On 6/23/2011 1:43 PM, Krzysztof Adamski wrote: > Hi All, > > I have a raid6 array made out of 8 1.5T drives and I wanted to change to > use 3T drives. The array is 0.90. After reading the wiki I see that 0.90 > superblock will not work with any device larger then 2T. > > What are my options for a live upgrade (backup/restore is not possible)? The best way to do this, given that you have no backup, is to add a known-to-work-with-Linux SAS/SATA HBA and build a new md array and format it with a fresh filesystem. Let the 8 new drives spin for a couple of days. If all 8 drives are still kicking, copy everything over from the current filesystem with a 'cp -a' or similar method. If you have NFS/Samba shares or other filesystem specific mappings, rsync, etc, edit your conf files to point to the new filesystem/device. Run in production with the new array for a few days or a week to make sure it's working correctly, then remove the old array at your leisure. This staged multi step approach gives you the best chance to avoid data loss during the migration as even after it's complete you still have the existing array fully intact until you decide to remove it. It is much safer than rebuilding an 8 disk array one disk at a time. It also puts much less wear and tear on the new drives. Another benefit is that after copying the files over, the new filesystem will be much less fragmented than in the case of rebuilding the existing array one drive at a time. If you don't have 16 disk bays and sufficient SAS/SATA ports in your current chassis, and you can't leave a side panel off with the 8 new drives simply sitting on a desk during the transition, then you should grab an external enclosure, either desktop or rackmount, whichever fits your needs, and an external version of the HBA. Some options are: If you have 16 bays or can sit the new 8 drives on the desk next to the server during the upgrade just grab one of these cheap LSI based Intel 8 port HBAs: http://www.newegg.com/Product/Product.aspx?Item=N82E16816117157 If you must go external, take a look at these. A bit more costly, but a better solution in the long run. It'll also allow you to keep your existing array instead of replacing it. If you go with the rackmount unit adding a 4 port HBA in the future will allow you to add 4 more drives. Each row of 4 drives has its own SFF8088 port on the back. http://www.newegg.com/Product/Product.aspx?Item=N82E16816118116 http://www.newegg.com/Product/Product.aspx?Item=N82E16816111092 http://www.newegg.com/Product/Product.aspx?Item=N82E16816133044 -- Stan -- 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
