I picked up a pair of 6TB Toshiba X300 for $170 each. I can return them through the end of January with free shipping and no restocking fee, so long as I don’t open the retail boxes. My plan was to see if a better deal came along this weekend, either cheaper desktop drives or slightly more expensive NAS drives.
My understanding is that there are two features that make a desktop drive undesirable for use in a NAS. The first is that if a bad sector is encountered, a desktop drive will spend a lot of time trying to read that sector and the RAID controller will think it failed. WD Reds have TLER which essentially disable this behavior. The second feature is relatively aggressive head parking in desktop drives. I’ve seen conflicting information as to whether or not this is really a bad thing. I’m inclined to believe that head parking may induce a slightly longer seek time, but otherwise is not an issue. The head moves countless times throughout its life, I can’t imagine that parking it a few thousand times a year is an issue.
My system is used 90% for media storage / downloading, 5% Owncloud server for my phone’s camera, and 5% “hey that’s an important file I should keep.” Everything except for the OS is backed up to Crashplan’s servers and also encrypted and stored on ACD.
I currently have qty 6 of 2 TB drives in RAID 1. I believe I will add my new drives to the existing pool instead of making a new pool.
So here’s my questions:
Does a lack of TLER-like behavior have a negative affect on the software raid used by Rockstor in case of a bad sector?
Is there any way for Rockstor / bash to enable TLER-like behavior on a Toshiba drive?
Am I stupid for using a couple of these drives in my system?
All three of them have worked flawlessly, without problems.
Checking up on them with Philip’s suggested commands, they are not set up for TLER as per standard, but all three of them accepts the commands to set it up. And after that it seems to work. I set them up with the same timeout as a WD NAS drive I have in my system. Strangely a Seagate NAS drive I also have in the system, was not set up for TLER either, so I set that up too.
If Philip gets away with integrating this into the Rockstor UI, so that these settings are setup during every boot, I don’t see why there should be any problems using these drives. In my experience they are just as reliable as dedicated NAS drives. Although my sample group is very small
Edit:
Wikipedia says this about TLER and ZFS:
Interaction of TLER with the advanced ZFS filesystem
The ZFS filesystem was written to immediately write data to a sector that reports as bad or takes an excessively long time to read (such as non TLER drives); this will usually force an immediate sector remap on a weak sector in most drives.
I dont know if BTRFS is written in a similar maner, but if it is, lack of TLER does not seem to be a serious problem as it is basically handled by the FS.
Throwing my two cents in here. I wouldn’t worry about using desktop drives or even TLER honestly. BTRFS will take care of that by itself. TLER is useful though when you are using a hardware RAID solution which BTRFS is not.
I’m personally running desktop drives exclusively with no issues. So long as there is redundancy it simply pulls the data from the good drives and ignores the bad ones. Your weekly(ish) scrub will show any drives that have ify sectors as having errors.
Thanks for the information everyone. I ran a long smartctl test on the two new drives last week (badblocks wouldn’t run as the drives were too large) and installed them last night. Running a rebalance on them right now (but that is giving me an issue, a topic for another thread though) and I’ll check out the support thread regarding TLER @phillxnet linked.
Thanks again, I look forward to having ample spare space and good performance soon!
