Re: patches for mdadm 1.8.0 (auto=dev and stacking of devices)

2005-01-23 Thread Michael Tokarev
Lars Marowsky-Bree wrote: On 2005-01-23T16:13:05, Luca Berra [EMAIL PROTECTED] wrote: the first one adds an auto=dev parameter rationale: udev does not create /dev/md* device files, so we need a way to create them when assembling the md device. Am I missing something but shouldn't this be fixed by

Re: *terrible* direct-write performance with raid5

2005-02-22 Thread Michael Tokarev
Peter T. Breuer wrote: Michael Tokarev [EMAIL PROTECTED] wrote: When debugging some other problem, I noticied that direct-io (O_DIRECT) write speed on a software raid5 And normal write speed (over 10 times the size of ram)? There's no such term as normal write speed in this context in my

Re: [OT] best tape backup system?

2005-02-22 Thread Michael Tokarev
Guy wrote: I have NOT been able to share a SCSI cable/card with disks and a tape drive. Tried for days. I would get disk errors, or timeouts. I corrected the problem by putting the tape drive on a dedicated SCSI bus/card. I don't recall the details of the failures, since it has been well over a

Re: *terrible* direct-write performance with raid5

2005-02-23 Thread Michael Tokarev
dean gaudet wrote: On Tue, 22 Feb 2005, Michael Tokarev wrote: When debugging some other problem, I noticied that direct-io (O_DIRECT) write speed on a software raid5 is terrible slow. Here's a small table just to show the idea (not numbers by itself as they vary from system to system but how

Re: [OT] best tape backup system?

2005-02-23 Thread Michael Tokarev
Guy wrote: I know a thing or 2 about SCSI. I know I had it correct. 1 config was all wide LVD (2940U2W). My card has a LVD and a SE port on the same logical SCSI bus. I was surprized once when I noticied such logical SCSI bus really isn't logical per se. I mean, if I plug ANY device into the

Severe, huge data corruption with softraid

2005-03-02 Thread Michael Tokarev
Too bad I can't diagnose the problem correctly, but it is here somewhere, and is (hardly) reproduceable. I'm doing alot of experiments right now with various raid options and read/write speed. And 3 times now, the whole system went boom during the experiments. It is writing into random places on

Re: Severe, huge data corruption with softraid

2005-03-02 Thread Michael Tokarev
Michael Tokarev wrote: [data corruption.. snip] And finally I managed to get an OOPs. Created fresh raid5 array out of 4 partitions, chunk size = 4kb. Created ext3fs on it. Tested write speed (direct-io) - it was terrible, about 6MB/sec for 64KB blocks - it's very unusual. Umounted the fs. Did

Re: [PERFORM] Postgres on RAID5

2005-03-14 Thread Michael Tokarev
Arshavir Grigorian wrote: Alex Turner wrote: [] Well, by putting the pg_xlog directory on a separate disk/partition, I was able to increase this rate to about 50 or so per second (still pretty far from your numbers). Next I am going to try putting the pg_xlog on a RAID1+0 array and see if that

Re: [PATCH 1/2] md bitmap bug fixes

2005-03-19 Thread Michael Tokarev
Peter T. Breuer wrote: Michael Tokarev [EMAIL PROTECTED] wrote: [] o For md, all drives are equal, that is, for example, raid1 code will balance reads among all the available drives a-la Not necessarily so. At least part of the FR1 patch is dedicated to timing the latencies of the disks

Robust Read (was: [PATCH 1/2] md bitmap bug fixes)

2005-03-19 Thread Michael Tokarev
Peter T. Breuer wrote: [] The patch was originally developed for 2.4, then ported to 2.6.3, and then to 2.6.8.1. Neil has recently been doing stuff, so I don't think it applies cleanly to 2.6.10, but somebody WAS porting it for me until they found that 2.6.10 didn't support their hardware ... and

Re: Robust Read

2005-03-19 Thread Michael Tokarev
Peter T. Breuer wrote: Michael Tokarev [EMAIL PROTECTED] wrote: [-- text/plain, encoding 7bit, charset: KOI8-R, 74 lines --] Uh-oh. Setting proper charset this time. What a nonsense: 7bit but koi8... ;) [] Uh OK. As I recall one only needs to count, one doesn't need a bitwise map of what one has

Re: Robust Read

2005-03-19 Thread Michael Tokarev
Peter T. Breuer wrote: Michael Tokarev [EMAIL PROTECTED] wrote: [] But your approach is fine - it's just that (a) I don't like to mess with the struct sizes, as that makes modules binary incompatible, instead of just having extra functionalities, and (b) I really think it's not going to be easily

interesting failure scenario

2005-04-03 Thread Michael Tokarev
I just come across an interesting situation, here's the scenario. 0. Have a RAID1 array composed of two components, d1 and d2. The array was running, clean, event counter was 10. 1. d1 failed (eg, hotplug-removed). 2. on d2's superblock we now have event=11, and d1 is marked as failed. 3. the

