Should I be Worried: sda: p1 size .... limited to end of disk

Should I be Worried: sda: p1 size .... limited to end of disk

[Eddie]

After the fun and games with my other LSI MegaRAID card, I'm a glutton 
for punishment.

I'm building another system, which this time, has an LSI MegaRAID SATA 
300-8X controller in it.  This appears to be working perfectly, and a 
lot faster than my other card, with the exception of this warning 
message during boot:

sda: p1 size 2930304132 limited to end of disk

Is this something I should be worried about, and how does it come 
about.  I built a new RAID 5, Logical device, on the card, which the LSI 
utility says is 1430511MB in size.

Here's the relevant output from DMESG:

scsi 4:1:0:0: Direct-Access     MegaRAID LD 0 RAID5 1430G 815C PQ: 0 ANSI: 2
sd 4:1:0:0: [sda] 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)
sd 4:1:0:0: [sda] Write Protect is off
sd 4:1:0:0: [sda] Mode Sense: 00 00 00 00
sd 4:1:0:0: [sda] Asking for cache data failed
sd 4:1:0:0: [sda] Assuming drive cache: write through
sd 4:1:0:0: [sda] 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)
sd 4:1:0:0: [sda] Write Protect is off
sd 4:1:0:0: [sda] Mode Sense: 00 00 00 00
sd 4:1:0:0: [sda] Asking for cache data failed
sd 4:1:0:0: [sda] Assuming drive cache: write through
 sda: sda1
sda: p1 size 2930304132 limited to end of disk
sd 4:1:0:0: [sda] Attached SCSI disk
sd 4:1:0:0: Attached scsi generic sg1 type 0

And /proc/partions:

major minor  #blocks  name

   3        0   20044080 hda
   3        1    9727326 hda1
   3        2    9727357 hda2
   3        4     586372 hda4
   8        0 1464843264 sda
   8        1 1464843232 sda1
 253        0  314572800 dm-0
 253        1  157286400 dm-1
 253        2  209715200 dm-2
 253        3  104857600 dm-3
 253        4  104857600 dm-4
 253        5  262144000 dm-5


And fdisk:

Disk /dev/sda: 1499.9 GB, 1499999502336 bytes
255 heads, 63 sectors/track, 182364 cylinders
Units = cylinders of 16065 * 512 = 8225280 bytes
Disk identifier: 0x0003d809

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1               1      182403  1465152066   8e  Linux LVM

So, where is the discrepancy creeping in.

Also, I see this in DMESG:

sd 4:1:0:0: [sda] Assuming drive cache: write through

But, as this card has a battery backup, I have it set to "Write Back" in 
the configuration.  So, what mode is it really operating in.

Cheers,
Eddie

Re: Should I be Worried: sda: p1 size .... limited to end of disk

[Grant Grundler]

On Sat, Oct 10, 2009 at 12:45 PM, Eddie <stunnel@attglobal.net> wrote:
> After the fun and games with my other LSI MegaRAID card, I'm a glutton for
> punishment.
>
> I'm building another system, which this time, has an LSI MegaRAID SATA
> 300-8X controller in it.  This appears to be working perfectly, and a lot
> faster than my other card, with the exception of this warning message during
> boot:
>
> sda: p1 size 2930304132 limited to end of disk

sda only has 2929686528 blocks - "p1" is somehow defined to go past
the end of the RAID "device".

I've no clue where the "2930304132" is coming from. I'd want to see
the "raw" values the partition table.
Seems like the partition table was written with the wrong size,

> Is this something I should be worried about, and how does it come about.  I
> built a new RAID 5, Logical device, on the card, which the LSI utility says
> is 1430511MB in size.

1430511*1024*2
2929686528

>
> Here's the relevant output from DMESG:
>
> scsi 4:1:0:0: Direct-Access     MegaRAID LD 0 RAID5 1430G 815C PQ: 0 ANSI: 2
> sd 4:1:0:0: [sda] 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)
> sd 4:1:0:0: [sda] Write Protect is off
> sd 4:1:0:0: [sda] Mode Sense: 00 00 00 00
> sd 4:1:0:0: [sda] Asking for cache data failed
> sd 4:1:0:0: [sda] Assuming drive cache: write through
> sd 4:1:0:0: [sda] 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)
> sd 4:1:0:0: [sda] Write Protect is off
> sd 4:1:0:0: [sda] Mode Sense: 00 00 00 00
> sd 4:1:0:0: [sda] Asking for cache data failed
> sd 4:1:0:0: [sda] Assuming drive cache: write through
> sda: sda1
> sda: p1 size 2930304132 limited to end of disk
> sd 4:1:0:0: [sda] Attached SCSI disk
> sd 4:1:0:0: Attached scsi generic sg1 type 0
>
> And /proc/partions:
>
> major minor  #blocks  name
>
>  3        0   20044080 hda
>  3        1    9727326 hda1
>  3        2    9727357 hda2
>  3        4     586372 hda4
>  8        0 1464843264 sda
>  8        1 1464843232 sda1
> 253        0  314572800 dm-0
> 253        1  157286400 dm-1
> 253        2  209715200 dm-2
> 253        3  104857600 dm-3
> 253        4  104857600 dm-4
> 253        5  262144000 dm-5
>
>
> And fdisk:
>
> Disk /dev/sda: 1499.9 GB, 1499999502336 bytes
> 255 heads, 63 sectors/track, 182364 cylinders
> Units = cylinders of 16065 * 512 = 8225280 bytes
> Disk identifier: 0x0003d809
>
>  Device Boot      Start         End      Blocks   Id  System
> /dev/sda1               1      182403  1465152066   8e  Linux LVM
>
> So, where is the discrepancy creeping in.

