On Fri, 04 May 2012 15:38:10 +0000, Camaleón wrote: > On Fri, 04 May 2012 10:48:36 +0000, Ramon Hofer wrote: > >> On Thu, 03 May 2012 20:27:02 +0000, Camaleón wrote: > >>> There's some useful information in one of the links I sent before: >>> >>> http://wiki.debian.org/LinuxRaidForAdmins >> >> Maybe I miss something but the page doesn't say anything about cli >> tools of the megaraid cards :-? > > Yes... no info is also info after all. Not the one you'd like to read > but that's how it is :-). Anyway, the page can be simply outdated or > lacking from that specific information. > > Also, the expanded information on the "megaraid_sas" driver points to > the page you sent before: > > http://hwraid.le-vert.net/wiki/DebianPackages > > Where you can find a set of tools for your driver ("megaclisas-status" > and "megacli") as well as more information about the LSI controllers and > the driver status: > > http://hwraid.le-vert.net/wiki/LSIMegaRAIDSAS > > Ufff, I was not aware of this: > > *** > There is currently no known opensource tool for theses cards. *** > > How, how bad... in contrast, 3ware seems to fully support open source, > or at least that's what it can be read here: > > http://hwraid.le-vert.net/wiki/3Ware > > *** > 3Ware supports Linux and provide an opensource kernel driver which has > been part of Linux for ages > *** > > This is something to reconsider.
Yes, this is really not what I wanted to read :-o So I think I'll just go for the LSI card and use mdadm. The 3Ware card I found at my dealer was twice the price of the LSI... <snipped> >>> Just an additional note. By reading the chosen card specs it seems it >>> does not support a RAID 6 level (which is better than RAID 5 because >>> it allows the failure 2 disks) so that can be a handycap. >> >> This should be no problem. I plan to use four slots without raid for >> mythtv. >> I already have a 4x 1.5 TB disks raid 5 and another 4x 2 TB disks raid >> 5. When I want to add more disks I can e.g. go for 3 TB disks and set 4 >> of them up as another raid5. >> Like this I can use disks with different sizes. > > Just a note of caution here. > > RAID 5 with big hard disks can be a real pain and a real problem. If one > of the arrays go down, the rebuilding operation can take up to "days" > (depending on the controller's capacity) and if while the RAID is > rebuilding a second disk of the array is also down for whatever reason > (it can be a false possitive) you can't recover your data, at least not > that easily. That's why most people is switching from raid 5 to raid 6, > it adds an extra of security with no remarkable drawbacks. That's true. On the other hand it isn't possible to have different disk sizes in a raid 6 neither. So my plan seems still reasonable to me to have several 4 disks raid 5 arrays. Like that I'm flexible to add bigger disks in future as they become cheaper and still can keep my old 1.5 TB disks. And if I would go for raid 6 with the 4 disk array I would loose a third of the capacity. >> I'm thinking of combining the arrays then to a lvm... But I don't know >> if this is a good idea as it adds more complexity :-? > > Yes, it will be a good idea (it will allow you to manage your volumes in > a more flexible manner) and yes, it will add an extra layer of > complexity (RAID+LVM) :-) Ok, hope it won't be too complicated :-) 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/jo309i$ma3$1...@dough.gmane.org
