dev/md[1-4]) bind on /dev/sdb[1-4] and
/dev/sdc[1-4].
Secondly, I try to get up the RAID disks manually and the most times
it fails:
centralmad:~# cat /proc/mdstat
Personalities : [raid1]
unused devices:
centralmad:~#
centralmad:~# raidstart /dev/md2
/dev/md2: Invalid argument <-- Why did it say it?
centralmad:~# cat /proc/mdstat
Personalities : [raid1]
md2 : active raid1 sdc2[0] sdb2[1] <-- Although It seems to run Ok
14651200 blocks [2/2] [UU]
unused devices:
And dmesg says:
md: raidstart(pid 2944) used deprecated START_ARRAY ioctl. This will not
<-- !!!
be supported beyond 2.6
<-- !!!
md: could not bd_claim sda2.
<-- I have a «failured disk»
md: autostart failed!
<-- !!! Is it because the failured dik?
md: raidstart(pid 2944) used deprecated START_ARRAY ioctl. This will not
be supported beyond 2.6
md: autorun ...
md: considering sdc2 ...
md: adding sdc2 ...
md: adding sdb2 ...
md: created md2
md: bind
md: bind
md: running:
raid1: raid set md2 active with 2 out of 2 mirrors
md: ... autorun DONE.
Maybe raidstart need to change the ioctl to use. I have raidtools2
version 1.00.3-17 (Debian package in Sarge). A strace of that command
shows:
[...]
open("/dev/md2", O_RDWR)= 3
fstat64(3, {st_mode=S_IFBLK|0660, st_rdev=makedev(9, 2), ...}) = 0
ioctl(3, 0x800c0910, 0xbfffefb0)= 0
fstat64(3, {st_mode=S_IFBLK|0660, st_rdev=makedev(9, 2), ...}) = 0
ioctl(3, 0x800c0910, 0xb070)= 0
ioctl(3, 0x400c0930, 0xb100)= -1 EINVAL (Invalid argument)
write(2, "mdadm: failed to run array /dev/"..., 54mdadm: failed to run
array /dev/md2: Invalid argument
) = 54
close(3)= 0
exit_group(1) = ?
Raidstop seems not to have problems:
md: md2 stopped.
md: unbind
md: export_rdev(sdc2)
md: unbind
md: export_rdev(sdb2)
And with mdadm also fails:
centralmad:~# mdadm -R /dev/md2
mdadm: failed to run array /dev/md2: Invalid argument
centralmad:~# cat /proc/mdstat
Personalities : [raid1]
unused devices:
Moreover, dmesg says the md driver fails:
md: bug in file drivers/md/md.c, line 1514
md: **
md: * *
md: **
md2:
md0:
md: **
That line is in the function «static int do_md_run(mddev_t * mddev)»,
and the code that produce the bug is:
if (list_empty(&mddev->disks)) {
MD_BUG();
return -EINVAL;
}
Again, with «mdadm -S /dev/md2» there are no problems to stop the
RAID.
Here there are more information about my sistem. It is a Debian Sarge
with kernel 2.6, RAID 1 and SATA disks.
centralmad:~# mdadm -E /dev/sdb2
/dev/sdb2:
Magic : a92b4efc
Version : 00.90.00
UUID : 8c51d044:cb84e69a:64968ecd:2e36133c
Creation Time : Sun Mar 6 16:11:00 2005
Raid Level : raid1
Raid Devices : 2
Total Devices : 2
Preferred Minor : 2
Update Time : Mon Mar 7 17:59:30 2005
State : clean
Active Devices : 2
Working Devices : 2
Failed Devices : 0
Spare Devices : 0
Checksum : 1906699c - correct
Events : 0.1491
Number Major Minor RaidDevice State
this 1 8 181 active sync /dev/sdb2
0 0 8 340 active sync /dev/sdc2
1 1 8 181 active sync /dev/sdb2
Why do these problems occur? How can I/You solve them?
Thanks a lot. I will wait your response.
Regards,
--
--- Jesús Rojo Martínez. ---
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: now on to tuning....
Hmm.. for me:
> smartctl -A -d ata /dev/sda
On my work machine with Debian Sarge:
smartctl version 5.32 Copyright (C) 2002-4 Bruce Allen
Home page is http://smartmontools.sourceforge.net/
Smartctl: Device Read Identity Failed (not an ATA/ATAPI device)
A mandatory SMART command failed: exiting. To continue, add one or
more '-T permissive' options.