Can you print this using "Units of Blocks" instead of "Cyclinders"?
Use "-u" parameter.

hth,
grant

>
> Also, I see this in DMESG:
>
> sd 4:1:0:0: [sda] Assuming drive cache: write through
>
> But, as this card has a battery backup, I have it set to "Write Back" in the
> configuration.  So, what mode is it really operating in.
>
> Cheers,
> Eddie
>
> --
> To unsubscribe from this list: send the line "unsubscribe linux-scsi" in
> the body of a message to majordomo@vger.kernel.org
> More majordomo info at  http://vger.kernel.org/majordomo-info.html
>
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Re: Should I be Worried: sda: p1 size .... limited to end of disk

[Eddie]

Grant Grundler wrote:
> On Sat, Oct 10, 2009 at 12:45 PM, Eddie <stunnel@attglobal.net> wrote:
>   
>> After the fun and games with my other LSI MegaRAID card, I'm a glutton for
>> punishment.
>>
>> I'm building another system, which this time, has an LSI MegaRAID SATA
>> 300-8X controller in it.  This appears to be working perfectly, and a lot
>> faster than my other card, with the exception of this warning message during
>> boot:
>>
>> sda: p1 size 2930304132 limited to end of disk
>>     
>
> sda only has 2929686528 blocks - "p1" is somehow defined to go past
> the end of the RAID "device".
>
> I've no clue where the "2930304132" is coming from. I'd want to see
> the "raw" values the partition table.
> Seems like the partition table was written with the wrong size,
>   
The raw partition table entry is:

00 01 01 00 8E FE FF FF 3F 00 00 00 84 E4 A8 AE

Active Flag = 00
Starting Head = 01
Starting Cylinder = 0001
Partition Type = x'8E' - Linux LVM
Ending Head = x'FE' - 254
Ending Cylinder/Sector = x'FFFF' - LBA
Offset to Start = x'0000003F' - 63
# of Sectors = x'AEA8E484' - 2930304132 - Hmmmmmmm

So, that looks like the culprit.  Now, how did it happen.  I know I can, 
sort of safely, rebuild that, by running (c)fdisk and making sure I 
start the partition at exactly the same point.  But all I did the first 
time, was use cfdisk, and allocate the complete disk to the 1st primary 
partition.

>> Is this something I should be worried about, and how does it come about.  I
>> built a new RAID 5, Logical device, on the card, which the LSI utility says
>> is 1430511MB in size.
>>     
>
> 1430511*1024*2
> 2929686528
>
>   
>> Here's the relevant output from DMESG:
>>
>> scsi 4:1:0:0: Direct-Access     MegaRAID LD 0 RAID5 1430G 815C PQ: 0 ANSI: 2
>> sd 4:1:0:0: [sda] 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)
>> sd 4:1:0:0: [sda] Write Protect is off
>> sd 4:1:0:0: [sda] Mode Sense: 00 00 00 00
>> sd 4:1:0:0: [sda] Asking for cache data failed
>> sd 4:1:0:0: [sda] Assuming drive cache: write through
>> sd 4:1:0:0: [sda] 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)
>> sd 4:1:0:0: [sda] Write Protect is off
>> sd 4:1:0:0: [sda] Mode Sense: 00 00 00 00
>> sd 4:1:0:0: [sda] Asking for cache data failed
>> sd 4:1:0:0: [sda] Assuming drive cache: write through
>> sda: sda1
>> sda: p1 size 2930304132 limited to end of disk
>> sd 4:1:0:0: [sda] Attached SCSI disk
>> sd 4:1:0:0: Attached scsi generic sg1 type 0
>>
>> And /proc/partions:
>>
>> major minor  #blocks  name
>>
>>  3        0   20044080 hda
>>  3        1    9727326 hda1
>>  3        2    9727357 hda2
>>  3        4     586372 hda4
>>  8        0 1464843264 sda
>>  8        1 1464843232 sda1
>> 253        0  314572800 dm-0
>> 253        1  157286400 dm-1
>> 253        2  209715200 dm-2
>> 253        3  104857600 dm-3
>> 253        4  104857600 dm-4
>> 253        5  262144000 dm-5
>>
>>
>> And fdisk:
>>
>> Disk /dev/sda: 1499.9 GB, 1499999502336 bytes
>> 255 heads, 63 sectors/track, 182364 cylinders
>> Units = cylinders of 16065 * 512 = 8225280 bytes
>> Disk identifier: 0x0003d809
>>
>>  Device Boot      Start         End      Blocks   Id  System
>> /dev/sda1               1      182403  1465152066   8e  Linux LVM
>>
>> So, where is the discrepancy creeping in.
>>     
>
> Can you print this using "Units of Blocks" instead of "Cyclinders"?
> Use "-u" parameter.
>   

fdisk -l -u /dev/sda

Disk /dev/sda: 1499.9 GB, 1499999502336 bytes
255 heads, 63 sectors/track, 182364 cylinders, total 2929686528 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x0003d809