Don't use whole disks for raid arrays [was: Questions about software RAID]

2005-04-19 Thread Michael Tokarev
A followup about one single question. tmp wrote: [] Is it correct that I can use whole disks (/dev/hdb) only if I make a partitionable array and thus creates the partitions UPON the raid mechanism? Just don't use whole disks for md arrays. *Especially* if you want to create partitions inside the

Re: Questions about software RAID

2005-04-19 Thread Michael Tokarev
David Greaves wrote: Luca Berra wrote: many people find it easier to understand if raid partitions are set to 0XFD. kernel autodetection is broken and should not be relied upon. Could you clarify what is broken? I understood that it was simplistic (ie if you have a raid0 built over a raid5 or

Re: skip raid5 reconstruction

2005-07-06 Thread Michael Tokarev
Ming Zhang wrote: Hi folks I am testing some HW performance with raid5 with 2.4.x kenrel. It is really troublesome every time I create a raid5, wait 4 hours for reconstruction, and then test some data and then recreate another one and wait again. I wonder if there is any hack or option

[patch] linear does not need chunksize

2005-07-16 Thread Michael Tokarev
the change). Note chunk size is never used on linear array. The only usage of chunk_size member is in /proc/mdstat, as rounding parameter (linear.c) - looks like it should be removed too. Signed-Off-By: Michael Tokarev [EMAIL PROTECTED] --- linux-2.6.12/drivers/md/md.c.orig 2005-06-17 23:48

Re: [patch] linear does not need chunksize

2005-07-16 Thread Michael Tokarev
Neil Brown wrote: On Sunday July 17, [EMAIL PROTECTED] wrote: [] Note chunk size is never used on linear array. The only usage of chunk_size member is in /proc/mdstat, as rounding parameter (linear.c) - looks like it should be removed too. This statement isn't entirely true, though it took

Re: [PATCH] proactive raid5 disk replacement for 2.6.11, updated

2005-08-18 Thread Michael Tokarev
Neil Brown wrote: Thanks for this. There are definitely some good ideas here. However I think I would like to do it a little bit differently. If we want to mirror a single drive in a raid5 array, I would really like to do that using the raid1 personality. e.g. suspend io remove the

Re: Where is the performance bottleneck?

2005-08-31 Thread Michael Tokarev
Holger Kiehl wrote: On Wed, 31 Aug 2005, Jens Axboe wrote: On Wed, Aug 31 2005, Holger Kiehl wrote: [] I used the following command reading from all 8 disks in parallel: dd if=/dev/sd?1 of=/dev/null bs=256k count=78125 Here vmstat output (I just cut something out in the middle):

Re: 2 partition kicked from 6 raid5

2005-08-31 Thread Michael Tokarev
Deak Krisztian wrote: Hi, i have a big problem. A had a sw raid5 array with 6 partition. The array has been damaged because problems of power connectors. 2 partitions/disks don't work, because during the time the SATA power connections didn't work. Some write/read operations where running.

Re: raid5: Disk failure on sdm, disabling device

2005-08-31 Thread Michael Tokarev
David M. Strang wrote: [] It's a SCSI drive; in's a Dell 220F enclosure connected via a QLA2200 adapter. I've pulled the bad disk (tho not 'yellow' at the hardware level; and re-inserted it -- but to no avail. It did cause a reset; but the device remains 'disabled'. Aug 31 11:48:05 abyss

Re: raid5: Disk failure on sdm, disabling device

2005-08-31 Thread Michael Tokarev
David M. Strang wrote: [] Is there something a little deeper to this error message? Aug 31 04:48:15 abyss kernel: scsi2 (12:0): rejecting I/O to offline device Aug 31 04:48:15 abyss kernel: raid5: Disk failure on sdm, disabling device. If you reread my message, I hope you will find a bit of

Re: mdadm 2.1: command line option parsing bug?

2005-11-22 Thread Michael Tokarev
Neil Brown wrote: [] I would like it to take an argument in contexts where --bitmap was meaningful (Create, Assemble, Grow) and not where --brief is meaningful (Examine, Detail). but I don't know if getopt_long will allow the 'short_opt' string to be changed half way through processing...

mdadm --size and --update=uuid etc options...