Did you apply the libata patch? I saw that here:
http://smartmontools.sourceforge.net/#testinghelp
I'm on kernel 2.6.10 and haven't applied any patches.. maybe it's
included on 2.6.11 now or a difference between smartctl 5.32 and 5.33?
The drives I have are on an Intel ICH5 SATA controller. I am doing a
few RAIDed partitions between a couple of 120GB drives since I
reinstalled my work machine a few weeks ago. I think I'm using libata
(the option marked as 'conflicting' with it isn't enabled in my
kernel). Any thoughts?
Derek
On Wed, 9 Mar 2005 11:53:11 +0100, [EMAIL PROTECTED]
<[EMAIL PROTECTED]> wrote:
> Good point about maxing out the pci bus... - I already use the nForce for
> mirrored boot drives, so that's not an option. The IDE controllers are empty
> at the moment (save for a DVD drive); I will give this a thought.
>
> Thanks for the feedback,
>
> -P
>
> -Original Message-
> From: [EMAIL PROTECTED]
> [mailto:[EMAIL PROTECTED] Behalf Of Nicola Fankhauser
> Sent: Wednesday, March 09, 2005 10:48 AM
> To: linux-raid@vger.kernel.org
> Subject: Re: now on to tuning
>
> hi peter
>
> [EMAIL PROTECTED] wrote:
> > I have been lurking for a while I recently put together a raid 5
> > system (Asus K8NE SIL 3114/2.6.8.1 kernel) with 4 300GB SATA Seagate
> > drives (a lot smaller than the bulk of what seems to be on this
> > list!). Currently this is used for video and mp3 storage, being
> > Reiser on LVM2.
>
> beware that LVM2 _can_ affect your performance. I too believed that the
> concept of dynamic drives is good, but I experienced a performance hit
> of about 50% (especially in sequential reads).
>
> see my blog entry describing how I built my 2TB file-server at
> http://variant.ch/phpwiki/WikiBlog/2005-02-27 for some numbers and more
> explanation.
>
> the K8NE has the same SiI 3114 controller as the board I used has; it is
> connected by a 33mhz 32bit PCI bus and maxes out at 133MiB/s, so for
> maxmimum performance you might want to connect only two drives to this
> controller, the other two to the nforce3 chipset SATA ports.
>
> > Bonnie++ to test, but with which parameters ?
>
> normally it's enough to specify a test-file larger (e.g. twice) the
> memory capacity of the machine you are testing. for a machine with 1GiB RAM:
>
> # bonnie++ -s 2gb {other options}
>
> you might as well want to specify the "fast" option which skips per-char
> operations (which are quite useless to test IMHO):
>
> # bonnie++ -f {other options}
>
> HTH
> nicola
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to [EMAIL PROTECTED]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
> -
> To unsubscribe from this list: send the line "unsubscribe linux-raid" in
> the body of a message to [EMAIL PROTECTED]
> More majordomo info at http://vger.kernel.org/majordomo-info.html
>
--
Derek Piper - [EMAIL PROTECTED]
http://doofer.org/
-
To unsubscribe from this list: send the line "unsubscribe linux-raid" in
the body of a message to [EMAIL PROTECTED]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Joys of spare disks!
