* 1T and 500+500 mirror, but different speeds
@ 2021-07-09 12:27 David T-G
2021-07-09 16:39 ` Wols Lists
0 siblings, 1 reply; 4+ messages in thread
From: David T-G @ 2021-07-09 12:27 UTC (permalink / raw)
To: Linux RAID list
Hi, all --
I have a 1T drive
jpo:~ # parted /dev/sdb print
Model: ATA ST31000524AS (scsi)
Disk /dev/sdb: 1000GB
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
1 1049kB 1000GB 1000GB primary ntfs type=07
jpo:~ # smartctl -i /dev/sdb
smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.78-default] (SUSE RPM)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Seagate Barracuda 7200.12
Device Model: ST31000524AS
Serial Number: 9VPG4SHD
LU WWN Device Id: 5 000c50 04d20d244
Firmware Version: JC45
User Capacity: 1,000,204,886,016 bytes [1.00 TB]
Sector Size: 512 bytes logical/physical
Rotation Rate: 7200 rpm
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Thu Jul 8 11:32:27 2021 UTC
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
and also two 500G drives
jpo:~ # parted /dev/sdc print
Model: ATA WDC WD5000AAVS-0 (scsi)
Disk /dev/sdc: 500GB
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 356GB 356GB ata-WDC_WD5000AAVS-00ZTB0_WD-WMASU06 raid
2 356GB 495GB 139GB raid
4 495GB 500GB 5001MB reiserfs wwn-0x50014ee055b724ad
jpo:~ # smartctl -i /dev/sdc
smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.78-default] (SUSE RPM)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Western Digital Caviar Green
Device Model: WDC WD5000AAVS-00ZTB0
Serial Number: WD-WMASU0686160
LU WWN Device Id: 5 0014ee 055b724ad
Firmware Version: 01.01B01
User Capacity: 500,107,862,016 bytes [500 GB]
Sector Size: 512 bytes logical/physical
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS (minor revision not indicated)
SATA Version is: SATA 2.5, 3.0 Gb/s
Local Time is: Thu Jul 8 11:32:35 2021 UTC
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
that I plan to stripe together to use to protect the first. The Caviars
are listed as variable speed, but in practice they apparently are just
5400 rpm, so I'd like to take advantage of striping to make them as fast
as possible. This isn't the black magic ;-) of RAID10-on-two-drives,
so I don't have to think of one as "front" and one as "back", but do I
want more than one partition on each to stripe 4 or 6 slices to avoid
hammering on one, or do I just go with each device as a whole and let
mdadm handle the magic for me?
I also plan to use a partition on the 1T drive, but once I have the
striped metadevice do I particularly want or particlularly not want to
slice a partition out of it? I figured I would partition since that
would let me exactly match the mirror halves to each other.
Oh, and to make this more fun the two 500s are actually part of a 3-dev
RAID5 set holding the data to migrate to the 1T to then mirror, so I
don't get to destructively play with this a dozen times :-)
Thanks in advance & have a great day!
:-D
--
David T-G
See http://justpickone.org/davidtg/email/
See http://justpickone.org/davidtg/tofu.txt
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: 1T and 500+500 mirror, but different speeds
2021-07-09 12:27 1T and 500+500 mirror, but different speeds David T-G
@ 2021-07-09 16:39 ` Wols Lists
2021-07-11 3:12 ` David T-G
0 siblings, 1 reply; 4+ messages in thread
From: Wols Lists @ 2021-07-09 16:39 UTC (permalink / raw)
To: David T-G, Linux RAID list
On 09/07/21 13:27, David T-G wrote:
> Hi, all --
>
> I have a 1T drive
>
> jpo:~ # parted /dev/sdb print
> Model: ATA ST31000524AS (scsi)
> Disk /dev/sdb: 1000GB
> Sector size (logical/physical): 512B/512B
> Partition Table: msdos
> Disk Flags:
>
> Number Start End Size Type File system Flags
> 1 1049kB 1000GB 1000GB primary ntfs type=07
>
> jpo:~ # smartctl -i /dev/sdb
> smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.78-default] (SUSE RPM)
> Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
>
> === START OF INFORMATION SECTION ===
> Model Family: Seagate Barracuda 7200.12
Barracuda ... DO NOT USE THIS IN A PARITY RAID ARRAY !!!
