| ccd.4 (3f4f4a1465e1b9e6174d6bac813020768efd18b3) | ccd.4 (d5bd01d2136ab3597c686edfa5b63ba33312c4f8) |
|---|---|
| 1.\" $NetBSD: ccd.4,v 1.5 1995/10/09 06:09:09 thorpej Exp $ 2.\" 3.\" Copyright (c) 1994 Jason Downs. 4.\" Copyright (c) 1994, 1995 Jason R. Thorpe. 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions --- 159 unchanged lines hidden (view full) --- 168.Nm 169and one of the disks fail, you cannot mount and use the remaining 170partition as itself; you have to configure it as a one-disk 171.Nm . 172You cannot replace a disk in a mirrored 173.Nm 174partition without first backing up the partition, then replacing the disk, 175then restoring the partition. | 1.\" $NetBSD: ccd.4,v 1.5 1995/10/09 06:09:09 thorpej Exp $ 2.\" 3.\" Copyright (c) 1994 Jason Downs. 4.\" Copyright (c) 1994, 1995 Jason R. Thorpe. 5.\" All rights reserved. 6.\" 7.\" Redistribution and use in source and binary forms, with or without 8.\" modification, are permitted provided that the following conditions --- 159 unchanged lines hidden (view full) --- 168.Nm 169and one of the disks fail, you cannot mount and use the remaining 170partition as itself; you have to configure it as a one-disk 171.Nm . 172You cannot replace a disk in a mirrored 173.Nm 174partition without first backing up the partition, then replacing the disk, 175then restoring the partition. |
| 176.Ss Linux compatibility 177The Linux compatibility mode does not try to read the label that Linux' 178md(4) driver leaves on the raw devices. You will have to give the order 179of devices and the interleave factor on your own. When in Linux 180compatibility mode, ccd will convert the interleave factor from Linux 181terminology. That means you give the same interleave factor that you 182gave as chunk size in Linux. | 176.Ss Linux Compatibility 177The 178.Tn Linux 179compatibility mode does not try to read the label that 180.Tn Linux Ns ' 181.Xr md 4 182driver leaves on the raw devices. 183You will have to give the order 184of devices and the interleave factor on your own. 185When in 186.Tn Linux 187compatibility mode, 188.Nm 189will convert the interleave factor from 190.Tn Linux 191terminology. 192That means you give the same interleave factor that you 193gave as chunk size in 194.Tn Linux . |
| 183.Pp | 195.Pp |
| 184If you have a Linux md(4) device in "legacy" mode, do not use the 185CCD_LINUX flag in | 196If you have a 197.Tn Linux 198.Xr md 4 199device in 200.Dq legacy 201mode, do not use the 202.Dv CCDF_LINUX 203flag in |
| 186.Xr ccdconfig 8 . | 204.Xr ccdconfig 8 . |
| 187Use the CCD_NO_OFFSET flag instead. In that case you have to convert 188the interleave factor on your own, usually it is Linux' chunk size 189multiplied by two. | 205Use the 206.Dv CCDF_NO_OFFSET 207flag instead. 208In that case you have to convert 209the interleave factor on your own, usually it is 210.Tn Linux Ns ' 211chunk size multiplied by two. |
| 190.Pp | 212.Pp |
| 191Using a Linux raid this way is potentially dangerous and can destroy 192the data in there. Since FreeBSD does not read the label used by 193Linux, changes in Linux might invalidate the compatibility layer. | 213Using a 214.Tn Linux 215RAID this way is potentially dangerous and can destroy 216the data in there. 217Since 218.Fx 219does not read the label used by 220.Tn Linux , 221changes in 222.Tn Linux 223might invalidate the compatibility layer. |
| 194.Pp 195However, using this is reasonably safe if you test the compatibility | 224.Pp 225However, using this is reasonably safe if you test the compatibility |
| 196before mounting a raid read-write for the first time. Just using 197ccdconfig without mounting does not write anything to the Linux raid. 198Then you do a fsck.ex2fs on the ccd device using the -n flag. You can 199mount the filesystem readonly to check files in there. If all this 200works, it is unlikely that there is a problem with ccd. Keep in mind 201that even when the Linux compatibility mode in ccd is working 202correctly, bugs in FreeBSD's ex2fs implementation would still destroy | 226before mounting a RAID read-write for the first time. 227Just using 228.Xr ccdconfig 8 229without mounting does not write anything to the 230.Tn Linux 231RAID. 232Then you do a 233.Nm fsck.ext2fs Pq Pa ports/sysutils/e2fsprogs 234on the 235.Nm 236device using the 237.Fl n 238flag. 239You can mount the file system read-only to check files in there. 240If all this works, it is unlikely that there is a problem with 241.Nm . 242Keep in mind that even when the 243.Tn Linux 244compatibility mode in 245.Nm 246is working correctly, bugs in 247.Fx Ap s 248.Nm ex2fs 249implementation would still destroy |
| 203your data. 204.Sh WARNINGS 205If just one (or more) of the disks in a 206.Nm 207fails, the entire 208file system will be lost unless you are mirroring the disks. 209.Pp 210If one of the disks in a mirror is lost, you should still --- 30 unchanged lines hidden --- | 250your data. 251.Sh WARNINGS 252If just one (or more) of the disks in a 253.Nm 254fails, the entire 255file system will be lost unless you are mirroring the disks. 256.Pp 257If one of the disks in a mirror is lost, you should still --- 30 unchanged lines hidden --- |