diff options
Diffstat (limited to 'debian/FAQ')
| -rw-r--r-- | debian/FAQ | 6 |
1 files changed, 5 insertions, 1 deletions
@@ -129,6 +129,9 @@ Also see /usr/share/doc/mdadm/README.recipes.gz 4b. Can a 4-disk RAID10 survive two disk failures? ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + I am assuming that you are talking about a setup with two copies of each + block, so --layout=near2/far2/offset2: + In half of the cases, yes [0], and it does not matter which layout you use. When you assemble 4 disks into a RAID10, you essentially stripe a RAID0 across two RAID1, so the four disks A,B,C,D become two pairs: A,B and C,D. @@ -138,7 +141,8 @@ Also see /usr/share/doc/mdadm/README.recipes.gz Thus, if you see a disk failing, replace it as soon as possible! If you need to handle two failing disks out of a set of four, you have to - use RAID6. + use RAID6, or store more than two copies of each block (see the --layout + option in the mdadm(8) manpage). 0. it's actually 1/(n-1), where n is the number of disks. I am not a mathematician, see http://aput.net/~jheiss/raid10/ |