Mirroring as you plan here is okay.
> Device Model: ST31000524AS
> Serial Number: 9VPG4SHD
> LU WWN Device Id: 5 000c50 04d20d244
> Firmware Version: JC45
> User Capacity: 1,000,204,886,016 bytes [1.00 TB]
> Sector Size: 512 bytes logical/physical
> Rotation Rate: 7200 rpm
> Device is: In smartctl database [for details use: -P show]
> ATA Version is: ATA8-ACS T13/1699-D revision 4
> SATA Version is: SATA 3.0, 6.0 Gb/s (current: 6.0 Gb/s)
> Local Time is: Thu Jul 8 11:32:27 2021 UTC
> SMART support is: Available - device has SMART capability.
> SMART support is: Enabled
>
> and also two 500G drives
>
> jpo:~ # parted /dev/sdc print
> Model: ATA WDC WD5000AAVS-0 (scsi)
> Disk /dev/sdc: 500GB
> Sector size (logical/physical): 512B/512B
> Partition Table: gpt
> Disk Flags:
>
> Number Start End Size File system Name Flags
> 1 1049kB 356GB 356GB ata-WDC_WD5000AAVS-00ZTB0_WD-WMASU06 raid
> 2 356GB 495GB 139GB raid
> 4 495GB 500GB 5001MB reiserfs wwn-0x50014ee055b724ad
>
> jpo:~ # smartctl -i /dev/sdc
> smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.78-default] (SUSE RPM)
> Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
>
> === START OF INFORMATION SECTION ===
> Model Family: Western Digital Caviar Green
> Device Model: WDC WD5000AAVS-00ZTB0
> Serial Number: WD-WMASU0686160
> LU WWN Device Id: 5 0014ee 055b724ad
> Firmware Version: 01.01B01
> User Capacity: 500,107,862,016 bytes [500 GB]
> Sector Size: 512 bytes logical/physical
> Device is: In smartctl database [for details use: -P show]
> ATA Version is: ATA8-ACS (minor revision not indicated)
> SATA Version is: SATA 2.5, 3.0 Gb/s
> Local Time is: Thu Jul 8 11:32:35 2021 UTC
> SMART support is: Available - device has SMART capability.
> SMART support is: Enabled
>
> that I plan to stripe together to use to protect the first. The Caviars
> are listed as variable speed, but in practice they apparently are just
> 5400 rpm, so I'd like to take advantage of striping to make them as fast
> as possible.
Caviar Green ??? Caviars should be okay, but the "green" moniker makes
me nervous. Check SCT/ERC, but striping/mirroring will be fine.
> This isn't the black magic ;-) of RAID10-on-two-drives,
> so I don't have to think of one as "front" and one as "back", but do I
> want more than one partition on each to stripe 4 or 6 slices to avoid
> hammering on one, or do I just go with each device as a whole and let
> mdadm handle the magic for me?
>
> I also plan to use a partition on the 1T drive, but once I have the
> striped metadevice do I particularly want or particlularly not want to
> slice a partition out of it? I figured I would partition since that
> would let me exactly match the mirror halves to each other.
>
> Oh, and to make this more fun the two 500s are actually part of a 3-dev
> RAID5 set holding the data to migrate to the 1T to then mirror, so I
> don't get to destructively play with this a dozen times :-)
>
Okay, the simple approach.
Create a single-device mirror using the 1TB and the special device
"missing". Copy everything across and make sure it's all okay. (I'm
assuming you can safely wipe this drive as it has nothing on it you wish
to keep.)
Create a striped device using the two 500GB drives.
Add the striped device to the 1TB mirror.
Plan to replace all the disks with something like Seagate Ironwolves or
Toshiba N300s in the near future :-)
https://raid.wiki.kernel.org/index.php/Linux_Raid
Read especially the page on timeout mismatch as this DOES apply to your
Barracuda !!!
Cheers,
Wol
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: 1T and 500+500 mirror, but different speeds
2021-07-09 16:39 ` Wols Lists
@ 2021-07-11 3:12 ` David T-G
2021-07-11 4:09 ` Wols Lists
0 siblings, 1 reply; 4+ messages in thread
From: David T-G @ 2021-07-11 3:12 UTC (permalink / raw)
To: Linux RAID list
Wol, et al --
...and then Wols Lists said...
