I'm setting up a new file server using the same storage configuration as my existing server, but the procedure is failing and i cannot figure out why.  my goal is to create a TrueCrypt volume on top of a RAID 10 volume.  however, when i start truecrypt -c, it destroys the RAID volume.  The same procedure worked for my previous server, so i'm not sure what's going on.My procedure:# create a data partition on each disk (/dev/sdb, /dev/sdc, /dev/sdd, /dev/sde):fdisk /dev/sdXnew, p, 1, 4096, 2930273071, type, da, write# combine data partitions into raid10 array:mdadm --create /dev/md0 -v --raid-devices=4 --chunk=512 --level=raid10 --layout=f2 /dev/sdb1 /dev/sdc1 /dev/sdd1 /dev/sde1# create a truecrypt volume on the new data partition /dev/md0:truecrypt -c /dev/md0shortly after truecrypt starts, i get a component failure from mdadm for one or more of the disks:$ cat /proc/mdstat; echo; mdadm --misc --detail /dev/md0 Personalities : [raid10]md0 : active raid10 sdd1[4] sdc1[1] sde1[3] sdb1[0](F)      2930006016 blocks super 1.2 512K chunks 2 far-copies [4/3] [_UUU]unused devices: <none>/dev/md0:        Version : 1.2  Creation Time : Fri Sep 21 14:27:31 2012     Raid Level : raid10     Array Size : 2930006016 (2794.27 GiB 3000.33 GB)  Used Dev Size : 1465003008 (1397.14 GiB 1500.16 GB)   Raid Devices : 4  Total Devices : 4    Persistence : Superblock is persistent    Update Time : Tue Sep 25 10:54:06 2012          State : active, degraded Active Devices : 3Working Devices : 3 Failed Devices : 1  Spare Devices : 0         Layout : far=2     Chunk Size : 512K           Name : emma:0  (local to host emma)           UUID : 21c2f9b7:923dacab:805375f8:96a2959b         Events : 33268    Number   Major   Minor   RaidDevice State       0       0        0        0      removed       1       8       33        1      active sync   /dev/sdc1       4       8       49        2      active sync   /dev/sdd1       3       8       65        3      active sync   /dev/sde1       0       8       17        -      faulty spare   /dev/sdb1and dmesg gives those error messages:[326876.652057] ata3.00: status: { DRDY ERR }[326876.652801] ata3.00: error: { ABRT }[326876.653543] ata3.00: failed command: WRITE FPDMA QUEUED[326876.654301] ata3.00: cmd 61/80:f0:80:f6:58/00:00:57:00:00/40 tag 30 ncq 65536 out[326876.654301]          res 41/04:00:00:00:00/04:00:00:00:00/00 Emask 0x1 (device error)[326876.655812] ata3.00: status: { DRDY ERR }[326876.656563] ata3.00: error: { ABRT }[326876.657326] ata3: hard resetting link[326876.657328] ata3: nv: skipping hardreset on occupied port[326877.124117] ata3: SATA link up 3.0 Gbps (SStatus 123 SControl 300)[326877.138346] ata3.00: configured for UDMA/133[326877.138397] sd 2:0:0:0: [sdb][326877.138399] Result: hostbyte=0x00 driverbyte=0x08[326877.138402] sd 2:0:0:0: [sdb][326877.138404] Sense Key : 0xb [current] [descriptor][326877.138408] Descriptor sense data with sense descriptors (in hex):[326877.138411]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00[326877.138423]         00 00 00 00[326877.138428] sd 2:0:0:0: [sdb][326877.138430] ASC=0x0 ASCQ=0x0[326877.138434] sd 2:0:0:0: [sdb] CDB:[326877.138435] cdb[0]=0x2a: 2a 00 57 58 f0 80 00 00 80 00[326877.138446] end_request: I/O error, dev sdb, sector 1465446528[326877.138844] sd 2:0:0:0: [sdb][326877.138846] Result: hostbyte=0x00 driverbyte=0x08[326877.138847] sd 2:0:0:0: [sdb][326877.138849] Sense Key : 0xb [current] [descriptor][326877.138851] Descriptor sense data with sense descriptors (in hex):[326877.138852]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00[326877.138860]         00 00 00 00[326877.138864] sd 2:0:0:0: [sdb][326877.138865] ASC=0x0 ASCQ=0x0[326877.138867] sd 2:0:0:0: [sdb] CDB:[326877.138868] cdb[0]=0x2a: 2a 00 57 58 f1 00 00 00 80 00[326877.138875] end_request: I/O error, dev sdb, sector 1465446656[326877.139208] sd 2:0:0:0: [sdb][326877.139210] Result: hostbyte=0x00 driverbyte=0x08[326877.139212] sd 2:0:0:0: [sdb][326877.139213] Sense Key : 0xb [current] [descriptor][326877.139215] Descriptor sense data with sense descriptors (in hex):[326877.139217]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00[326877.139224]         00 00 00 00...