Gary Dale <extremegroundmai...@gmail.com> writes: > On 04/12/14 12:51 PM, Dan Ritter wrote: >> On Thu, Dec 04, 2014 at 02:13:59PM +0100, mad wrote: >>> Hi! >>> >>> I wanted to create a RAID5 with lvm. The basic setup is something like >>> >>> lvcreate --type raid5 -i 2 -L 1G -n my_lv my_vg >>> >>> which would mean 3 physical drives would be used in this RAID5. But can >>> I specify that one drive is missing as it is possible with mdadm? >> I don't think so, no. You can create your RAID with mdadm and >> put LVM on top of that. >> >> In general I strongly recommend against using RAID5. RAID1, 10, >> or 6 are all better options if your data's availability is >> important to you. >> >> -dsr- >> > Sorry, but there are good reasons to use RAID 5 and better reasons to > NOT use RAID 10. RAID 1 and RAID 5 are both immune to single disk > failures in their most common configurations (1 or more data disks > with 1 parity disk).
The problem is not that RAID5 does not provide resilience against a single disk failure. The problem is that with modern disk capacities, the chances of *another* disk failing while the array is rebuilding have significantly risen. Especially when all the disks came out of the the same batch, they tend to fail at similar times. I know Best Practice is to mix disks in RAID arrays, but who actually practices that, instead of just taking the risk of failure and covering it with a higher RAID level, like RAID6 in this case? -- "We will need a longer wall when the revolution comes." --- AJS, quoting an uncertain source. -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: https://lists.debian.org/86y4qm76vi....@gaheris.avalon.lan