%
% On 09/07/21 13:27, David T-G wrote:
% > Hi, all --
% >
% > I have a 1T drive
% >
% > jpo:~ # parted /dev/sdb print
% > Model: ATA ST31000524AS (scsi)
...
% > jpo:~ # smartctl -i /dev/sdb
...
% > Model Family: Seagate Barracuda 7200.12
%
% Barracuda ... DO NOT USE THIS IN A PARITY RAID ARRAY !!!
I am aware of the general problem, and I run the handy timeout script
# set the timeouts on the local drives
printf "${CBLU}Drive timeouts${CBLK}: "
for DISK in sda sdb sdc sdd sde sdf sdg sdh # a-d on mobo ; e-h on card
do
printf "$DISK "
smartctl -q errorsonly -l scterc,70,70 /dev/$DISK
if [ 4 -eq $? ]
then
echo 180 > /sys/block/$DISK/device/timeout
printf "${CYLO}180"
else
printf "${CGRN}Y"
fi
printf "${CBLK} ; "
done
echo ''
to reset as needed, and I even have no plans to parity this drive, but I
didn't realize that it was a problem disk! Thanks for the heads-up.
%
% Mirroring as you plan here is okay.
That's good. Of course, that then makes me scratch my head a bit since
it's still paired with other and needs to not blow up ... I'll have to
back and read more to see why mirror is safe.
%
...
% > and also two 500G drives
% >
% > jpo:~ # parted /dev/sdc print
% > Model: ATA WDC WD5000AAVS-0 (scsi)
...
% > jpo:~ # smartctl -i /dev/sdc
...
% > Model Family: Western Digital Caviar Green
...
% > that I plan to stripe together to use to protect the first. The Caviars
% > are listed as variable speed, but in practice they apparently are just
% > 5400 rpm, so I'd like to take advantage of striping to make them as fast
% > as possible.
%
% Caviar Green ??? Caviars should be okay, but the "green" moniker makes
Yeah, I'm not too happy about that ... Supposedly they will vary speed
based on demand, so they can deliver 7200rpm performance, but apparently
they always stay at 5400rpm and so they're just basic drives. Meh.
% me nervous. Check SCT/ERC, but striping/mirroring will be fine.
More of that confusion stuff :-) but happy.
%
% > This isn't the black magic ;-) of RAID10-on-two-drives,
% > so I don't have to think of one as "front" and one as "back", but do I
% > want more than one partition on each to stripe 4 or 6 slices to avoid
% > hammering on one, or do I just go with each device as a whole and let
% > mdadm handle the magic for me?
% >
...
% Okay, the simple approach.
%
% Create a single-device mirror using the 1TB and the special device
% "missing". Copy everything across and make sure it's all okay. (I'm
% assuming you can safely wipe this drive as it has nothing on it you wish
% to keep.)
Correct.
%
% Create a striped device using the two 500GB drives.
That's the fun part ... I'm thinkin' I'm just going to have to do sector
math to predict how large the new dev can be so that I can back into a
proper partition size on the 1T so that both halves can match.
How much overhead does md need for striping (RAID0)? Given these two
jpo:~ # parted /dev/sdc unit s print free
Model: ATA WDC WD5000AAVS-0 (scsi)
Disk /dev/sdc: 976773168s
Sector size (logical/physical): 512B/512B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
34s 2047s 2014s Free Space
1 2048s 696250367s 696248320s ata-WDC_WD5000AAVS-00ZTB0_WD-WMASU06 raid
2 696250368s 967006207s 270755840s raid
4 967006208s 976773119s 9766912s reiserfs wwn-0x50014ee055b724ad
976773120s 976773134s 15s Free Space
500G disks (976773100 total sectors each, right?), how large a partition
can I create on this
jpo:~ # parted /dev/sdb unit s print free
Model: ATA ST31000524AS (scsi)
Disk /dev/sdb: 1953525168s
Sector size (logical/physical): 512B/512B
Partition Table: msdos
Disk Flags:
Number Start End Size Type File system Flags
63s 2047s 1985s Free Space
1 2048s 1953521663s 1953519616s primary ntfs type=07
1953521664s 1953525167s 3504s Free Space
1T disk (1953525104 sectors, which is 21096 less than the 2ea others
together) can I create and expect to be able to match it across the pair?