2005-12-05 Thread Michael Tokarev
I found it's quite difficult, after resizing underlying partitions, to compute the new size for mdadm /dev/mdX -G --size=xyz command, because of the way how it finds the superblock offset. So, the question is -- is it possible to make the argument of --size to be optional, and let mdadm to

Re: corrupt raid 5

2006-01-04 Thread Michael Tokarev
Lorac Thelmwood wrote: Seatools is a DOS based tool. It doesn't matter what OS you have. It just examines the drives themselves, not the filesystem. It is used to check if your drives are bad. FYI, seatools package is available for linux too, linux version can be found at the same place on

Re: [PATCH 000 of 5] md: Introduction

2006-01-17 Thread Michael Tokarev
NeilBrown wrote: Greetings. In line with the principle of release early, following are 5 patches against md in 2.6.latest which implement reshaping of a raid5 array. By this I mean adding 1 or more drives to the array and then re-laying out all of the data. Neil, is this online

Re: [PATCH 000 of 5] md: Introduction

2006-01-17 Thread Michael Tokarev
Sander wrote: Michael Tokarev wrote (ao): [] Neil, is this online resizing/reshaping really needed? I understand all those words means alot for marketing persons - zero downtime, online resizing etc, but it is much safer and easier to do that stuff 'offline', on an inactive array, like raidreconf

Re: [PATCH 000 of 5] md: Introduction

2006-01-17 Thread Michael Tokarev
Ross Vandegrift wrote: On Tue, Jan 17, 2006 at 02:26:11PM +0300, Michael Tokarev wrote: Raid code is already too fragile, i'm afraid simple I/O errors (which is what we need raid for) may crash the system already, and am waiting for the next whole system crash due to eg superblock update error

Terrible slow write speed to MegaRAID SCSI array

2006-03-18 Thread Michael Tokarev
We've installed an LSI Logic MegaRaid SCSI 320-1 card on our server (used only temporarily to move data to larger disks, but that's not the point), and measured linear write performance, just to know how much time it will took to copy our (somewhat large) data to the new array. And to my

Re: linear writes to raid5

2006-04-18 Thread Michael Tokarev
Neil Brown wrote: [] raid5 shouldn't need to merge small requests into large requests. That is what the 'elevator' or io_scheduler algorithms are for. There already merge multiple bio's into larger 'requests'. If they aren't doing that, then something needs to be fixed. It is certainly

Re: accessing mirrired lvm on shared storage

2006-04-18 Thread Michael Tokarev
Neil Brown wrote: [] Very cool... that would be extremely nice to have. Any estimate on when you might get to this? I'm working on it, but there are lots of distractions Neil, is there anything you're NOT working on? ;) Sorry just can't resist... ;) /mjt - To unsubscribe from this

Re: linear writes to raid5

2006-04-20 Thread Michael Tokarev
Neil Brown wrote: On Tuesday April 18, [EMAIL PROTECTED] wrote: [] I mean, mergeing bios into larger requests makes alot of sense between a filesystem and md levels, but it makes alot less sense to do that between md and physical (fsvo physical anyway) disks. This seems completely backwards

Re: problems with raid=noautodetect

2006-05-29 Thread Michael Tokarev
Neil Brown wrote: On Friday May 26, [EMAIL PROTECTED] wrote: [] If we assume there is a list of devices provided by a (possibly default) 'DEVICE' line, then DEVICEFILTER !pattern1 !pattern2 pattern3 pattern4 could mean that any device in that list which matches pattern 1 or 2 is

Re: New FAQ entry? (was IBM xSeries stop responding during RAID1 reconstruction)

2006-06-21 Thread Michael Tokarev
Niccolo Rigacci wrote: [] From the command line you can see which schedulers are supported and change it on the fly (remember to do it for each RAID disk): # cat /sys/block/hda/queue/scheduler noop [anticipatory] deadline cfq # echo cfq /sys/block/hda/queue/scheduler Otherwise

Re: [PATCH] enable auto=yes by default when using udev

2006-07-04 Thread Michael Tokarev
Neil Brown wrote: On Monday July 3, [EMAIL PROTECTED] wrote: Hello, the following patch aims at solving an issue that is confusing a lot of users. when using udev, device files are created only when devices are registered with the kernel, and md devices are registered only when started.

Re: Grub vs Lilo

2006-07-26 Thread Michael Tokarev
Jason Lunz wrote: [EMAIL PROTECTED] said: Wondering if anyone can comment on an easy way to get grub to update all components in a raid1 array. I have a raid1 /boot with a raid10 /root and have previously used lilo with the raid-extra-boot option to install to boot sectors of all component

Re: Grub vs Lilo

2006-07-26 Thread Michael Tokarev
Bernd Rieke wrote: Michael Tokarev wrote on 26.07.2006 20:00: . . The thing with all this my RAID devices works, it is really simple! thing is: for too many people it indeed works, so they think it's good and correct way. But it works up to the actual failure, which, in most setups

Re: [PATCH 006 of 9] md: Remove the working_disks and failed_disks from raid5 state data.