Hmmm, yea.. I'm hoping I get a better one next time. I'll bore you to tears, I mean, let you know when it comes in :D Derek PS: Make sure the 'saveauto' is set to on for SMART data to be saved automatically through power-cycles i.e. > smartctl --saveauto=on /dev/hda you might want to do this too: > smartctl --offlineauto=on /dev/hda On Wed, 9 Mar 2005 12:04:41 -0500, Guy <[EMAIL PROTECTED]> wrote: > My drives reset the "power on time" when they power on. So I can't be sure > how long my drives have been on. But at least 6 of them have been in use > 24/7 for 2.5 years. I have powered them down on occasion. sdh was replaced > a few months ago. But the problem was with the power cable, not the drive. > But did not determine this until after I swapped the drives. On Jan 18 sdg > had only 19 entries. Anyway, 2 of them still have zero bad blocks. > > And for what it's worth, I have had many problems with re-built disks. > Once, out of 5 disks, 3 were bad, out of the box. I have learned that > repaired disks suck, even Seagate. > > Guy > > Status of my 2.5 year old disks: > /dev/sdd - 5 entries (40 bytes) in grown table. > /dev/sde - 0 entries (0 bytes) in grown table. > /dev/sdf - 12 entries (96 bytes) in grown table. > /dev/sdg - 21 entries (168 bytes) in grown table. > /dev/sdh - 0 entries (0 bytes) in grown table. > /dev/sdi - 6 entries (48 bytes) in grown table. > /dev/sdj - 0 entries (0 bytes) in grown table. > > -Original Message- > From: Derek Piper [mailto:[EMAIL PROTECTED] > Sent: Tuesday, March 08, 2005 12:15 PM > To: Guy > Subject: Re: Joys of spare disks! > > Heh.. I too have Seagate drives and have RMA'd even the drive they > sent back to replace the one I RMA'd a month or so ago. Normally > they're great, so I'm hoping the next replacement will fair better. > > The one they sent back had more than 1 unrecoverable sector errors > (!) according to smartctl by the time I RMA'd it (the first one, my > original drive, that I sent back had 3). It failed its self-tests and > all of Seagate's SeaTools tests too. The drive wasn't mishandled by > me, although I thought Seagate's own packaging looked a bit crap (two > pieces of black plastic suspending the drive within a plastic 'shell' > (the so called 'SeaShell' :>) within the box. No peanuts or bubble > wrap or anything else. Still, the drive worked at first and then > within 48hrs had problems. > > I have other Seagate drives that have been run for over 15000 without > a single even reallocated bad sector. I might have to try Peter's > patch though, since I am running them in RAID-1. > > Derek > > /trying to un-lurk on the list (i.e. read the 120 threads that have > appeared since I forgot about checking my gmail account) > > On Wed, 2 Mar 2005 00:53:51 -0500, Guy <[EMAIL PROTECTED]> wrote: > > That has not been my experience, but I have Seagate drives! > > > > Guy > > > > -Original Message- > > From: [EMAIL PROTECTED] > > [mailto:[EMAIL PROTECTED] On Behalf Of Brad Campbell > > Sent: Tuesday, March 01, 2005 11:57 PM > > To: Robin Bowes > > Cc: linux-raid@vger.kernel.org > > Subject: Re: Joys of spare disks! > > > > Robin Bowes wrote: > > > > > Thanks to some advice from Guy the "failed" disk is now back up and > > > running. > > > > > > To fix it I did the following; > > > > > > > > > Just watch that disk like a hawk. I had two disks fail recently in the > same > > way, I did exactly what > > you did and 2 days later they both started to grow defects again and got > > kicked out of the array. I > > RMA'd both of them last week as they would not stay stable for more than a > > day or two after > > re-allocation. > > > > Regards, > > Brad > > -- > > "Human beings, who are almost unique in having the ability > > to learn from the experience of others, are also remarkable > > for their apparent disinclination to do so." -- Douglas Adams > > - > > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > > the body of a message to [EMAIL PROTECTED] > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > - > > To unsubscribe from this list: send the line "unsubscribe linux-raid" in > > the body of a message to [EMAIL PROTECTED] > > More majordomo info at http://vger.kernel.org/majordomo-info.html > > > > -- > Derek Piper - [EMAIL PROTECTED] > http://doofer.org/ > > -- Derek Piper - [EMAIL PROTECTED] http://doofer.org/ - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Problem with auto-assembly on Itanium
On Thu, Mar 10, 2005 at 11:03:44AM +0100, Jimmy Hedman wrote: On Wed, 2005-03-09 at 17:43 +0100, Luca Berra wrote: On Wed, Mar 09, 2005 at 11:28:48AM +0100, Jimmy Hedman wrote: >Is there any way i can make this work? Could it be doable with mdadm in >a initrd? > mdassembled was devise for this purpose. create an /etc/mdadm.conf with echo "DEVICE partitions" >> /etc/mdadm.conf /sbin/mdadm -D -b /dev/md0 | grep '^ARRAY' >> /etc/mdadm.conf copy the mdadm.conf and mdassemble to initrd make linuxrc run mdassemble. So there are no way of doing it the same way i386 does it, ie scanning the partitions and assembly the raid by it self? Is this a bug on the itanium (GPT partition scheme) or is this intentional? if you mean the in-kernel autodetect junk, you should only be happy it does not work on your system, so you are not tempted to use it. even on i386 it is badly broken, and i won't return on the subject. it has been discussed on this list to boredom. L. btw. you don't need cc-ing me. i read the list. L. -- Luca Berra -- [EMAIL PROTECTED] Communication Media & Services S.r.l. /"\ \ / ASCII RIBBON CAMPAIGN XAGAINST HTML MAIL / \ - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Convert raid5 to raid1?