Is this something I could mock up with overlays without destroying the
existing data?
%
% Add the striped device to the 1TB mirror.
At that point it becomes easy :-)
%
% Plan to replace all the disks with something like Seagate Ironwolves or
% Toshiba N300s in the near future :-)
Actually, I have four Seagate 4T drives
diskfarm:~ # parted /dev/sdd print
Model: ATA ST4000DM000-1F21 (scsi)
Disk /dev/sdd: 4001GB
Sector size (logical/physical): 512B/4096B
Partition Table: gpt
Disk Flags:
Number Start End Size File system Name Flags
1 1049kB 4001GB 4001GB xfs ata-ST4000DM000-1F2168_W300EYNA raid
2 4001GB 4001GB 134MB reiserfs wwn-0x5000c50069a8d76f
diskfarm:~ # smartctl -i /dev/sdd
smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
=== START OF INFORMATION SECTION ===
Model Family: Seagate Desktop HDD.15
Device Model: ST4000DM000-1F2168
Serial Number: W300EYNA
LU WWN Device Id: 5 000c50 069a8d76f
Firmware Version: CC52
User Capacity: 4,000,787,030,016 bytes [4.00 TB]
Sector Sizes: 512 bytes logical, 4096 bytes physical
Rotation Rate: 5900 rpm
Form Factor: 3.5 inches
Device is: In smartctl database [for details use: -P show]
ATA Version is: ATA8-ACS T13/1699-D revision 4
SATA Version is: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
Local Time is: Sat Jul 10 21:38:12 2021 UTC
SMART support is: Available - device has SMART capability.
SMART support is: Enabled
in another machine that I plan to upgrade to larger disks and hand down
to this one. They're older, and they don't
diskfarm:~ # smartctl -l scterc /dev/sdd
smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM)
Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
SCT Error Recovery Control command not supported
have SMART error handling, but at least they aren't SMR :-)
%
% https://raid.wiki.kernel.org/index.php/Linux_Raid
%
% Read especially the page on timeout mismatch as this DOES apply to your
% Barracuda !!!
I'll go back again :-)
%
% Cheers,
% Wol
Have a great weekend!
:-D
--
David T-G
See http://justpickone.org/davidtg/email/
See http://justpickone.org/davidtg/tofu.txt
^ permalink raw reply [flat|nested] 4+ messages in thread
* Re: 1T and 500+500 mirror, but different speeds
2021-07-11 3:12 ` David T-G
@ 2021-07-11 4:09 ` Wols Lists
0 siblings, 0 replies; 4+ messages in thread
From: Wols Lists @ 2021-07-11 4:09 UTC (permalink / raw)
To: David T-G, Linux RAID list
On 11/07/21 04:12, David T-G wrote:
> Wol, et al --
>
> ...and then Wols Lists said...
> %
>
>
> %
> % Mirroring as you plan here is okay.
>
> That's good. Of course, that then makes me scratch my head a bit since
> it's still paired with other and needs to not blow up ... I'll have to
> back and read more to see why mirror is safe.
>
Mirroring is safe because, whatever happens to the mirror, you only need
one disk to recover. So if the raid falls apart your data is not in danger.
>
> %
> ...
> % > and also two 500G drives
> % >
> % > jpo:~ # parted /dev/sdc print
> % > Model: ATA WDC WD5000AAVS-0 (scsi)
> ...
> % > jpo:~ # smartctl -i /dev/sdc
> ...
> % > Model Family: Western Digital Caviar Green
> ...
> % > that I plan to stripe together to use to protect the first. The Caviars
> % > are listed as variable speed, but in practice they apparently are just
> % > 5400 rpm, so I'd like to take advantage of striping to make them as fast
> % > as possible.
> %
> % Caviar Green ??? Caviars should be okay, but the "green" moniker makes
>
> Yeah, I'm not too happy about that ... Supposedly they will vary speed
> based on demand, so they can deliver 7200rpm performance, but apparently
> they always stay at 5400rpm and so they're just basic drives. Meh.
