2006/1/5, John Stoffel <john@xxxxxxxxxxx>: > > So what are you doing for backups, and can you allow the downtime > needed to restore all your data if there is a problem? Remember, it's > not the cost of doing backups which drives things, it's the cost of > the time to *restore* the data which drives issues. > Well, backups mean snapshots. Snapshots mean having a non-changing set of data for the time the backup goes. Not sure about that. Furthermore, backup means increasing the TCO per GB. I must keep it close to .50 euro per GB. That's my main issue at the moment... [....] > Why do you not want to use LVM? It gives you alot of flexibility to > change your mind down the road. Also, it means that you could just > build a pair of RAID5/6 arrays and stripe across them. Yes, you lose > some disk space since you now have multiple arrays, each with their > own parity disks, but it also means that > I don't trust it. I'm wrong I know, but I don't trust it. Had a very bad experience with a stupidly configured system (not configured by me, of course :-p) a couple of months ago, with a LVM on top of a linear Raid. Guess what ? Most of mission-critical data was lost. I know LVM was not responsible for this, but, you know, trust is sometimes not only a matter of figures and scientific facts. > In terms of filesystems, I still like ext3 for it's reliability, but I > would like a filesystem which can be resized on the fly if at all > possible. I've been slowly leaning towards xfs, but maybe that's > just me not liking Hans Reiser's attitude on the lkml at points. And > I certainly don't trust reiser4 at all yet, it's way too early for > production data. What did Hans say on LKML ? I thought he was considered as the gentle-and-wise-guru for filesystems, just as Linus is for the kernel... > Oh yeah, don't forget to mirror the root disk. And if you're looking > to make a file server, you might want to look at that OpenNAS stuff > and boot it off a compact flash card/USB dongle as well. Keep as few > a number of moving parts as possible. > Speaking of this, I began to think about splitting all the disks in two partitions : 1 of 1Go, the rest for data, and build two mds : md0, 12*1GB of raid1 (mirrored) for / md1, 12*229GB of raid6 for data. Maybe this is a little bit paranoïd for / but : 1. I can afford loosing 1GB of space on each DD 2. All disks have the same partition structure 3. I can boot on each DD, regardless to the number of valid DDs it has. BTW : is there any kind of limitation on the number of devices in a raid1 ? Of course, updating data on / will be at a high cost : 12 times for each write... But it's a fileserver, so config will not change so often (maybe an issue for logs...). - To unsubscribe from this list: send the line "unsubscribe linux-raid" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
