SSD RAID or something else - Page 1
Forum section: electronics / general

author: tszaboo
author_rank: Super Contributor
timestamp: February 08, 2020, 09:31:02 pm
content: I've run into some computing problem today. So in my home desktop, I had this 240Gb SSD for the last 6 years. And it got used up. Every now and then Windows became a slog, drive write speeds dropped to 1MB/sec and the system just became absolutely unresponsive. It took me a lot of time to track it to the SSD.Fortunately, I keep backups. And this only has installed software, not actual data. But also reinstalling everything takes a huge amount of time (and even more to set up all the software with all the settings), so I tried cloning the drive... And now my saturday is gone. Because 2 software ended up not doing it, and searching for solutions, several CHKDSK and so on. Now I have a linux distro doing a clone, for the last 4 hours...So I dont want to deal with this sort of things, really. Seeing that a 512Gb SSD is like 50 EUR, I can throw in 2 in the computer, configure RAID 1 and hope for the best. Or is this the best way to keep the computer running, if a drive fails? Every 2 year, place a new drive in, throw out one of the old one, to keep the write levels down?Or do you guys just reinstall everything every few years?

author: oPossum
author_rank: Super Contributor
timestamp: February 08, 2020, 09:38:22 pm
content: My solution is eight SSD in RAID 6 with an LSI 9270 controller. I'm not suggesting that is a good solution, but it is tolerant of 2 drive failure and preforms almost as well as a ordinary NVME SSD (that I can't really use in my current system). It is all old stuff than can be had for cheap.

author: ogden
author_rank: Super Contributor
timestamp: February 08, 2020, 10:24:30 pm
content: Quote from: NANDBlog on February 08, 2020, 09:31:02 pmSSD rule #1: never fill drive completely with partition or files. Leave minimum 10% free space so drive have room for Garbage Collection (background erase), Wear Levelling and TRIM. Full SSD is slow because garbage collection can't keep-up, drive in result do not have enough pre-erased sectors for quick writes, it has to wait for erased sectors to become available. Erase+write obviously is much slower than write operation alone. AFAIK full SSD's wear-out (tend to fail) faster as well, yet it may differ from drive to drive make/model.Fully agree that RAID1 is next best thing you can do to your SSD & data.

author: tszaboo
author_rank: Super Contributor
timestamp: February 08, 2020, 10:45:25 pm
content: Quote from: ogden on February 08, 2020, 10:24:30 pmOh the slow write is not even the worst. It started to have bad sectors, that took a very long time to respond. So it was failing silently, and it was bringing my productivity down. Or spoiled the gaming night (yes, I do that sometimes). 6 years ago probably the GC wasnt that fleshed out, but they always overprovision the drives. This 240GB model probably had 256 GB Flash on it. BTW, cloning still in progress, I really hope I dont have to erase the new drive and start installing windows...

author: sokoloff
author_rank: Super Contributor
timestamp: February 08, 2020, 10:53:00 pm
content: From where you're starting, I'd be using Linux to do a dd clone of the drive to a new one (as it sounds like you're doing). Get the data off and leave the gimped drive set aside for a while. Then, see where you're at with that one performance-wise. (Verify that it was an SSD issue and not a Windows OS issue.)I'm a Mac guy for the last 4-5 years and have done several machine migrations, with this most recent one being the only one that I set up from scratch again. In the Windows world, I used to pave and re-install my machine every couple of years back in the 3.1/NT/XP/7 days. I had a Server2K8 machine that ran well for 6+ years as a daily driver, with no re-paves and no boot drive changes. Not enough experience with 10 yet to say (my parents run 10 and so I get roped in to support them at times).I wouldn't think that going to RAID 1 on new drives would solve the issue you're facing now. Going to bigger drives (500GB) and under partitioning them (allocate 300 GB and leave 200GB for wear leveling and remapping) might help. I use backups to protect my data and I'm willing to go reinstall apps if I ever need to do so.

author: ogden
author_rank: Super Contributor
timestamp: February 08, 2020, 11:42:27 pm
content: Quote from: NANDBlog on February 08, 2020, 10:45:25 pmThat "hardware overprovisioning" usually is not enough. 240GB available out of 256GB is 6% which is more like spare sector pool rather than garbage collector sandbox for system/work drive. When I say 10% free, I mean - in addition to hardware overprovision. The more you care about your data - the bigger chunk of SSD you want to leave free, up-to 20% of available space, especially for cheap consumer grade SSD's.Samsung Over-Provisioning-White-paperexplains in quite details why you would want to leave up-to 20% of your SSD free.It's sad that internet search first hits are forum posts where clueless people tell complete BS about "it is not a thing anymore for at least 6 years".

author: David Hess
author_rank: Super Contributor
timestamp: February 09, 2020, 03:45:59 am
content: Quote from: oPossum on February 08, 2020, 09:38:22 pmThat will soon be my solution as well but I have been using RAID 5 for 10+ years on an Areca ARC-1210 and will be moving to RAID 6 on an Areca ARC-1220 shortly. The Areca controllers are fast enough with hard drives that I only use SSD for swap and temporary files.I have been messing around with software RAID for bulk storage but have not been impressed by the speed.