>
>
> % me nervous. Check SCT/ERC, but striping/mirroring will be fine.
>
> More of that confusion stuff :-) but happy.
>
>
> %
> % > This isn't the black magic ;-) of RAID10-on-two-drives,
> % > so I don't have to think of one as "front" and one as "back", but do I
> % > want more than one partition on each to stripe 4 or 6 slices to avoid
> % > hammering on one, or do I just go with each device as a whole and let
> % > mdadm handle the magic for me?
> % >
> ...
> % Okay, the simple approach.
> %
> % Create a single-device mirror using the 1TB and the special device
> % "missing". Copy everything across and make sure it's all okay. (I'm
> % assuming you can safely wipe this drive as it has nothing on it you wish
> % to keep.)
>
> Correct.
>
>
> %
> % Create a striped device using the two 500GB drives.
>
> That's the fun part ... I'm thinkin' I'm just going to have to do sector
> math to predict how large the new dev can be so that I can back into a
> proper partition size on the 1T so that both halves can match.
Do you need the entire space? Can you create a 900GB mirror on the 1TB?
You can always grow the mirror and the filesystem later.
>
>
> %
> % Plan to replace all the disks with something like Seagate Ironwolves or
> % Toshiba N300s in the near future :-)
>
> Actually, I have four Seagate 4T drives
>
> diskfarm:~ # parted /dev/sdd print
> Model: ATA ST4000DM000-1F21 (scsi)
> Disk /dev/sdd: 4001GB
> Sector size (logical/physical): 512B/4096B
> Partition Table: gpt
> Disk Flags:
>
> Number Start End Size File system Name Flags
> 1 1049kB 4001GB 4001GB xfs ata-ST4000DM000-1F2168_W300EYNA raid
> 2 4001GB 4001GB 134MB reiserfs wwn-0x5000c50069a8d76f
>
> diskfarm:~ # smartctl -i /dev/sdd
> smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM)
> Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
>
> === START OF INFORMATION SECTION ===
> Model Family: Seagate Desktop HDD.15
> Device Model: ST4000DM000-1F2168
> Serial Number: W300EYNA
> LU WWN Device Id: 5 000c50 069a8d76f
> Firmware Version: CC52
> User Capacity: 4,000,787,030,016 bytes [4.00 TB]
> Sector Sizes: 512 bytes logical, 4096 bytes physical
> Rotation Rate: 5900 rpm
> Form Factor: 3.5 inches
> Device is: In smartctl database [for details use: -P show]
> ATA Version is: ATA8-ACS T13/1699-D revision 4
> SATA Version is: SATA 3.1, 6.0 Gb/s (current: 6.0 Gb/s)
> Local Time is: Sat Jul 10 21:38:12 2021 UTC
> SMART support is: Available - device has SMART capability.
> SMART support is: Enabled
>
> in another machine that I plan to upgrade to larger disks and hand down
> to this one. They're older, and they don't
>
> diskfarm:~ # smartctl -l scterc /dev/sdd
> smartctl 7.0 2019-05-21 r4917 [x86_64-linux-5.3.18-lp152.63-default] (SUSE RPM)
> Copyright (C) 2002-18, Bruce Allen, Christian Franke, www.smartmontools.org
>
> SCT Error Recovery Control command not supported
>
> have SMART error handling, but at least they aren't SMR :-)
>
They're no better! "SCT Error Recovery Control command not supported".
This is the red flag. This is the same problem as with the Barracudas.
>
> %
> % https://raid.wiki.kernel.org/index.php/Linux_Raid
> %
> % Read especially the page on timeout mismatch as this DOES apply to your
> % Barracuda !!!
>
> I'll go back again :-)
>
And it applies to your 4TBs as well. I wouldn't worry too much - I'm
running a mirror on two 3TB Barracudas (I wouldn't have bought them if
I'd realised, but I was a raid newbie back then ...)
Cheers,
Wol
^ permalink raw reply [flat|nested] 4+ messages in thread
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2021-07-09 12:27 1T and 500+500 mirror, but different speeds David T-G
2021-07-09 16:39 ` Wols Lists
2021-07-11 3:12 ` David T-G
2021-07-11 4:09 ` Wols Lists
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