Topic: Upgrading to v10. RAID. Or RANSID.

[ReetP]

So, lots of you will be wanting to move your SME to new hardware as part of your upgrade.

Before you go racing into buying your new Redundant Array of Inexpensive Drives (and to those of you who have already done so) you really need to read this article.

https://raid.wiki.kernel.org/index.php/Timeout_Mismatch

Read some of the links on SMR drives as well.

In essence a number of hard drive manufacturers have slipped out new technology into hard drives which means that they can fail on a RAID rebuild. Particularly of concern are WD Red NAS drives - notably the 3.5" 2-6Tb (and may be larger) - which are the drive of choice for many.

Check these. If yours is SMR it is NOT suitable for RAID at ALL. You can RMA an existing drive. I would, fast.

Note, removing and rebuilding will then stress the other drives. You are going to need some VERY careful planning to migrate this. Make sure you have LOTS of backups.

https://blog.westerndigital.com/wd-red-nas-drives/

The side effect of this is I have a new acronym for you now.

Redundant Array of Not So Inexpensive Drives

"RANSID"

[Parsival1973]

Insert groan here.

[alanh]

Thanks for that info - so reading the article it seems WD Red Plus (CMR) should be ok for RAID1.  Specifically what would be the max disk size for this release?

Thanks

[ReetP]

Insert groan here.

[ReetP]

Thanks for that info - so reading the article it seems WD Red Plus (CMR) should be ok for RAID1.  Specifically what would be the max disk size for this release?

They should - but make sure that is what they are. Test thoroughly before committing to use them.

Max size will be based on whatever the max is in Centos/RHEL 7 - that is the base and we don't mess with that. Just make sure your hardware is capable of supporting it too. Note there are options for using xfs or ext4 - I think the default is now xfs.

Another point to think about is rebuild times on a RAID 1 with really big drives. The chances of failure will increase.

So.

• Make sure you have really good backups
• Preferably run a 3rd ACTIVE drive in your mirror so if one fails you still have two drives (then start to ask yourself why you are using RAID 1)
• Consider a bundle of smaller drives and use something like RAID 6

HTH