Was planning to adding a hot spare to my 3 disk raid5 array and was thinking if I go to 4 drives I would be a better off as 2 raid1 arrays considering the current state of raid5. If you think that is wrong please speak up now :) Thinking I would make a raid1 array for /. The rest of the first pair and the second pair of disks raid1 and tie together with lvm2. Can easily fit what I have so far on 1 drive so figure I could build the first 2 raids on it them copy from the current degraded array. Just wonder what happens to the md sequence when I remove the original raid arrays? When I'm done will I have md0,md1 and md2 or md2,md3 and md4? John - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Convert raid5 to raid1?
John McMonagle wrote: Just wonder what happens to the md sequence when I remove the original raid arrays? When I'm done will I have md0,md1 and md2 or md2,md3 and md4? they will have the name you entered when you created the array. after removing one array from the system all arrays will still have their original device-number after reboot. greetings, frank - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Convert raid5 to raid1?
John McMonagle wrote: Was planning to adding a hot spare to my 3 disk raid5 array and was thinking if I go to 4 drives I would be a better off as 2 raid1 arrays considering the current state of raid5. I just wonder about the comment "considering the current state of raid5". What might be wrong with raid5 currently? I certainly know a number of people (me included) who run several "large" raid-5 arrays and don't have any problems. Brad -- "Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so." -- Douglas Adams - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Convert raid5 to raid1?
The only problem I have is related to bad blocks. This problem is common to all RAID types. RAID5 is more likely to have problems. Guy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of Brad Campbell Sent: Thursday, March 10, 2005 6:04 PM To: John McMonagle Cc: linux-raid@vger.kernel.org Subject: Re: Convert raid5 to raid1? John McMonagle wrote: > Was planning to adding a hot spare to my 3 disk raid5 array and was > thinking if I go to 4 drives I would be a better off as 2 raid1 arrays > considering the current state of raid5. I just wonder about the comment "considering the current state of raid5". What might be wrong with raid5 currently? I certainly know a number of people (me included) who run several "large" raid-5 arrays and don't have any problems. Brad -- "Human beings, who are almost unique in having the ability to learn from the experience of others, are also remarkable for their apparent disinclination to do so." -- Douglas Adams - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Convert raid5 to raid1?
Brad Campbell wrote: John McMonagle wrote: I just wonder about the comment "considering the current state of raid5". What might be wrong with raid5 currently? Perhaps he's referring to the possibility of undetectable data corruption that can occur with software raid5? Granted, there's a very small chance of it happening, but if your array becomes degraded (i.e., you lose a disk, which with the way md currently works, only takes one bad block) and then you have a server crash (or other unclean shutdown of your array), you likely will suffer data corruption. See this for more details: http://www.cs.helsinki.fi/linux/linux-kernel/2002-19/0906.html -- Paul - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Convert raid5 to raid1?
Brad Not saying its broke. Part of my reasoning to go to raid5 was that I could expand. While it can be done I don't really see it as practical. Also it's looking like I probably will not need to expand. raid5 with 3 drives and 1 spare or 2 - 2 drive raid1 drives have the same space. Which is less likely to have a failure cause data loss? I'm guessing raid1. If I'm wrong I'd like to know now. Also concerned about the resync times. It was going to take a couple days to resync under a rather light load if it weren't for the fact that it couldn't because of a bad drive and a kernel panic caused by the read error. Still not certain about the cause of problem my current guess is the sata controller. I'm glad there is work being done on the resync issue. Also think the ideas to attempt to fix read errors are great. My only suggestion is that there should be provision to send notification when it happens. With both that would really help. John Brad Campbell wrote: John McMonagle wrote: Was planning to adding a hot spare to my 3 disk raid5 array and was thinking if I go to 4 drives I would be a better off as 2 raid1 arrays considering the current state of raid5. I just wonder about the comment "considering the current state of raid5". What might be wrong with raid5 currently? I certainly know a number of people (me included) who run several "large" raid-5 arrays and don't have any problems. Brad - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
RE: Convert raid5 to raid1?