author: gnif
author_rank: Unknown
timestamp: February 09, 2020, 04:06:52 am
content: Quote from: ogden on February 08, 2020, 11:42:27 pmThat's not hardware overprovisioning... its a matter of KiB vs KB, ie, 1024 vs 1000 bytes per order of magnitude. Hard disks sizes are specified using 1000 bytes per KB, 1000 KB per MB, 1000 MB per GB, etc.256GB = (256*1000*1000*1000)/1024/1024/1024 = 238.419 GiB

author: Monkeh
author_rank: Super Contributor
timestamp: February 09, 2020, 05:33:35 am
content: Quote from: gnif on February 09, 2020, 04:06:52 amPerhaps ogden is mixing up his prefixes... a 256GB SSD will have 256GiB of flash. As will a current 240GB SSD.

author: Ed.Kloonk
author_rank: Super Contributor
timestamp: February 09, 2020, 05:42:08 am
content: Judging by what you describe (age and size of drive), is your SSD a Samsung Evo 840?Might work better with a firmware update.https://www.anandtech.com/show/8997/samsung-releases-statement-on-840-evo-performance-another-fix-is-in-the-works

author: tszaboo
author_rank: Super Contributor
timestamp: February 09, 2020, 08:09:08 am
content: Quote from: sokoloff on February 08, 2020, 10:53:00 pmYes, I puthttps://clonezilla.orgon a USD drive, booted from it and cloned the SSD with the -rescue option. It took a very long time. But the computer lives for now.Quote from: sokoloff on February 08, 2020, 10:53:00 pmYeah, every 2-3 years you got a better OS, better hardware and the OS typically crapped itself, so you had a recovery CD handy. This PC had this SSD since day 1, the only time it had a BSOD, is when some chinese USB-serial converter driver crashed it, and I didnt really see a reason to update, given it had 4 cores and reasonable speed. Now, I'm looking at the new AMD processors, maybe it is time to upgrade.The way I see it, I'm not even going to have spinning rust in my new PC, only SSDs.Quote from: Ed.Kloonk on February 09, 2020, 05:42:08 amIt is a PNY branded one. I'm not really looking into saving it. I'll see if the new drive survives for a week, then wipe the old one.Quote from: David Hess on February 09, 2020, 03:45:59 amI've been reading about RAID for some time now, and people say that hardware raid is not that great. The reason being nothing saves the data, if your controller fails.

author: ogden
author_rank: Super Contributor
timestamp: February 09, 2020, 09:07:27 am
content: Quote from: Monkeh on February 09, 2020, 05:33:35 amI was just addressing this post:Quote from: NANDBlog on February 08, 2020, 10:45:25 pmIf I am missing something- it is even worse for those who say that there is no need for "user overprovision". Oh, BTW seems like none of you did read Samsung whitepaper. That's shame.

author: tszaboo
author_rank: Super Contributor
timestamp: February 09, 2020, 09:18:59 am
content: Quote from: ogden on February 09, 2020, 09:07:27 amIts the typical "leave space empty on SSD because thats good" white paper. I moved a 240GB partition to a 256GB SSD, rest is not partitioned. Happy?

author: Karel
author_rank: Super Contributor
timestamp: February 09, 2020, 10:23:41 am
content: In my experience, the Samsung Pro series are the most reliable ssd's available.You'll pay more but I believe it's worth it.

author: ogden
author_rank: Super Contributor
timestamp: February 09, 2020, 10:54:02 am
content: Quote from: NANDBlog on February 09, 2020, 09:18:59 amI don't care you agree or not. This is public forum, not private email conversation, I am not your mom as well. Other people may find information in this thread as useful.

author: kripton2035
author_rank: Super Contributor
timestamp: February 09, 2020, 11:06:21 am
content: Quoteexcept if you have an external backup... which you must always have for EVERY drive system you may use.

author: SiliconWizard
author_rank: Super Contributor
timestamp: February 09, 2020, 04:14:52 pm
content: Quote from: Karel on February 09, 2020, 10:23:41 amI also recommend that. That's what I use.The points made above still hold. Set up some comfortable overprovisioning. Or don't fill up your drives.As to data integrity... I personally have never set up RAID arrangements for a workstation. I leave that to NAS systems with a lot of data (for which frequent backups are not practical), and do frequent backups on workstations instead.I also change drives every few years and never wait till they fail. That usually corresponds to new generations of drives with better performance anyway. Again for workstations. For NAS/file server use, with often a number of large drives, it would be expensive to do that, and with a RAID-5 arrangement, I've never had a problem. I've had one drive failure overall, just replacing it did the trick with no down-time (except a few minutes for the replacement.)