2006-07-31 Thread Michael Tokarev
NeilBrown wrote: They are not needed. conf-failed_disks is the same as mddev-degraded By the way, `failed_disks' is more understandable than `degraded' in this context. Degraded usually refers to the state of the array in question, when failed_disks 0. That to say: I'd rename degraded back

Re: let md auto-detect 128+ raid members, fix potential race condition

2006-08-01 Thread Michael Tokarev
Alexandre Oliva wrote: [] If mdadm can indeed scan all partitions to bring up all raid devices in them, like nash's raidautorun does, great. I'll give that a try, Never, ever, try to do that (again). Mdadm (or vgscan, or whatever) should NOT assemble ALL arrays found, but only those which it

Re: Converting Ext3 to Ext3 under RAID 1

2006-08-03 Thread Michael Tokarev
Paul Clements wrote: Is 16 blocks a large enough area? Maybe. The superblock will be between 64KB and 128KB from the end of the partition. This depends on the size of the partition: SB_LOC = PART_SIZE - 64K - (PART_SIZE (64K-1)) So, by 16 blocks, I assume you mean 16 filesystem

Re: modifying degraded raid 1 then re-adding other members is bad

2006-08-08 Thread Michael Tokarev
Neil Brown wrote: On Tuesday August 8, [EMAIL PROTECTED] wrote: Assume I have a fully-functional raid 1 between two disks, one hot-pluggable and the other fixed. If I unplug the hot-pluggable disk and reboot, the array will come up degraded, as intended. If I then modify a lot of the data

Re: [bug?] raid1 integrity checking is broken on 2.6.18-rc4

2006-08-12 Thread Michael Tokarev
Justin Piszcz wrote: Is there a doc for all of the options you can echo into the sync_action? I'm assuming mdadm does these as well and echo is just another way to run work with the array? How about the obvious, Documentation/md.txt ? And no, mdadm does not perform or trigger data integrity

spurious dots in dmesg when reconstructing arrays

2006-08-17 Thread Michael Tokarev
A long time ago I noticied pretty bad formatting of dmesg text in md array reconstruction output, but never bothered to ask. So here it goes. Example dmesg (RAID conf printout sections omitted): md: bindsdb1 RAID1 conf printout: ..6md: syncing RAID array md1 md: minimum _guaranteed_

Re: Feature Request/Suggestion - Drive Linking

2006-09-03 Thread Michael Tokarev
Tuomas Leikola wrote: [] Here's an alternate description. On first 'unrecoverable' error, the disk is marked as FAILING, which means that a spare is immediately taken into use to replace the failing one. The disk is not kicked, and readable blocks can still be used to rebuild other blocks

proactive-raid-disk-replacement

2006-09-08 Thread Michael Tokarev
Recently Dean Gaudet, in thread titled 'Feature Request/Suggestion - Drive Linking', mentioned his document, http://arctic.org/~dean/proactive-raid5-disk-replacement.txt I've read it, and have some umm.. concerns. Here's why: mdadm -Gb internal --bitmap-chunk=1024 /dev/md4 mdadm /dev/md4

Re: RAID5 fill up?

2006-09-08 Thread Michael Tokarev
Lars Schimmer wrote: Hi! I´ve got a software RAiD5 with 6 250GB HDs. Now I changed one disk after another to a 400GB HD and resynced the raid5 after each change. Now the RAID5 has got 6 400GB HDs and still uses only 6*250GB space. How can I grow the md0 device to use 6*400GB? mdadm --grow

Re: proactive-raid-disk-replacement

2006-09-08 Thread Michael Tokarev
dean gaudet wrote: On Fri, 8 Sep 2006, Michael Tokarev wrote: Recently Dean Gaudet, in thread titled 'Feature Request/Suggestion - Drive Linking', mentioned his document, http://arctic.org/~dean/proactive-raid5-disk-replacement.txt I've read it, and have some umm.. concerns. Here's why

Re: [BUG/PATCH] md bitmap broken on big endian machines

2006-09-28 Thread Michael Tokarev
Neil Brown wrote: [] Use ffz instead of find_first_set to convert multiplier to shift. From: Paul Clements [EMAIL PROTECTED] find_first_set doesn't find the least-significant bit on bigendian machines, so it is really wrong to use it. ffs is closer, but takes an 'int' and we have a

Re: [BUG/PATCH] md bitmap broken on big endian machines

2006-09-29 Thread Michael Tokarev
Paul Clements wrote: Michael Tokarev wrote: Neil Brown wrote: ffs is closer, but takes an 'int' and we have a 'unsigned long'. So use ffz(~X) to convert a chunksize into a chunkshift. So we don't use ffs(int) for an unsigned value because of int vs unsigned int, but we use ffz

Re: Simulating Drive Failure on Mirrored OS drive

2006-10-02 Thread Michael Tokarev
andy liebman wrote: Read up on the md-faulty device. Got any links to this? As I said, we know how to set the device as faulty, but I'm not convinced this is a good simulation of a drive that fails (times out, becomes unresponsive, etc.) Note that 'set device as faulty' is NOT the same

Re: avoiding the initial resync on --create

2006-10-11 Thread Michael Tokarev
Doug Ledford wrote: On Mon, 2006-10-09 at 15:10 -0400, Rob Bray wrote: [] Probably the best thing to do would be on create of the array, setup a large all 0 block of mem and repeatedly write that to all blocks in the array devices except parity blocks and use a large all 1 block for that.

