Comments for The 9 Minute Snooze http://blog.9minutesnooze.com Photography, Tech, and more Fri, 20 Jan 2012 18:57:04 +0000 hourly 1 Comment on RAID 10 your EBS data by Marc http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-25226 Marc Fri, 20 Jan 2012 18:57:04 +0000 http://blog.9minutesnooze.com/?p=356#comment-25226 Anyone know of a way to do this with Windows instances? Thanks. Anyone know of a way to do this with Windows instances? Thanks.

]]> Comment on RAID 10 your EBS data by Aaron http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-20283 Aaron Thu, 10 Nov 2011 15:35:59 +0000 http://blog.9minutesnooze.com/?p=356#comment-20283 Henri - as I mentioned in my article, the issue is not about drive failure in the conventional sense. Amazon does protect you against a SATA drive crashing. What Amazon does not protect against is sudden performance degradation or failure of the EBS technology itself. Theory is great, but I was in the trenches when EBS failed. When seemingly half the Internet was down for 4 days, we were only out for 45 minutes or so in the middle of the night. This was entirely because of our replication topology and usage of EBS with RAID10. Henri – as I mentioned in my article, the issue is not about drive failure in the conventional sense. Amazon does protect you against a SATA drive crashing. What Amazon does not protect against is sudden performance degradation or failure of the EBS technology itself.

Theory is great, but I was in the trenches when EBS failed. When seemingly half the Internet was down for 4 days, we were only out for 45 minutes or so in the middle of the night. This was entirely because of our replication topology and usage of EBS with RAID10.

]]> Comment on RAID 10 your EBS data by Henri http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-20226 Henri Wed, 09 Nov 2011 15:24:37 +0000 http://blog.9minutesnooze.com/?p=356#comment-20226 EBS volumes are SAN partitions isn't it and Amazon is pretty clear about the fact that each EBS volume has redundancy built in and that adding additional redundancy is not particularly recommended (at that point other failure modes dominate anyway). Did some of you get errors/problems with EBS drives allready (except major zone failure as we get some month ago). I'll be very interesting about LVM of EBS vs RAID of EBS. Cheers EBS volumes are SAN partitions isn’t it and Amazon is pretty clear about the fact that each EBS volume has redundancy built in and that adding additional redundancy is not particularly recommended (at that point other failure modes dominate anyway).

Did some of you get errors/problems with EBS drives allready (except major zone failure as we get some month ago).

I’ll be very interesting about LVM of EBS vs RAID of EBS.

Cheers

]]> Comment on RAID 10 your EBS data by Gunners http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-18961 Gunners Fri, 14 Oct 2011 20:40:15 +0000 http://blog.9minutesnooze.com/?p=356#comment-18961 @Joshua - I think I had a similar experience ( not sure because I don't remember the exact error message ). The thing that fixed it for me was this command mdadm --assemble --scan Our configuration includes RAID 10 setup with 4 drives (each of 100 GB giving a total capacity of 200G). We are not sure how much data we will get, but I think a day will come when we will go past 200G. So, I was thinking of putting this RAID10 structure under LVM from the start. Then when the day comes, I will just add 4 new drives (off some xxx size), and add the new raid10 device to my logical volume.. I have little clue about how sound this strategy is.. Any comments here will help.. Thanks.. @Joshua – I think I had a similar experience ( not sure because I don’t remember the exact error message ). The thing that fixed it for me was this command
mdadm –assemble –scan

Our configuration includes RAID 10 setup with 4 drives (each of 100 GB giving a total capacity of 200G). We are not sure how much data we will get, but I think a day will come when we will go past 200G. So, I was thinking of putting this RAID10 structure under LVM from the start.

Then when the day comes, I will just add 4 new drives (off some xxx size), and add the new raid10 device to my logical volume..

I have little clue about how sound this strategy is.. Any comments here will help.. Thanks..

]]> Comment on RAID 10 your EBS data by Aaron http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-18204 Aaron Wed, 28 Sep 2011 18:07:43 +0000 http://blog.9minutesnooze.com/?p=356#comment-18204 @Joshua - as far as I know, it's possible, but you have to mess with the superblock. I have seen solutions that simulate RAID10 by creating multiple RAID1 arrays and use LVM to effectively RAID0 the RAID1 arrays, thus creating a hybrid RAID10. I have not tried it myself, but it seems like a good solution. It also allows you to know exactly which disks can be safely failed out, something that is difficult to discern with md. My next post, when I get some time to finish it up, is going to cover expanding disks. Maybe I test and add this LVM piece in there. @Joshua – as far as I know, it’s possible, but you have to mess with the superblock. I have seen solutions that simulate RAID10 by creating multiple RAID1 arrays and use LVM to effectively RAID0 the RAID1 arrays, thus creating a hybrid RAID10. I have not tried it myself, but it seems like a good solution. It also allows you to know exactly which disks can be safely failed out, something that is difficult to discern with md.