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63  2930304194  1465152066   8e  Linux LVM

> hth,
> grant
>
>   
>> Also, I see this in DMESG:
>>
>> sd 4:1:0:0: [sda] Assuming drive cache: write through
>>
>> But, as this card has a battery backup, I have it set to "Write Back" in the
>> configuration.  So, what mode is it really operating in.
>>
>> Cheers,
>> Eddie
>>
>>
>>     
Cheers,
Eddie

Re: Should I be Worried: sda: p1 size .... limited to end of disk

[Eddie]

Eddie wrote:
> The raw partition table entry is:
>
> 00 01 01 00 8E FE FF FF 3F 00 00 00 84 E4 A8 AE
>
> Active Flag = 00
> Starting Head = 01
> Starting Cylinder = 0001
> Partition Type = x'8E' - Linux LVM
> Ending Head = x'FE' - 254
> Ending Cylinder/Sector = x'FFFF' - LBA
> Offset to Start = x'0000003F' - 63
> # of Sectors = x'AEA8E484' - 2930304132 - Hmmmmmmm
>
> So, that looks like the culprit.  Now, how did it happen.  I know I 
> can, sort of safely, rebuild that, by running (c)fdisk and making sure 
> I start the partition at exactly the same point.  But all I did the 
> first time, was use cfdisk, and allocate the complete disk to the 1st 
> primary partition.
OK, I recreated the partition table, trying both fdisk and cfdisk.  I'm 
still not sure how the original had the wrong values in there.  I guess 
that will remain a mystery.


fdisk -l -u /dev/sda

Disk /dev/sda: 1499.9 GB, 1499999502336 bytes
255 heads, 63 sectors/track, 182364 cylinders, total 2929686528 sectors
Units = sectors of 1 * 512 = 512 bytes
Disk identifier: 0x0003d809

   Device Boot      Start         End      Blocks   Id  System
/dev/sda1              63  2929677659  1464838798+  8e  Linux LVM


OK, the total sectors seems to match the hardware scan -> sd 4:1:0:0: 
[sda] 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)

But 255 * 63 * 182364 = 2929677660.  What's this discrepancy due to.  
Does the drive report ALL sectors, even the ones used to replace "bad" ones.

However, 2929677660 does seem to tie up quite nicely with the "end 
sector", from the fdisk, so I'm assuming that everything is now correct.

Well, apart from the fact that LVM reports a Total PE allocation of 
357627 extents, which maps to 1464840192 Blocks, according to my maths 
anyway, which happens to be bigger than the "available" sectors on the 
disk.  I guess it's time to hit the LVM list, to see if there's any way 
I can safely correct this, before anything tries to use the "phantom" 
sectors.

Cheers,
Eddie

Re: Should I be Worried: sda: p1 size .... limited to end of disk

[Grant Grundler]

On Tue, Oct 13, 2009 at 5:48 PM, Eddie <stunnel@attglobal.net> wrote:
....
>  Device Boot      Start         End      Blocks   Id  System
> /dev/sda1              63  2929677659  1464838798+  8e  Linux LVM
>
>
> OK, the total sectors seems to match the hardware scan -> sd 4:1:0:0: [sda]
> 2929686528 512-byte hardware sectors: (1.49 TB/1.36 TiB)
>
> But 255 * 63 * 182364 = 2929677660.  What's this discrepancy due to.  Does
> the drive report ALL sectors, even the ones used to replace "bad" ones.

Definitely does not. SCSI disks report whatever number of sectors the
firmware is told to report. That's *always* less than the actual
number of physical sectors since drives need a reasonable supply of
"spare" sectors/tracks.


> However, 2929677660 does seem to tie up quite nicely with the "end sector",
> from the fdisk, so I'm assuming that everything is now correct.
>
> Well, apart from the fact that LVM reports a Total PE allocation of 357627
> extents, which maps to 1464840192 Blocks, according to my maths anyway,
> which happens to be bigger than the "available" sectors on the disk.  I
> guess it's time to hit the LVM list, to see if there's any way I can safely
> correct this, before anything tries to use the "phantom" sectors.

I expect the LVM needs to be resized anytime the size of the
underlying partitions has changed. I'll bet there wiki/HOWTO someplace
that describes how to do that.

grant

>
> Cheers,
> Eddie
>
>
>
>
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