Re: [PATCH] md: Fix bug where new drives added to an md array sometimes don't sync properly.

2006-10-12 Thread Michael Tokarev
Neil Brown wrote: [] Fix count of degraded drives in raid10. Signed-off-by: Neil Brown [EMAIL PROTECTED] --- .prev/drivers/md/raid10.c 2006-10-09 14:18:00.0 +1000 +++ ./drivers/md/raid10.c 2006-10-05 20:10:07.0 +1000 @@ -2079,7 +2079,7 @@ static int run(mddev_t *mddev)

mdadm: bitmaps not supported by this kernel?

2006-10-25 Thread Michael Tokarev
Another 32/64 bits issue, it seems. Running 2.6.18.1 x86-64 kernel and mdadm 2.5.3 (32 bit). # mdadm -G /dev/md1 --bitmap=internal mdadm: bitmaps not supported by this kernel. # mdadm -G /dev/md1 --bitmap=none mdadm: bitmaps not supported by this kernel. etc. Recompiling mdadm in 64bit mode

Re: [PATCH 001 of 6] md: Send online/offline uevents when an md array starts/stops.

2006-11-09 Thread Michael Tokarev
Neil Brown wrote: [/dev/mdx...] (much like how /dev/ptmx is used to create /dev/pts/N entries.) [] I have the following patch sitting in my patch queue (since about March). It does what you suggest via /sys/module/md-mod/parameters/MAGIC_FILE which is the only md-specific part of the /sys

Re: [PATCH 001 of 6] md: Send online/offline uevents when an md array starts/stops.

2006-11-09 Thread Michael Tokarev
Michael Tokarev wrote: Neil Brown wrote: [/dev/mdx...] [] An in any case, we have the semantic that opening an md device-file creates the device, and we cannot get rid of that semantic without a lot of warning and a lot of pain. And adding a new semantic isn't really going to help. I

Re: why not make everything partitionable?

2006-11-15 Thread Michael Tokarev
martin f krafft wrote: Hi folks, you cannot create partitions within partitions, but you can well use whole disks for a filesystem without any partitions. It's usually better to have a partition table in place, at least on x86. Just to stop possible confusion - be it from kernel, or from

Re: RAID1 root and swap and initrd

2006-12-16 Thread Michael Tokarev
Andre Majorel wrote: [] Thanks Jurriaan and Gordon. I think I may still be f*cked, however. The Lilo doc says you can't use raid-extra-boot=mbr-only if boot= does not point to a raid device. Which it doesn't because in my setup, boot=/dev/sda. Using boot=/dev/md5 would solve the

Re: RAID1 root and swap and initrd

2006-12-16 Thread Michael Tokarev
Andre Majorel wrote: [] So just move it to sda1 (or sda2, sda3) from sda5 Problem is, the disks are entirely used by an extended partition. There's nowhere to move sd?5 to. You're using raid, so you've at least two disk drives. remove one component off all your raid devices (second disk),

Re: RAID1 root and swap and initrd

2006-12-21 Thread Michael Tokarev
[A late follow-up] Bill Davidsen wrote: Michael Tokarev wrote: Andre Majorel wrote: [] Thanks Jurriaan and Gordon. I think I may still be f*cked, however. The Lilo doc says you can't use raid-extra-boot=mbr-only if boot= does not point to a raid device. Which it doesn't because in my

Re: Linux Software RAID 5 Performance Optimizations: 2.6.19.1: (211MB/s read 195MB/s write)

2007-01-12 Thread Michael Tokarev
Justin Piszcz wrote: Using 4 raptor 150s: Without the tweaks, I get 111MB/s write and 87MB/s read. With the tweaks, 195MB/s write and 211MB/s read. Using kernel 2.6.19.1. Without the tweaks and with the tweaks: # Stripe tests: echo 8192 /sys/block/md3/md/stripe_cache_size # DD

Re: raid5 software vs hardware: parity calculations?

2007-01-15 Thread Michael Tokarev
dean gaudet wrote: [] if this is for a database or fs requiring lots of small writes then raid5/6 are generally a mistake... raid10 is the only way to get performance. (hw raid5/6 with nvram support can help a bit in this area, but you just can't beat raid10 if you need lots of writes/s.)