You asked: "raid5 with 3 drives and 1 spare or 2 - 2 drive raid1 drives have the same space. Which is less likely to have a failure cause data loss?" Assume 4 drives. With RAID5 using 3 drives and 1 spare... == If a disk is kicked out because of a bad block, a re-build starts, no problem here. Data redundancy is lost until the re-build finishes. If during the re-build, a second bad block exists on any of the 2 remaining disk, then another disk is kicked out. You array is now down. The data can be recovered, but it is tricky. With RAID 1+0, 4 disks no spare. == If a disk is kicked out because of a bad block, no problem. Data redundancy is lost until the fail disk is replaced and a re-build finishes. Now only 1 of the remaining 3 disks has high risk. If that disk gets a bad block, game over, the array goes off-line, however, the data is not really lost and can be recovered, but still tricky. == With RAID 1, 1+0 and 5 if the 2 bad blocks occur on the same stripe, then the data on the bad blocks is really gone, but that is very un-likely. So, IMO, RAID5 has a higher risk of going off-line do to multi block (multi disk) failures. RAID1 has less risk. Assuming the same number of disks. Also, as the number of disks increases, the risk of failure on RAID5 goes up, and the risk on RAID1 goes down. RAID6 can survive 2 failed disks, very unlikely to have 2 more bad blocks during a re-sync. However, RAID6 with 3 disks and 1 spare is useless. But RAID6 with 4 disks should be more reliable than RAID1+0. But I am not convinced RAID6 is stable yet. Others disagree with me. I hope they are correct. Raid1+0 and RAID10 are similar, but different. RAID1+0 is a RAID0 array made up of 2 or more RAID1 arrays. Each RAID1 array could lose 1 disk and the RAID0 array should continue to function. RAID10 supports an odd number of disks. In the case of an odd number of disks, only 1 disk can fail, or the array goes off-line. In the case of an even number of disks, I am not sure how many disks can fail with out the array going off-line. RAID10 is also new, but I have not heard anything bad (or good) about it. Anything I say is my opinion. My opinions are the best! :) Guy -Original Message- From: [EMAIL PROTECTED] [mailto:[EMAIL PROTECTED] On Behalf Of John McMonagle Sent: Thursday, March 10, 2005 7:02 PM To: Brad Campbell Cc: linux-raid@vger.kernel.org Subject: Re: Convert raid5 to raid1? Brad Not saying its broke. Part of my reasoning to go to raid5 was that I could expand. While it can be done I don't really see it as practical. Also it's looking like I probably will not need to expand. raid5 with 3 drives and 1 spare or 2 - 2 drive raid1 drives have the same space. Which is less likely to have a failure cause data loss? I'm guessing raid1. If I'm wrong I'd like to know now. Also concerned about the resync times. It was going to take a couple days to resync under a rather light load if it weren't for the fact that it couldn't because of a bad drive and a kernel panic caused by the read error. Still not certain about the cause of problem my current guess is the sata controller. I'm glad there is work being done on the resync issue. Also think the ideas to attempt to fix read errors are great. My only suggestion is that there should be provision to send notification when it happens. With both that would really help. John Brad Campbell wrote: > John McMonagle wrote: > >> Was planning to adding a hot spare to my 3 disk raid5 array and was >> thinking if I go to 4 drives I would be a better off as 2 raid1 >> arrays considering the current state of raid5. > > > I just wonder about the comment "considering the current state of > raid5". What might be wrong with raid5 currently? I certainly know a > number of people (me included) who run several "large" raid-5 arrays > and don't have any problems. > > Brad - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
Re: Problems with Linux RAID in kernel 2.6
On Thursday March 10, [EMAIL PROTECTED] wrote: > Hi, > > I have many problems with RAID in kernel 2.6.10. .. > And dmesg says: > > md: raidstart(pid 2944) used deprecated START_ARRAY ioctl. This will not > <-- !!! > be supported beyond 2.6 > <-- !!! Take the hint. Don't use 'raidstart'. It seems to work, but it will fail you when it really counts. In fact, I think it is failing for you now. Use mdadm to assemble your arrays. > > And with mdadm also fails: > > centralmad:~# mdadm -R /dev/md2 > mdadm: failed to run array /dev/md2: Invalid argument You are using mdadm wrongly. You want something like: mdadm --assemble /dev/md2 /dev/sdb2 /dev/sdc2 > centralmad:~# cat /proc/mdstat > Personalities : [raid1] > unused devices: > > Moreover, dmesg says the md driver fails: > > md: bug in file drivers/md/md.c, line 1514 This is (a rather non-helpful) way of saying that you tried to start an array which contained no devices. NeilBrown - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to [EMAIL PROTECTED] More majordomo info at http://vger.kernel.org/majordomo-info.html
