Re: argh!

On 31/10/2010 21:44, Neil Brown wrote:
> On Sun, 31 Oct 2010 21:18:52 +0000
> Jon Hardcastle<jonathan.hardcastle <at> gmail.com>  wrote:
>
>> Hi,
>>
>> Thanks for your help. I use 0.90 as that is what there was when the
>> machine was build ~3yrs ago.. the array has been grown and resized
>> since then.
>>
>> Does anyone have a feature list for the superblocks? Why upgrade.....?
>
> The "md" man page mentions a couple of differences:
>    - v1.x can handle more than 28 devices in an array
>    - v1.x can easily be moved between hosts with different endian-ness
>    - v1.x can put the metadata at the front of the array
>
> I should probably add the other differences.
>
>    - with 0.90 there can be confusion about whether a superblock applies
>      to the whole device or to just the last partition (if it start on a
>      64K boundary).  1.x doesn't have that problem
>    - With 1.x a device recovery can be checkpointed and restarted.
>    - with 0.90, the maximum component for RAID1 or higher is 2TB (or maybe
>      4TB, not sure).  With 1.x you can go much higher.

Aha. Some other good info for me to perhaps incorporate if I ever get 
round to trying to patch the man page. In fact I probably ought to 
review the last few months' list postings, and especially Neil B's.

Re: Samsung F1 RAID Class SATA/300 1TB drives

Mark Knecht wrote:
> I saw in Fry's San Jose ad today they were selling these
> Serial-ATA/300 drives for $67. They didn't give a model number but
> scouting around a bit on the web I'm guessing they are a discontinued
> model.
>
> Any inputs on whether these are drives that work well with mdadm RAID?
> Do they support TLER and otherwise work well?
>
> This would just be a home server of some type, nothing industrial.
> Probably a 3 drive RAID-1 or something like that.
>
> Comments?
>    

Newegg has prices like that regularly. On brand name drives, like 
Seagate, Hitachi, and WD, too, if you prefer.

--

-- 
Bill Davidsen<davidsen <at> tmr.com>
   "We can't solve today's problems by using the same thinking we
    used in creating them." - Einstein

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Re: Samsung F1 RAID Class SATA/300 1TB drives

On Thu, Oct 28, 2010 at 4:37 PM, John Robinson
<john.robinson <at> anonymous.org.uk> wrote:
> On 29/10/2010 00:17, Mark Knecht wrote:
>> I saw in Fry's San Jose ad today they were selling these
>> Serial-ATA/300 drives for $67. They didn't give a model number but
>> scouting around a bit on the web I'm guessing they are a discontinued
>> model.
>>
>> Any inputs on whether these are drives that work well with mdadm RAID?
>> Do they support TLER and otherwise work well?
>>
>> This would just be a home server of some type, nothing industrial.
>> Probably a 3 drive RAID-1 or something like that.
>
> Well, they're perhaps not great. I bought three and after only about a
> thousand hours one of them was giving SMART errors, then after about 7,500
> hours a second one started doing it too. At that point I replaced both with
> other makes, copying over with ddrescue (or maybe it was dd_rescue), which
> worked without any failed sectors, then ran badblocks -w on the Samsungs and
> the SMART errors went away. The third one of mine is still fine, and the
> other two are now in a ReadyNAS giving good service.

I think that using two different brand drives in general is a good idea.

We recently had 2 500 GB WD5000AAKS drives die at the same time over a
weekend.  Both of them suffered from the same death and would no
longer spin up - just making a clicking/whirring sound when you
powered it on.

Luckily we had backups for most of the data on there, but some

RE: argh!

> I don't have backups as this is 4TB's of data and have never beeen
> able to afford having a whole second machine, but the price of drives
> has come down alot now so think I may build a noddy machine for weekly
> backups.

	4T worth of backup space can be had for $200.  If the data is not
worth $200 to you, then by all means you are free to ignore the need for
backup, but eventually you will lose at least some, if not all, of the data.
Although an on-line backup system is very handy, it is not absolutely
essential.  You could employ dar or some similar utility to backup the data
to individual off-line disks, for example.

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RE: Samsung F1 RAID Class SATA/300 1TB drives

> -----Original Message-----
> From: linux-raid-owner <at> vger.kernel.org [mailto:linux-raid-
> owner <at> vger.kernel.org] On Behalf Of David Rees
> Sent: Monday, November 01, 2010 4:26 PM
> To: John Robinson
> Cc: Mark Knecht; Linux-RAID
> Subject: Re: Samsung F1 RAID Class SATA/300 1TB drives
> 
> On Thu, Oct 28, 2010 at 4:37 PM, John Robinson
> <john.robinson <at> anonymous.org.uk> wrote:
> > On 29/10/2010 00:17, Mark Knecht wrote:
> >> I saw in Fry's San Jose ad today they were selling these
> >> Serial-ATA/300 drives for $67. They didn't give a model number but
> >> scouting around a bit on the web I'm guessing they are a discontinued
> >> model.
> >>
> >> Any inputs on whether these are drives that work well with mdadm RAID?
> >> Do they support TLER and otherwise work well?
> >>
> >> This would just be a home server of some type, nothing industrial.
> >> Probably a 3 drive RAID-1 or something like that.
> >
> > Well, they're perhaps not great. I bought three and after only about a
> > thousand hours one of them was giving SMART errors, then after about
> 7,500
> > hours a second one started doing it too. At that point I replaced both
> with
> > other makes, copying over with ddrescue (or maybe it was dd_rescue),
> which
> > worked without any failed sectors, then ran badblocks -w on the Samsungs

status of sas1068 ata-passthrough bug?