[326877.155726] sd 2:0:0:0: [sdb][326877.155727] ASC=0x0 ASCQ=0x0[326877.155729] sd 2:0:0:0: [sdb] CDB:[326877.155730] cdb[0]=0x2a: 2a 00 57 58 f6 80 00 00 80 00[326877.155736] end_request: I/O error, dev sdb, sector 1465448064[326877.155987] ata3: EH complete[326877.281684] md/raid10:md0: Disk failure on sdb1, disabling device.[326877.281684] md/raid10:md0: Operation continuing on 3 devices.[326877.801033] RAID10 conf printout:[326877.801038]  --- wd:3 rd:4[326877.801040]  disk 0, wo:1, o:0, dev:sdb1[326877.801042]  disk 1, wo:0, o:1, dev:sdc1[326877.801044]  disk 2, wo:0, o:1, dev:sdd1[326877.801046]  disk 3, wo:0, o:1, dev:sde1[326877.801071] RAID10 conf printout:[326877.801074]  --- wd:3 rd:4[326877.801076]  disk 1, wo:0, o:1, dev:sdc1[326877.801078]  disk 2, wo:0, o:1, dev:sdd1[326877.801079]  disk 3, wo:0, o:1, dev:sde1[326899.233166] ata4: EH in SWNCQ mode,QC:qc_active 0x7 sactive 0x7[326899.233384] ata4: SWNCQ:qc_active 0x1 defer_bits 0x6 last_issue_tag 0x0[326899.233384]   dhfis 0x1 dmafis 0x0 sdbfis 0x0[326899.233643] ata4: ATA_REG 0x41 ERR_REG 0x4[326899.233775] ata4: tag : dhfis dmafis sdbfis sactive[326899.234078] ata4: tag 0x0: 1 0 0 1[326899.234458] ata4.00: exception Emask 0x1 SAct 0x7 SErr 0x0 action 0x6 frozen[326899.234843] ata4.00: Ata error. fis:0x41[326899.235230] ata4.00: failed command: WRITE FPDMA QUEUED[326899.235617] ata4.00: cmd 61/80:00:80:e0:5b/00:00:57:00:00/40 tag 0 ncq 65536 out[326899.235617]          res 41/04:00:00:00:00/04:00:00:00:00/00 Emask 0x1 (device error)[326899.236423] ata4.00: status: { DRDY ERR }[326899.236818] ata4.00: error: { ABRT }[326899.237200] ata4.00: failed command: WRITE FPDMA QUEUED[326899.237609] ata4.00: cmd 61/80:08:00:e1:5b/00:00:57:00:00/40 tag 1 ncq 65536 out[326899.237609]          res 41/04:00:00:00:00/04:00:00:00:00/00 Emask 0x1 (device error)[326899.238428] ata4.00: status: { DRDY ERR }[326899.238865] ata4.00: error: { ABRT }[326899.239288] ata4.00: failed command: WRITE FPDMA QUEUED[326899.239730] ata4.00: cmd 61/80:10:80:e1:5b/00:00:57:00:00/40 tag 2 ncq 65536 out[326899.239730]          res 41/04:00:00:00:00/04:00:00:00:00/00 Emask 0x1 (device error)[326899.240682] ata4.00: status: { DRDY ERR }[326899.241162] ata4.00: error: { ABRT }[326899.241653] ata4: hard resetting link[326899.241654] ata4: nv: skipping hardreset on occupied port[326899.760685] ata4: SATA link up 3.0 Gbps (SStatus 123 SControl 300)[326899.774644] ata4.00: configured for UDMA/133[326899.774695] sd 3:0:0:0: [sdc][326899.774698] Result: hostbyte=0x00 driverbyte=0x08[326899.774700] sd 3:0:0:0: [sdc][326899.774702] Sense Key : 0xb [current] [descriptor][326899.774707] Descriptor sense data with sense descriptors (in hex):[326899.774709]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00[326899.774721]         00 00 00 00[326899.774727] sd 3:0:0:0: [sdc][326899.774728] ASC=0x0 ASCQ=0x0[326899.774732] sd 3:0:0:0: [sdc] CDB:[326899.774734] cdb[0]=0x2a: 2a 00 57 5b e0 80 00 00 80 00[326899.774744] end_request: I/O error, dev sdc, sector 1465639040[326899.775097] sd 3:0:0:0: [sdc][326899.775098] Result: hostbyte=0x00 driverbyte=0x08[326899.775100] sd 3:0:0:0: [sdc][326899.775102] Sense Key : 0xb [current] [descriptor][326899.775104] Descriptor sense data with sense descriptors (in hex):[326899.775105]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00[326899.775113]         00 00 00 00[326899.775117] sd 3:0:0:0: [sdc][326899.775118] ASC=0x0 ASCQ=0x0[326899.775120] sd 3:0:0:0: [sdc] CDB:[326899.775121] cdb[0]=0x2a: 2a 00 57 5b e1 00 00 00 80 00[326899.775128] end_request: I/O error, dev sdc, sector 1465639168[326899.775404] sd 3:0:0:0: [sdc][326899.775405] Result: hostbyte=0x00 driverbyte=0x08[326899.775407] sd 3:0:0:0: [sdc][326899.775408] Sense Key : 0xb [current] [descriptor][326899.775410] Descriptor sense data with sense descriptors (in hex):[326899.775412]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00[326899.775412]         72 0b 00 00 00 00 00 0c 00 0a 80 00 00 00 00 00[326899.775420]         00 00 00 00[326899.775423] sd 3:0:0:0: [sdc][326899.775424] ASC=0x0 ASCQ=0x0[326899.775427] sd 3:0:0:0: [sdc] CDB:[326899.775428] cdb[0]=0x2a: 2a 00 57 5b e1 80 00 00 80 00[326899.775434] end_request: I/O error, dev sdc, sector 1465639296[326899.775691] ata4: EH complete[326899.830768] Buffer I/O error on device md0p1, logical block 