On Sun, 06 May 2012 18:10:41 +0000, Camaleón wrote: > On Sun, 06 May 2012 17:44:54 +0000, Ramon Hofer wrote: > >> On Sun, 06 May 2012 15:40:50 +0000, Camaleón wrote: > >>> Okay. And how much space are you planning to handle? Do you prefer a >>> big pool to store data or you prefer using small chunks? And what >>> about the future? Have you tought about expanding the storage >>> capabilities in a near future? If yes, how it will be done? >> >> My initial plan was to use 16 slots as raid5 with four disks per array. >> Then I wanted to use four slots as mythtv storage groups so the disks >> won't be in an array. >> But now I'm quite fscinated with the 500 GB partitions raid6. It's very >> flexible. Maybe I'll have a harder time to set it up and won't be able >> to use hw raid which both you and Stan advice me to use... > > It's always nice to have many options and true is that linux softare > raid is very pupular (the usual main problem for not using is when high > performance is needed and when doing a dual-boot with Windows) :-)
Yes and I need neither of those things :-) >>>> You have drives of the same size in your raid. >>> >>> Yes, that's a limitation coming from the hardware raid controller. >> >> Isn't this limitation coming from the raid idea itself? > > Well, no, software raid does not impose such limit because you can work > with partitions instead. > > In hardware raid I can use, for example, a 120 GiB disk with 200 GiB > disk and make a RAID 1 level but the volume will be of just 120 GiB. (I > lose 80 GiB. of space in addition to the 50% for the RAID 1 :-/). But you can't build a linux software raid with a 100 GB and a 200 GB disk and then have 150 GB? >> You can't use disks with different sizes in a linux raid neither? Only >> if you divide them into same sized partitions? > > Yes, you can! In both, hardware raid and software raid. Linux raid even > allows to use different disks (SATA+PATA) while I don't think it's > recommended becasue of the bus speeds. What I mean was the space difference is lost in either ways? >>> I never bothered about replacing the drive. I knew the drive was in a >>> good shape because otherwise the rebuilding operation couldn't have >>> been done. >> >> So you directly let the array rebuild to see if the disk is still ok? > > Exactly, rebuilding starts automatically (that's a default setting, it > is configurable). And rebuiling always ends with no problem with the > same disk that went down. In my case this happens (→ the array going > down) because of the poor quality hard disks that were not tagged as > "enterprise" nor to be used for RAID layouts (they were "plain" Seagate > Barracuda). I did not build the system so I have to care about that for > the next time. I'd like using green drives for this system. So low power consumption is a thing I try keep low. And until now they worked well (one false positive in two years is ok) >>>> My 6 TB raid takes more than a day :-/ >>> >>> That's something to consider. A software raid will use your CPU cycles >>> and your RAM so you have to use a quite powerful computer if you want >>> to get smooth results. OTOH, a hardware raid controller does the RAID >>> I/O logical operations by its own so you completely rely on the card >>> capabilities. In both cases, the hard disk bus will be the "real" >>> bottleneck. >> >> I have an i3 in that machine and 4 GB RAM. I'll see if this is enough >> when I have to rebuild all the arrays :-) > > Mmm... I'd consider adding more RAM (at least 8 GB) though I would > prefer 16-32 GB) you have to feed your little "big monster" :-) That much :-O Ok, RAM is quite cheap and it shouldn't affect power consumption with in comparison to >20 hard disks. Best regards Ramon -- To UNSUBSCRIBE, email to debian-user-requ...@lists.debian.org with a subject of "unsubscribe". Trouble? Contact listmas...@lists.debian.org Archive: http://lists.debian.org/jo6jbv$2r9$1...@dough.gmane.org