author: sokoloff
author_rank: Super Contributor
timestamp: February 09, 2020, 05:00:42 pm
content: This is meant as 80% “yes, and” and only 20% “yes, but”.It’s wise to remember that RAID is an availability enhancer against hardware failures, but is not a substitute for backups. An application or user error or malicious action (cryptolocker) can take out your RAID array in a way that backups would save you but RAID won’t. (A snapshotting filesystem will mitigate against some of these risks, of course.)Single disk redundancy (RAID 5 or RAIDZ1) is somewhat risky, especially if you don’t have a periodic scrubbing process across your volumes. When a single disk fails in this situation, any further unrecoverable errors on the reminding disks during the rebuild are, well, unrecoverable. That led me to switch to RAID6 (and later RAIDZ2) for our family NAS storage. We also backup most of the user-generated data off-site and all of the critical user-generated content (family photos, mostly) to two off-site stores.RAID5 is way better than what most end users are doing, of course.

author: oPossum
author_rank: Super Contributor
timestamp: February 09, 2020, 05:15:57 pm
content: Quote from: NANDBlog on February 09, 2020, 08:09:08 amRAID is about high availability and/or performance. If a drive fails you can keep working while that drive is rebuilt. Performance will be bad, but you have no down time. Replacing an LSI/Avago/Broadcom controllers is not a problem. They will happily import a foreign array. HPE controllers are absolute garbage. They loose arrays for numerous reasons and no way to recover.I run daily backups to a HDD in the same system, weekly backups to two external HDD, and monthly offsite backups. If you don't do routine backups consider your data lost. External HDD are cheap - there is no reason not to do at least weekly backups.

author: rdl
author_rank: Super Contributor
timestamp: February 09, 2020, 06:34:56 pm
content: I put almost nothing on the boot drive besides Windows (7). Programs, games, and short term data go on a separate drive which is synced periodically to another disk. Important stuff and nedia files go on a NAS.Windows 7 built in backup is okay for itself with some limitations.

author: David Hess
author_rank: Super Contributor
timestamp: February 10, 2020, 12:36:26 am
content: Quote from: NANDBlog on February 09, 2020, 08:09:08 amControllers are reliable enough that I do not consider them a limitation and if they do fail, there is a thriving used market to get a replacement.Quote from: sokoloff on February 09, 2020, 05:00:42 pmI consider scrubbing to be one of the weaker points of RAID because some manufacturers just handle it poorly or it affects performance so much that it is painful to use. I have a Netgear NAS (software RAID) which was given to me where a large load while scrubbing causes the SMB server to lock up; Netgear never fixed it of course.Quote from: rdl on February 09, 2020, 06:34:56 pmI do the same thing. As much as possible, I keep programs and data on volumes separate from the boot volume containing Windows. With every release of course, Windows makes this more difficult and now encourages storage in the Cloud. One of the things I like about Steam is that now it lets you pick were a game is installed; that used to be a huge problem with games getting larger and larger.

author: nigelwright7557
author_rank: Frequent Contributor
timestamp: February 10, 2020, 01:04:56 am
content: Using RAID will wear out two or more drives at the same time but will be just about bomb proof.I have two 512GB SSD's.One is main drive and second one holds backups.I backup specific directories every time I make a change to anything important.This seems to have worked well for me and doesnt wear out second drive.I also use a 128GB USB flash drive and backup to that occasionally and keep it in the car in case of fire in the house.The most important files I also save to a DVD now and then.I got caught out in 2006 when I did a clean install of Windows on my PC.For some reason the install decided to format both drives !I managed to dig out DVD's but a lot was lost.

author: tszaboo
author_rank: Super Contributor
timestamp: February 10, 2020, 11:22:26 pm
content: Quote from: nigelwright7557 on February 10, 2020, 01:04:56 amThe plan is to stagger the SSD, so buy them with a year in between. And to use different brand, to avoid controller caused problems. And I have a server in the garage with HDD for backup. I havent touched a DVD for a decade. Interestingly, there doesn't seem to be a PROM with SSD size, I really dont understand why.

author: ogden
author_rank: Super Contributor
timestamp: February 10, 2020, 11:38:28 pm
content: Quote from: NANDBlog on February 10, 2020, 11:22:26 pmYou have to be careful with DVD archiving, know what you are doing. Further reading:http://www.thexlab.com/faqs/opticalmedialongevity.html

author: nctnico
author_rank: Super Contributor
timestamp: February 11, 2020, 01:11:14 am
content: Quote from: NANDBlog on February 08, 2020, 09:31:02 pmI'd just get one big SSD from a good brand (like the Samsung Pro models) and use a low energy / low noise HDD for a nightly backup.Also consider getting an NVME SSD on a PCI-express card. SATA is a serious bottleneck nowadays compared to 4 lanes on a PCIexpress bus.

author: ogden
author_rank: Super Contributor
timestamp: February 11, 2020, 01:20:05 am
content: Quote from: nctnico on February 11, 2020, 01:11:14 amAlso check S.M.A.R.T data of your drives. Samsung have wear leveling measure which starts at 100 when new and ends with 5 when you (your data) are in trouble.

author: james_s
author_rank: Super Contributor
timestamp: February 11, 2020, 01:38:22 am
content: It's usually a good idea to have some free space on a drive, operating systems tend to not behave well if a drive gets *conpletely* full. I've never heard of anyone leaving unpartitioned space until this thread though, that's a bit silly IMO, SSDs are already overprivisoned.Also no matter what setup you use, backups are mandatory. Drives of all types can fail at any time without warning, if you have a backup it's not a catastrophe.