Re: Kernel 2.6.19.2 New RAID 5 Bug (oops when writing Samba - RAID5)

2007-01-23 Thread Michael Tokarev
Justin Piszcz wrote: [] Is this a bug that can or will be fixed or should I disable pre-emption on critical and/or server machines? Disabling pre-emption on critical and/or server machines seems to be a good idea in the first place. IMHO anyway.. ;) /mjt - To unsubscribe from this list: send

Re: Kernel 2.6.19.2 New RAID 5 Bug (oops when writing Samba - RAID5)

2007-01-23 Thread Michael Tokarev
Justin Piszcz wrote: On Tue, 23 Jan 2007, Michael Tokarev wrote: Disabling pre-emption on critical and/or server machines seems to be a good idea in the first place. IMHO anyway.. ;) So bottom line is make sure not to use preemption on servers or else you will get weird spinlock

Re: Move superblock on partition resize?

2007-02-07 Thread Michael Tokarev
) for exactly this purpose. /mjt /* mdsuper: read or write a linux software raid superbloc (version 0.90) * from or to a given device. * * GPL. * Written by Michael Tokarev ([EMAIL PROTECTED]) */ #define _GNU_SOURCE #include sys/types.h #include stdio.h #include unistd.h #include errno.h #include

Re: nonzero mismatch_cnt with no earlier error

2007-02-24 Thread Michael Tokarev
Jason Rainforest wrote: I tried doing a check, found a mismatch_cnt of 8 (7*250Gb SW RAID5, multiple controllers on Linux 2.6.19.2, SMP x86-64 on Athlon64 X2 4200 +). I then ordered a resync. The mismatch_cnt returned to 0 at the start of As pointed out later it was repair, not resync.

Re: Raid 10 Problems?

2007-03-08 Thread Michael Tokarev
Jan Engelhardt wrote: [] The other thing is, the bitmap is supposed to be written out at intervals, not at every write, so the extra head movement for bitmap updates should be really low, and not making the tar -xjf process slower by half a minute. Is there a way to tweak the

Re: Swap initialised as an md?

2007-03-23 Thread Michael Tokarev
Bill Davidsen wrote: [] If you use RAID0 on an array it will be faster (usually) than just partitions, but any process with swapped pages will crash if you lose either drive. With RAID1 operation will be more reliable but no faster. If you use RAID10 the array will be faster and more reliable,

Re: s2disk and raid

2007-04-04 Thread Michael Tokarev
Neil Brown wrote: On Tuesday April 3, [EMAIL PROTECTED] wrote: [] After the power cycle the kernel boots, devices are discovered, among which the ones holding raid. Then we try to find the device that holds swap in case of resume and / in case of a normal boot. Now comes a crucial point. The

Re: Swapping out for larger disks

2007-05-08 Thread Michael Tokarev
Brad Campbell wrote: [] It occurs though that the superblocks would be in the wrong place for the new drives and I'm wondering if the kernel or mdadm might not find them. I once had a similar issue. And wrote a tiny program (a hack, sort of), to read or write md superblock from/to a component

Re: No such device on --remove

2007-05-08 Thread Michael Tokarev
Benjamin Schieder wrote: Hi list. md2 : inactive hdh5[4](S) hdg5[1] hde5[3] hdf5[2] 11983872 blocks [EMAIL PROTECTED]:~# mdadm -R /dev/md/2 mdadm: failed to run array /dev/md/2: Input/output error [EMAIL PROTECTED]:~# mdadm /dev/md/ 0 1 2 3 4 5 [EMAIL PROTECTED]:~# mdadm

Re: Recovery of software RAID5 using FC6 rescue?

2007-05-08 Thread Michael Tokarev
Mark A. O'Neil wrote: Hello, I hope this is the appropriate forum for this request if not please direct me to the correct one. I have a system running FC6, 2.6.20-1.2925, software RAID5 and a power outage seems to have borked the file structure on the RAID. Boot shows the following

Re: Recovery of software RAID5 using FC6 rescue?

