I'm building a linux traffic shaping routing box for a leased line connection. This box has to be reliable, so I'm planning on installing the operating system and data files on a RAID 1 configuration. My question is twofold:
I was going to use linux software raid. I have heard that hardware RAID really only gives any significant benefits once you shell out for a good quality RAID card - with a battery backup at least. I'm not too concerned with speed - I won't be using the disks much at all, but I am concerned with data recovery in case of an accident. Is shelling out for a hardware raid card worth the price? If so, can anyone recommend a card to use?
I've been in the situation before where hard disks bought at the same time failed at roughly the same time as well - i.e., within a week of each other. In order to avoid this, I'd like to populate my RAID array with disks from different manufacturers. As long as the disk sizes, speeds, and cache sizes are the same, can anyone see a problem with this?
Cheers,
Answer
1) Linux Software RAID is very mature these days, and removing drives from one machine and placing in another will work every time. With a hardware solution, you need to get a spare card because that particular chip's way of doing RAID may not be the same as another, and you may have lost your data. With modern CPUs, software RAID is safe to use and quick too - I'd trust it moreso than a hardware solution unless you've got the budget for a high-end RAID card. The benefits of these is that they have the battery backup units which store data in the case of a power outage. Typically, you're not really going to be affected by power outages though - the drives themselves tend to do caching as well, so you're going to lose some data anyway, just do Linux software RAID. Or ZFS - it's very nice, VERY safe, useful feature, but a different paradigm.
2) That'll be fine. As long as they're within about 1% of each other, you'll just get a RAID set of the smallest drive size. I do the same - I tend to stick with the same manufacturer, but get different build sets.
Remember that RAID is not backups, too.
No comments:
Post a Comment