I've seen a few mentions on this list of kernel bug 14831 / 13594,
where drives on an LSI SAS1068 controller are dropped when smartd is
run:

https://bugzilla.kernel.org/show_bug.cgi?id=14831
https://bugzilla.kernel.org/show_bug.cgi?id=13594

I was just wondering if this bug is "officially" fixed, and if so, in
what kernel version?  The Bugzilla entries above don't show it as
fixed, but I saw on this list someone mentioned that it's fixed in
2.6.36 (I think---I can't find that post now).

Thanks,
Matt
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Re: reshape success story

On 31/10/2010 15:46, Neil Brown wrote:
> On Sun, 31 Oct 2010 14:19:13 +0000
> John Robinson<john.robinson <at> anonymous.org.uk>  wrote:
[...]
>> Perhaps the man page needs updating then.
[...]
>> If I've got the above right (someone please correct me if I'm not)
>> perhaps I could make a modest contribution (for a change) by updating/
>> patching the man page...
>
> That would certainly be appreciated.   Your understanding appear to be
> correct!

Is the attached of any use? I started with 3.1.4. I've fixed a couple of 
typos as well as hopefully improving the explanations about backup files 
and reshapes, and added a couple of your remarks about metadata types 
from another thread. Some of the text was cribbed from your blog about 
reshaping.

Cheers,

John.

--- a/mdadm.8.in	2010-08-31 08:21:13.000000000 +0100
+++ b/mdadm.8.in	2010-11-02 01:05:44.000000000 +0000
 <at>  <at>  -322,16 +322,20  <at>  <at> 
 ..
 Use the original 0.90 format superblock.  This format limits arrays to
 28 component devices and limits component devices of levels 1 and

Upgraded grub, now confused about mirrored /boot

Hello,

	I upgraded my system from Red Hat FC10 to FC11.  The instructions
say to run this command:
/sbin/grub-install BOOTDEVICE

And if it fails, run this:
/sbin/grub-install --recheck /dev/sda

However, my boot disk (/boot) is mirrored on 4 disks and I think (or hope)
all 4 are bootable.  The mirrors were created at install time many years ago
when I installed FC5.  No idea if it really made more than 1 bootable.  I
have assumed that if sda failed, I could still boot from sdb, sdc or sdd.
And I do understand that I might need to remove sda first, depending on the
type of failure.  Lucky for me, no drive has failed yet and I don't recall
if I tested booting off of any other disks.

I do have this on the kernel line:
md-mod.start_dirty_degraded=1

So, what do I do now?  Run that command on all 4 disks?  Or run it on
/dev/md0?

Oh, 4 way mirror is not because I am paranoid.  I have 4 disks partitioned
alike, so I figured I would use all 4 disks just for the symmetry.  OCD
maybe, but not paranoid.  :)

# df -k /boot
Filesystem           1K-blocks      Used Available Use% Mounted on
/dev/md0                256586    221526     21812  92% /boot

RE: Upgraded grub, now confused about mirrored /boot

> -----Original Message-----
> From: linux-raid-owner <at> vger.kernel.org [mailto:linux-raid-
> owner <at> vger.kernel.org] On Behalf Of Guy Watkins
> Sent: Tuesday, November 02, 2010 1:11 AM
> To: 'Linux RAID'
> Subject: Upgraded grub, now confused about mirrored /boot
> 
> Hello,
> 
> 	I upgraded my system from Red Hat FC10 to FC11.  The instructions
> say to run this command:
> /sbin/grub-install BOOTDEVICE
> 
> And if it fails, run this:
> /sbin/grub-install --recheck /dev/sda
> 
> However, my boot disk (/boot) is mirrored on 4 disks and I think (or hope)
> all 4 are bootable.  The mirrors were created at install time many years
> ago
> when I installed FC5.  No idea if it really made more than 1 bootable.  I
> have assumed that if sda failed, I could still boot from sdb, sdc or sdd.
> And I do understand that I might need to remove sda first, depending on
> the
> type of failure.  Lucky for me, no drive has failed yet and I don't recall
> if I tested booting off of any other disks.
> 
> I do have this on the kernel line:
> md-mod.start_dirty_degraded=1
> 
> So, what do I do now?  Run that command on all 4 disks?  Or run it on