2007-05-09 Thread Michael Tokarev
Nix wrote: On 8 May 2007, Michael Tokarev told this: BTW, for such recovery purposes, I use initrd (initramfs really, but does not matter) with a normal (but tiny) set of commands inside, thanks to busybox. So everything can be done without any help from external recovery CD. Very handy

Re: No such device on --remove

2007-05-09 Thread Michael Tokarev
Bernd Schubert wrote: Benjamin Schieder wrote: [EMAIL PROTECTED]:~# mdadm /dev/md/2 -r /dev/hdh5 mdadm: hot remove failed for /dev/hdh5: No such device md1 and md2 are supposed to be raid5 arrays. You are probably using udev, don't you? Somehow there's presently no /dev/hdh5, but to

Re: removed disk md-device

2007-05-09 Thread Michael Tokarev
Bernd Schubert wrote: Hi, we are presently running into a hotplug/linux-raid problem. Lets assume a hard disk entirely fails or a stupid human being pulls it out of the system. Several partitions of the very same hardisk are also part of linux-software raid. Also, /dev is managed by

RFC: dealing with bad blocks: another view

2007-06-13 Thread Michael Tokarev
Now MD subsystem does a very good job at trying to recover a bad block on a disk, by re-writing its content (to force drive to reallocate the block in question) and verifying it's written ok. But I wonder if it's worth the effort to go further than that. Now, md can use bitmaps. And a bitmap

Re: 3ware 9650 tips

2007-07-13 Thread Michael Tokarev
Joshua Baker-LePain wrote: [] Yep, hardware RAID -- I need the hot swappability (which, AFAIK, is still an issue with md). Just out of curiocity - what do you mean by swappability ? For many years we're using linux software raid, we had no problems with swappability of the component drives (in

Re: A raid in a raid.

2007-07-21 Thread Michael Tokarev
mullaly wrote: [] All works well until a system reboot. md2 appears to be brought up before md0 and md1 which causes the raid to start without two of its drives. Is there anyway to fix this? How about listing the arrays in proper order in mdadm.conf ? /mjt - To unsubscribe from this list:

Re: SWAP file on a RAID-10 array possible?

2007-08-15 Thread Michael Tokarev
Tomas France wrote: Thanks for the answer, David! I kind of think RAID-10 is a very good choice for a swap file. For now I will need to setup the swap file on a simple RAID-1 array anyway, I just need to be prepared when it's time to add more disks and transform the whole thing into

Re: Help: very slow software RAID 5.

2007-09-20 Thread Michael Tokarev
Dean S. Messing wrote: [] [] That's what attracted me to RAID 0 --- which seems to have no downside EXCEPT safety :-). So I'm not sure I'll ever figure out the right tuning. I'm at the point of abandoning RAID entirely and just putting the three disks together as a big LV and being done

Re: Backups w/ rsync

2007-09-29 Thread Michael Tokarev
Dean S. Messing wrote: Michael Tokarev writes: [] : the procedure is something like this: : : cd /backups : rm -rf tmp/ : cp -al $yesterday tmp/ : rsync -r --delete -t ... /filesystem tmp : mv tmp $today : : That is, link the previous backup to temp (which takes no space

Re: problem killing raid 5

2007-10-01 Thread Michael Tokarev
Daniel Santos wrote: I retried rebuilding the array once again from scratch, and this time checked the syslog messages. The reconstructions process is getting stuck at a disk block that it can't read. I double checked the block number by repeating the array creation, and did a bad block scan.

Re: problem killing raid 5

2007-10-01 Thread Michael Tokarev
Patrik Jonsson wrote: Michael Tokarev wrote: [] But in any case, md should not stall - be it during reconstruction or not. For this, I can't comment - to me it smells like a bug somewhere (md layer? error handling in driver? something else?) which should be found and fixed

Re: Journalling filesystem corruption fixed in between?

2007-10-03 Thread Michael Tokarev
Rustedt, Florian wrote: Hello list, some folks reported severe filesystem-crashes with ext3 and reiserfs on mdraid level 1 and 5. I guess much more strong evidience and details are needed. Without any additional information I for one can only make a (not-so-pleasant) guess about those some

Re: very degraded RAID5, or increasing capacity by adding discs

2007-10-08 Thread Michael Tokarev
Janek Kozicki wrote: Hello, Recently I started to use mdadm and I'm very impressed by its capabilities. I have raid0 (250+250 GB) on my workstation. And I want to have raid5 (4*500 = 1500 GB) on my backup machine. Hmm. Are you sure you need that much space on the backup, to start with?

Re: very degraded RAID5, or increasing capacity by adding discs

2007-10-09 Thread Michael Tokarev
Neil Brown wrote: On Tuesday October 9, [EMAIL PROTECTED] wrote: [] o During this reshape time, errors may be fatal to the whole array - while mdadm do have a sense of critical section, but the whole procedure isn't as much tested as the rest of raid code, I for one will not rely on it,

Re: Software RAID when it works and when it doesn't

2007-10-20 Thread Michael Tokarev
Justin Piszcz wrote: [] - 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 Justin, forgive me please, but can you learn to trim the original messages when

Re: Time to deprecate old RAID formats?

2007-10-20 Thread Michael Tokarev
Doug Ledford wrote: [] 1.0, 1.1, and 1.2 are the same format, just in different positions on the disk. Of the three, the 1.1 format is the safest to use since it won't allow you to accidentally have some sort of metadata between the beginning of the disk and the raid superblock (such as an

Re: Time to deprecate old RAID formats?

