43 ms·

This was using RAID 5, which in terms of reliability isn't great. It can recover from 1 disk failure, but as the recovery process is so intensive, it's likely a

by fy20 5y ago

This was using RAID 5, which in terms of reliability isn't great. It can recover from 1 disk failure, but as the recovery process is so intensive, it's likely another disk may fail during recovery - especially if they are all the same age. Other RAID setups can recover from two disk failures - but that's a trade-off with performance and useable space. Mixing drives from different manufacturers may help, but really you shouldn't rely on RAID alone. For commercial use you could duplicate the data on multiple NAS systems, but at home you probably aren't going to do that. Simplest is to understand RAID is not a backup, and to store the data somewhere else as well :-)

philjohn 5y ago
At home an offsite backup is going to be best - the initial backup though, especially on a cable internet connection is going to take weeks.
- Black101 5y ago
  > [...] the initial backup though, especially on a cable internet connection is going to take weeks. Initially, I drove my HDDs offsite... and I keep another offsite backup in my car.
  - kadoban 5y ago
    In the car is rather clever, I hadn't thought of doing that. I've been maintaining an offsite at a friend's house that I rotate out whenever I visit. The car would be a good extra. Encryption required, but I'm already doing that.
    - Black101 5y ago
      > In the car is rather clever, I'd give them credit but I forgot where I got that idea from ;) but I don't even encrypt mine because it has a higher chance of recovery that way.
  - ta988 5y ago
    Are you not worried about the temperature variations?
mysterydip 5y ago
When I was selling SANs, the conventional wisdom was RAID10 for production/performance stuff, and RAID6 for archival/"colder" storage. Plus an external or offsite backup, as you said.
- PaulHoule 5y ago
  I build quite a few RAID1 arrays for workstations and home servers. Normal performance and rebuild performance and even degraded performance are great. Hypothetically the RAID5 is more efficient but for me doubled 14TB drives are affordable and compact.
chiph 5y ago
Back during the dot-com era we lost a production array to the infamous "DeathStar" drives. The system reported a failure, so we scheduled the drive to be replaced and brought up the hot spare and started the parity resync process. A little while later there was another drive failure and we told the data center folks to tell the tech to hurry up. While the tech was headed to our cage, there was a third drive failure and the array was toast. We were able to restore from backup, but the data was a day old. Lessons were: Mix drives from different production batches (we couldn't mix manufacturers because of the leasing contract). Have a backup that you can restore from. Parity resync operations while the array is in use will put more stress on the drives than production use alone will, and will kill any (remaining) weak drives.
petee 5y ago
I thought RAID 5 was a no-go nowadays due to the high probability of rebuild causing a second failure?
- cerved 5y ago
  depends on your needs for redundancy

by fy20 5y ago

philjohn 5y ago

At home an offsite backup is going to be best - the initial backup though, especially on a cable internet connection is going to take weeks.

Black101 5y ago
> [...] the initial backup though, especially on a cable internet connection is going to take weeks. Initially, I drove my HDDs offsite... and I keep another offsite backup in my car.
- kadoban 5y ago
  In the car is rather clever, I hadn't thought of doing that. I've been maintaining an offsite at a friend's house that I rotate out whenever I visit. The car would be a good extra. Encryption required, but I'm already doing that.
  - Black101 5y ago
    > In the car is rather clever, I'd give them credit but I forgot where I got that idea from ;) but I don't even encrypt mine because it has a higher chance of recovery that way.
- ta988 5y ago
  Are you not worried about the temperature variations?

mysterydip 5y ago

When I was selling SANs, the conventional wisdom was RAID10 for production/performance stuff, and RAID6 for archival/"colder" storage. Plus an external or offsite backup, as you said.

PaulHoule 5y ago
I build quite a few RAID1 arrays for workstations and home servers. Normal performance and rebuild performance and even degraded performance are great. Hypothetically the RAID5 is more efficient but for me doubled 14TB drives are affordable and compact.

chiph 5y ago

Back during the dot-com era we lost a production array to the infamous "DeathStar" drives. The system reported a failure, so we scheduled the drive to be replaced and brought up the hot spare and started the parity resync process. A little while later there was another drive failure and we told the data center folks to tell the tech to hurry up. While the tech was headed to our cage, there was a third drive failure and the array was toast. We were able to restore from backup, but the data was a day old. Lessons were: Mix drives from different production batches (we couldn't mix manufacturers because of the leasing contract). Have a backup that you can restore from. Parity resync operations while the array is in use will put more stress on the drives than production use alone will, and will kill any (remaining) weak drives.

petee 5y ago

I thought RAID 5 was a no-go nowadays due to the high probability of rebuild causing a second failure?

cerved 5y ago
depends on your needs for redundancy