1474688[326899.830965] lost page write due to I/O error on md0p1[326899.831257] Buffer I/O error on device md0p1, logical block 1474689[326899.831419] lost page write due to I/O error on md0p1[326899.831424] Buffer I/O error on device md0p1, logical block 1474690[326899.831585] lost page write due to I/O error on md0p1[326899.831589] Buffer I/O error on device md0p1, logical block 1474691[326899.831751] lost page write due to I/O error on md0p1This isn't an actual disk failure because a) smartd doesn't see any issues with the disks and b) I can create a full TrueCrypt volume on each of the disks individually.I also tried creating a partition on /dev/md0 (both 83/Linux and da/Non-FS data) and then creating a TrueCrypt volume on the partition /dev/md0p1 (where this dmesg output came from), but this does not work either.I'm assuming TrueCrypt is somehow destroying mdadm-important meta data.  But what's weird is that this exact procedure has worked fine before.  What's going on here?[root@emma]# uname -aLinux emma 3.5.4-1-ARCH #1 SMP PREEMPT Sat Sep 15 08:12:04 CEST 2012 x86_64 GNU/Linux[root@emma]# mdadm --versionmdadm - v3.2.5 - 18th May 2012[root@emma]# truecrypt --versionTrueCrypt 7.1a[root@emma]# fdisk -lDisk /dev/sda: 160.0 GB, 160040803840 bytes255 heads, 63 sectors/track, 19457 cylinders, total 312579695 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0xe256e256   Device Boot      Start         End      Blocks   Id  System/dev/sda1   *          63      208844      104391   83  Linux/dev/sda2          208845      738989      265072+  82  Linux swap / Solaris/dev/sda3          738990    62187614    30724312+  83  Linux/dev/sda4        62187615   312579694   125196040   83  LinuxDisk /dev/sdb: 1500.3 GB, 1500301910016 bytes16 heads, 62 sectors/track, 2953908 cylinders, total 2930277168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 4096 bytesI/O size (minimum/optimal): 4096 bytes / 4096 bytesDisk identifier: 0xcbb904fc   Device Boot      Start         End      Blocks   Id  System/dev/sdb1            4096  2930273071  1465134488   da  Non-FS dataDisk /dev/sdc: 1500.3 GB, 1500301910016 bytes16 heads, 62 sectors/track, 2953908 cylinders, total 2930277168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x6978c214   Device Boot      Start         End      Blocks   Id  System/dev/sdc1            4096  2930273071  1465134488   da  Non-FS dataDisk /dev/sdd: 1500.3 GB, 1500301910016 bytes16 heads, 62 sectors/track, 2953908 cylinders, total 2930277168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x8dd1e314   Device Boot      Start         End      Blocks   Id  System/dev/sdd1            4096  2930273071  1465134488   da  Non-FS dataDisk /dev/sde: 1500.3 GB, 1500301910016 bytes16 heads, 62 sectors/track, 2953908 cylinders, total 2930277168 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 512 bytesI/O size (minimum/optimal): 512 bytes / 512 bytesDisk identifier: 0x70b7ece7   Device Boot      Start         End      Blocks   Id  System/dev/sde1            4096  2930273071  1465134488   da  Non-FS dataDisk /dev/md0: 3000.3 GB, 3000326160384 bytes2 heads, 3 sectors/track, 976668672 cylinders, total 5860012032 sectorsUnits = sectors of 1 * 512 = 512 bytesSector size (logical/physical): 512 bytes / 4096 bytesI/O size (minimum/optimal): 524288 bytes / 2097152 bytesDisk identifier: 0xce6d6f88    Device Boot      Start         End      Blocks   Id  System/dev/md0p1            4096  4294967294  2147481599+  83  LinuxEDIT: when this procedure worked, it was probably using TrueCrypt 6 -- I'm going to give it a try with 6 to see what happens.  I'll update with the results...
TrueCrypt is destoying mdadm volume
arch linux;mdadm;truecrypt
Those error messages really read like disk errors, not metadata corruption. They are coming from libata, not mdraid.They may not be problems with the actual disk though. For example, could be a SATA driver bug, defective SATA controller, bad connector, bad cable, etc.You may only see it when creating over the mdraid array because of different I/O patterns. But I'm pretty confident that even if you get something else to work, it won't be stable, because you actually have flaky drivers or hardware.BTW: What does smartctl -x or smartctl -a say? Does it have a SATA errors counter?