Greetings,
I need some advice but first the situation that drove me to look.
Basically, just spent the best part of three days doing some heavy lifting to recover data from a RAID 5 after having a double failure on my Synology DS916+ NAS after having 2*3TB WD Red drives fail. It's been in degraded and 'crashed' state so I've been able to get some stuff off, but it's driving me to distraction.
Screw Ups
Unfortunately, my sync to glacier was still going (plus it'd cost a fair bit to pull what is there), the disk I added to the array was older than I thought (though the same type), that failed, and the rebuild showed up a whole bunch of bad sectors on another disk during the rebuild so the NAS marked it as failing and went into limp mode.
I've had a look at the Backblaze data, my disks had a 3.5% annual failure rate, which explains some things; shame I never have that luck with the lottery.
Anyway, I'm looking at replacements.
So it seems to be that HGST wins, I was running 3 disk RAID 5. 1 disk is in the bin. Another is getting replaced under warranty. That leaves me with 2*3TB Western Digital Red's.
I'm thinking that I get two 4TB drives, use Synology Hybrid Raid with 2 disk redundancy (it died during a rebuild so I'm wary of hot spares), if I run out of space I can either use expansion units (bizarrely expensive) or hopefully just keep replacing drives with bigger ones as they get to the end of their warranty.
1 alternative is to have a 6 TB drive in the NAS and keep 1 disk redundancy in the main volume but replicate to the 6TB. More expensive (though only $110) and not sure it gives me anything.
It will all be replicated offsite, probably to google coldline rather than Glacier.
I'll have a replacement schedule to replace the drives when they are within 3 months of warranty, won't help reliability much but if I ebay the old drives it'll save some anxiety.
Does this sound sensible? Any ideas for how I can improve things without going crazy expensive.
I need some advice but first the situation that drove me to look.
Basically, just spent the best part of three days doing some heavy lifting to recover data from a RAID 5 after having a double failure on my Synology DS916+ NAS after having 2*3TB WD Red drives fail. It's been in degraded and 'crashed' state so I've been able to get some stuff off, but it's driving me to distraction.
Screw Ups
- One disk was out of warranty and I didn't realise.
- I extended the array from RAID1 to 5 with my second copy disk that holds the critical stuff before the array had finished syncing offsite.
- I tried to add the first failed disk back to the pool after testing it, it hadn't shown sector or I/O errors and Synology showed it as "not initialised", from reading people seem to think the Synology's are a bit over sensitive and often have zero problems when faced with the same situation. That was not true for me.
Unfortunately, my sync to glacier was still going (plus it'd cost a fair bit to pull what is there), the disk I added to the array was older than I thought (though the same type), that failed, and the rebuild showed up a whole bunch of bad sectors on another disk during the rebuild so the NAS marked it as failing and went into limp mode.
I've had a look at the Backblaze data, my disks had a 3.5% annual failure rate, which explains some things; shame I never have that luck with the lottery.
Anyway, I'm looking at replacements.
- HGST have empirical data showing they are the most reliable.
- HGST Deskstar drives only have a 3 year warranty. Ultrastars have a 5 year warranty but are twice as expensive
- Seagate have obviously had recent problems and seem to have a 3 year warranty on most things so I'm leaning towards them staying in the naughty corner.
- Western Digital can die in a ditch with Maxtor and Samsung as far as I'm concerned. It's not necessarily rational (and they own HGST now) but there it is.
So it seems to be that HGST wins, I was running 3 disk RAID 5. 1 disk is in the bin. Another is getting replaced under warranty. That leaves me with 2*3TB Western Digital Red's.
I'm thinking that I get two 4TB drives, use Synology Hybrid Raid with 2 disk redundancy (it died during a rebuild so I'm wary of hot spares), if I run out of space I can either use expansion units (bizarrely expensive) or hopefully just keep replacing drives with bigger ones as they get to the end of their warranty.
1 alternative is to have a 6 TB drive in the NAS and keep 1 disk redundancy in the main volume but replicate to the 6TB. More expensive (though only $110) and not sure it gives me anything.
It will all be replicated offsite, probably to google coldline rather than Glacier.
I'll have a replacement schedule to replace the drives when they are within 3 months of warranty, won't help reliability much but if I ebay the old drives it'll save some anxiety.
Does this sound sensible? Any ideas for how I can improve things without going crazy expensive.