My next post, when I get some time to finish it up, is going to cover expanding disks. Maybe I test and add this LVM piece in there.

]]> Comment on Get Hulu working on Boxee (again) by phwelo http://blog.9minutesnooze.com/hulu-working-boxee/comment-page-1/#comment-18089 phwelo Sun, 25 Sep 2011 23:22:09 +0000 http://blog.9minutesnooze.com/?p=309#comment-18089 Just went ahead and gave this a shot on windows xp htpc i was working on. found that it still works, kind of. Fullscreen is a no-go as i saw mentioned above. Also the playback is super laggy. I'm truly surprised there hasn't been more work done to polish this method. Then again maybe there is and I just wasn't able to search it out Just went ahead and gave this a shot on windows xp htpc i was working on. found that it still works, kind of. Fullscreen is a no-go as i saw mentioned above. Also the playback is super laggy. I’m truly surprised there hasn’t been more work done to polish this method. Then again maybe there is and I just wasn’t able to search it out

]]> Comment on RAID 10 your EBS data by Joshua Warchol http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-17449 Joshua Warchol Sat, 10 Sep 2011 15:52:28 +0000 http://blog.9minutesnooze.com/?p=356#comment-17449 Thanks for the great post Aaron. The Percona Live video was very helpful too, wish I'd been able to make it to that conference. Any advice on how to grow an EBS RAID10 array? I've seen comments online that it's both impossible and possible. I assume it's something along the lines of stopping the md, snapshotting the volumes, creating new larger volumes from the snapshot, attaching those in place of the originals, and then some magic I'm missing. Any ideas? I get this error when trying to re-assemble: mdadm: no recogniseable superblock on /dev/sdm1 mdadm: /dev/sdm1 has no superblock - assembly aborted Thanks again, and rock on! Thanks for the great post Aaron. The Percona Live video was very helpful too, wish I’d been able to make it to that conference.

Any advice on how to grow an EBS RAID10 array? I’ve seen comments online that it’s both impossible and possible. I assume it’s something along the lines of stopping the md, snapshotting the volumes, creating new larger volumes from the snapshot, attaching those in place of the originals, and then some magic I’m missing. Any ideas?

I get this error when trying to re-assemble:

mdadm: no recogniseable superblock on /dev/sdm1
mdadm: /dev/sdm1 has no superblock – assembly aborted

Thanks again, and rock on!

]]> Comment on RAID 10 your EBS data by Aaron http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-16544 Aaron Thu, 18 Aug 2011 15:47:50 +0000 http://blog.9minutesnooze.com/?p=356#comment-16544 Unfortunately, there is no way to control where your disks are spun up in the Amazon infrastructure, but I have never experienced the issue you are describing. However, Amazon has extensive redundancy within their infrastructure - it's not as if an EBS volume == a single SATA drive (even though performance is similar). Behind the scenes, there is extensive mirroring performed by Amazon. Unfortunately, there is no way to control where your disks are spun up in the Amazon infrastructure, but I have never experienced the issue you are describing. However, Amazon has extensive redundancy within their infrastructure – it’s not as if an EBS volume == a single SATA drive (even though performance is similar). Behind the scenes, there is extensive mirroring performed by Amazon.

]]> Comment on RAID 10 your EBS data by Lawrence Pit http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-16539 Lawrence Pit Thu, 18 Aug 2011 14:38:28 +0000 http://blog.9minutesnooze.com/?p=356#comment-16539 Awesome post. Question: as the volumes created are virtualized by amazon, there is a chance that all 8 or 10 are created on the exact same physical disk, therefor when that physical disk loses say power, then the complete raid10 array is down? Any tricks to ensure the created volumes are in fact on different physical disks and power supplies? (or does this go beyond the purpose of raid?) Awesome post. Question: as the volumes created are virtualized by amazon, there is a chance that all 8 or 10 are created on the exact same physical disk, therefor when that physical disk loses say power, then the complete raid10 array is down? Any tricks to ensure the created volumes are in fact on different physical disks and power supplies? (or does this go beyond the purpose of raid?)

]]> Comment on RAID 10 your EBS data by Kobi biton http://blog.9minutesnooze.com/raid-10-ebs-data/comment-page-1/#comment-15821 Kobi biton Tue, 02 Aug 2011 13:33:50 +0000 http://blog.9minutesnooze.com/?p=356#comment-15821 Aaron thanks for the detailed reply , I probably will need to stop the splunk server for a consistent snapshot I have a conf. call with their eng. will ask this question worse come to worse I will use LVM2 which deals with the consistency issue will update. Thanks! Kobi. Aaron thanks for the detailed reply , I probably will need to stop the splunk server for a consistent snapshot I have a conf. call with their eng. will ask this question worse come to worse I will use LVM2 which deals with the consistency issue will update.

Thanks!
Kobi.

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