2007-10-20 Thread Michael Tokarev
John Stoffel wrote: Michael == Michael Tokarev [EMAIL PROTECTED] writes: [] Michael Well, I strongly, completely disagree. You described a Michael real-world situation, and that's unfortunate, BUT: for at Michael least raid1, there ARE cases, pretty valid ones, when one Michael NEEDS

Re: Time to deprecate old RAID formats?

2007-10-20 Thread Michael Tokarev
Justin Piszcz wrote: On Fri, 19 Oct 2007, Doug Ledford wrote: On Fri, 2007-10-19 at 13:05 -0400, Justin Piszcz wrote: [] Got it, so for RAID1 it would make sense if LILO supported it (the later versions of the md superblock) Lilo doesn't know anything about the superblock format,

Re: Time to deprecate old RAID formats?

2007-10-22 Thread Michael Tokarev
John Stoffel wrote: Michael == Michael Tokarev [EMAIL PROTECTED] writes: If you are going to mirror an existing filesystem, then by definition you have a second disk or partition available for the purpose. So you would merely setup the new RAID1, in degraded mode, using the new partition

Re: 2.6.23.1: mdadm/raid5 hung/d-state

2007-11-04 Thread Michael Tokarev
Justin Piszcz wrote: # ps auxww | grep D USER PID %CPU %MEMVSZ RSS TTY STAT START TIME COMMAND root 273 0.0 0.0 0 0 ?DOct21 14:40 [pdflush] root 274 0.0 0.0 0 0 ?DOct21 13:00 [pdflush] After several days/weeks,

Re: 2.6.23.1: mdadm/raid5 hung/d-state

2007-11-04 Thread Michael Tokarev
Justin Piszcz wrote: On Sun, 4 Nov 2007, Michael Tokarev wrote: [] The next time you come across something like that, do a SysRq-T dump and post that. It shows a stack trace of all processes - and in particular, where exactly each task is stuck. Yes I got it before I rebooted, ran

Re: man mdadm - suggested correction.

2007-11-05 Thread Michael Tokarev
Janek Kozicki wrote: [] Can you please add do the manual under 'SEE ALSO' a reference to /usr/share/doc/mdadm ? /usr/share/doc/mdadm is Debian-specific (well.. not sure it's really Debian (or something derived from it) -- some other distros may use the same naming scheme, too). Other

Re: assemble vs create an array.......

2007-11-30 Thread Michael Tokarev
Bryce wrote: [] mdadm -C -l5 -n5 -c128 /dev/md0 /dev/sdf1 /dev/sde1 /dev/sdg1 /dev/sdc1 /dev/sdd1 ... IF you don't have the configuration printout, then you're left with exhaustive brute force searching of the combinations You're missing a very important point -- --assume-clean option. For

Re: Kernel 2.6.23.9 / P35 Chipset + WD 750GB Drives (reset port)

2007-12-02 Thread Michael Tokarev
Justin Piszcz said: (by the date of Sun, 2 Dec 2007 04:11:59 -0500 (EST)) The badblocks did not do anything; however, when I built a software raid 5 and the performed a dd: /usr/bin/time dd if=/dev/zero of=fill_disk bs=1M I saw this somewhere along the way: [42332.936706] ata5.00:

external bitmaps.. and more

2007-12-06 Thread Michael Tokarev
I come across a situation where external MD bitmaps aren't usable on any standard linux distribution unless special (non-trivial) actions are taken. First is a small buglet in mdadm, or two. It's not possible to specify --bitmap= in assemble command line - the option seems to be ignored. But

Re: assemble vs create an array.......

2007-12-06 Thread Michael Tokarev
[Cc'd to xfs list as it contains something related] Dragos wrote: Thank you. I want to make sure I understand. [Some background for XFS list. The talk is about a broken linux software raid (the reason for breakage isn't relevant anymore). The OP seems to lost the order of drives in his

Re: ERROR] scsi.c: In function 'scsi_get_serial_number_page'

2007-12-19 Thread Michael Tokarev
Thierry Iceta wrote: Hi I would like to use raidtools-1.00.3 on Rhel5 distribution but I got thie error Use mdadm instead. Raidtools is dangerous/unsafe, and is not maintained for a long time already. /mjt - To unsubscribe from this list: send the line unsubscribe linux-raid in the body of

Re: raid10: unfair disk load?

2007-12-21 Thread Michael Tokarev
Michael Tokarev wrote: I just noticed that with Linux software RAID10, disk usage isn't equal at all, that is, most reads are done from the first part of mirror(s) only. Attached (disk-hour.png) is a little graph demonstrating this (please don't blame me for poor choice of colors

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