| ccd.4 (9cbda59000e0f366b04c83d8d852c7c34b467722) | ccd.4 (3f4f4a1465e1b9e6174d6bac813020768efd18b3) |
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| 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. 183.Pp 184If you have a Linux md(4) device in "legacy" mode, do not use the 185CCD_LINUX flag in 186.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. 190.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. 194.Pp 195However, 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 203your data. |
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| 176.Sh WARNINGS 177If just one (or more) of the disks in a 178.Nm 179fails, the entire 180file system will be lost unless you are mirroring the disks. 181.Pp 182If one of the disks in a mirror is lost, you should still 183be able to back up your data. --- 29 unchanged lines hidden --- | 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 211be able to back up your data. --- 29 unchanged lines hidden --- |