"fake" RAID 0 or RAID10, dmraid -tay reports incorrect size

[Martina N.]

Follow-up on:

https://askubuntu.com/questions/113561/how-to-modify-fix-incorrectly-detected-dmraid-fakeraid-raid-10-array

I am not certain that dmraid is the cause of this error but it may be the best place to start looking for it.

This issue was raised on askubuntu 7 years ago without a meaninful reaction - therefore i do not want to rely on escalation from there.

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(live CD)

Description: Ubuntu 18.04.2 LTS
Release: 18.04
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dmraid:
  Installed: 1.0.0.rc16-8ubuntu1
  Candidate: 1.0.0.rc16-8ubuntu1
  Version table:
 *** 1.0.0.rc16-8ubuntu1 500
        500 http://archive.ubuntu.com/ubuntu bionic/main amd64 Packages
        100 /var/lib/dpkg/status
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expected to see my RAID 10 in the system
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RAID10 was not detected automaticaly, instead, the 4 individual drives are displayed in GParted.
Attempted to add the RAID manually (dmraid -ay), dmraid recognises there is a raid, but reports incorrect size and checksum error

Reconfigured RAID to RAID0 and RAID1 to test, both RAID found automatically, RAID0 has incorrect size, checksum correct in both cases

*************
sdb,sdc : Seagate 2TB
sdd,sde : Toshiba 2TB

3907029168 sectors each HDD
*************

#dmraid -tay

pdc_bagjfgcja: 0 3518828800 striped 2 128 /dev/sdb 0 /dev/sdc 0
pdc_bffcfgdcc: 0 3906898048 mirror core 2 131072 nosync 2 /dev/sdd 0 /dev/sde 0 1 handle_errors

*************

#dmraid -s

*** Active Set
name : pdc_bagjfgcja
size : 3518828800
stride : 128
type : stripe
status : ok
subsets: 0
devs : 2
spares : 0
*** Active Set
name : pdc_bffcfgdcc
size : 3906898048
stride : 128
type : mirror
status : ok
subsets: 0
devs : 2
spares : 0

--------------
#dmraid -n /dev/sdb

/dev/sdb (pdc):
0x000 promise_id: "Promise Technology, Inc."
0x018 unknown_0: 0x20000 131072
0x01c magic_0: 0xe1e2e3e4
0x020 unknown_1: 0xdddedfe0 3722371040
0x024 magic_1: 0xd9dadbdc
0x028 unknown_2: 0xd7d8 55256
0x200 raid.flags: 0xfdfeffc0
0x204 raid.unknown_0: 0x7 7
0x205 raid.disk_number: 0
0x206 raid.channel: 0
0x207 raid.device: 0
0x208 raid.magic_0: 0xcd0602
0x20c raid.unknown_1: 0x0 0
0x210 raid.start: 0x0 0
0x214 raid.disk_secs: 3906898096
0x218 raid.unknown_3: 0xffffffff 4294967295
0x21c raid.unknown_4: 0x1 1
0x21e raid.status: 0xf
0x21f raid.type: 0x0
0x220 raid.total_disks: 2
0x221 raid.raid0_shift: 7
0x222 raid.raid0_disks: 2
0x223 raid.array_number: 0
0x224 raid.total_secs: 3518828800
0x228 raid.cylinders: 65534
0x22a raid.heads: 254
0x22b raid.sectors: 63
0x22c raid.magic_1: 0x6600602
0x230 raid.unknown_5: 0x0 0
0x234 raid.disk[0].unknown_0: 0x7
0x236 raid.disk[0].channel: 0
0x237 raid.disk[0].device: 0
0x238 raid.disk[0].magic_0: 0xcd0602
0x23c raid.disk[0].disk_number: 0
0x240 raid.disk[1].unknown_0: 0x207
0x242 raid.disk[1].channel: 1
0x243 raid.disk[1].device: 0
0x244 raid.disk[1].magic_0: 0xce0602
0x248 raid.disk[1].disk_number: 65536
0x7fc checksum: 0x87c487f9 Ok

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3518828800 is 2*3906898048 with the most significant of the 33 bits ignored.

Hence the assumption that a 32 bit integer is used for the number of sectors somewhere.

Thank you for looking into this.

Regards,
Martina.

ProblemType: Bug
DistroRelease: Ubuntu 18.04
Package: dmraid 1.0.0.rc16-8ubuntu1
ProcVersionSignature: Ubuntu 4.18.0-15.16~18.04.1-generic 4.18.20
Uname: Linux 4.18.0-15-generic x86_64
ApportVersion: 2.20.9-0ubuntu7.5
Architecture: amd64
CasperVersion: 1.394
Date: Sun Jun 2 19:38:05 2019
LiveMediaBuild: Ubuntu 18.04.2 LTS "Bionic Beaver" - Release amd64 (20190210)
ProcEnviron:
 TERM=xterm-256color
 PATH=(custom, no user)
 LANG=en_US.UTF-8
 SHELL=/bin/bash
SourcePackage: dmraid
UpgradeStatus: No upgrade log present (probably fresh install)