Preclearing disks when there's no more empty SATA ports

[tyrindor]

I was wondering how people go about Preclearing new disks when they run out of SATA ports. I have 4 drives to preclear, and doing them one at a time could take over a week. I've thought of making a trial unRAID USB stick on a second computer and running them that way, but that seems like a lot of work. The other option would be to remove drives from the server, put in the new disks while keeping the array offline, preclear, and put everything back afterwards. However, that's downtime.

 

Can I just buy some type of external enclosure and connect it up via USB? This seems to be a common problem for me.

[dirtysanchez]

I use another machine to do the preclears, with either a trial key, or my second unRAID key.

 

If I recall correctly you can preclear a drive via USB, but it's quite a bit slower (with USB 2.0 anyway, never tried it with USB 3.0), and SMART reports may or may not work via USB.

[garycase]

As noted above, you can simply do the pre-clears on a different machine.

 

HOWEVER ... I gotta ask ==>  You have a motherboard with 6 SATA ports and 3 MV8 controllers ... for a total of 30 SATA ports !!    Do you not have any spares for pre-clears

 

[Frank1940]

I use my Test Bed server to preclear disks.  At the present time, I have two unused hot-swap drive housings installed that I can use for preclearing.  To be perfectly honest, I never hot-swap as I am just old fashion enough not to plug and unplug electronics with power on.  But those housings sure do made it quick and easy to load and unload drives! 

 

If you considering a way to do four drives at once, you might want to find out how much memory each preclear shell is going to require. I seem to recall that it has a big memory footprint...

 

Oh, if I recall currectly, drives that are being precleared are not included in the array count so you could use version 5 in the unregistered mode to preclear four drives at once.  And the preclear script does exactly the same job on ver 5 and 6 so you can use a precleared disk from one version in the other. 

[garycase]

... To be perfectly honest, I never hot-swap as I am just old fashion enough not to plug and unplug electronics with power on.

 

Almost ditto 

 

I am VERY cautious about hot-plugging electronics => NEVER hot-plug PS/2 ports; video connections except HDMI; IDE connections; and many others.  I DO hot-plug USB ports (they're designed for it); HDMI connections (also designed for it); and will VERY CAREFULLY do it with SATA drives in my eSATA dock after I "Safely Remove" them in Windows and get the appropriate "Okay to remove" message.    I do NOT hot-plug in Linux, as there's no "safely remove" function (as least not that I'm aware of).

 

But the safest approach is to always plug/unplug on a system that's powered-off.

 

 

If you considering a way to do four drives at once, you might want to find out how much memory each preclear shell is going to require. I seem to recall that it has a big memory footprint...

 

Not sure of the exact memory requirement; but I've often done 3-at-a-time with no problem.    Nothing larger than 4TB, however => the memory requirement is likely larger for 6 and 8TB units, so 2-at-a-time may be safer.    It really depends on how much memory is installed in the server, however => I doubt 4-at-a-time is a problem on any server with 16GB (or more).

 

 

... if I recall currectly, drives that are being precleared are not included in the array count so you could use version 5 in the unregistered mode to preclear four drives at once.  And the preclear script does exactly the same job on ver 5 and 6 so you can use a precleared disk from one version in the other.

 

True for v5.  In v6 all connected drives count; but there's no restriction imposed with Pro, so that's only an issue with Basic or Plus licenses.    The free version of v5, however, is an excellent choice for a "pre-clear system", as there's no 30-day Trial limit to be concerned with ... and, as noted, there's no restriction on the number of connected devices, so you could pre-clear as many drives as your system can handle at once.

 

[SSD]

The 6.0 licensing changes should not affect a preclearing system. You can have as many devices as you want so long as you never define/start an array. No need to even register for a trial license. 5.0 is also fine, but will not be around for long.

 

The size of a disk does not affect the memory footprint for preclearing.

 

Preclearing 4 at a time should be fine. Not sure I'd go much higher.

[Frank1940]

 

...

No need to even register for a trial license. 5.0 is also fine, but will not be around for long.

...

 

 

Well, I seem to recall that early in the discussion, about the time for beta1 for version 6, that LimeTech made some sort of commitment to keep ver 5 around for those folks whose hardware would/might have issues with ver 6.  (BTW, I know of one case where such conflict exists!  Whether it gets 'fixed' before 6.0.1 is released is an not an open issue at this time.)  So, I would suspect that it will  be available for downloading for some time after ver 6 finally goes final. 

 

In addition, ver5 will continue to ran just fine on all current (and older) hardware.  I was just reading a thread the other day posted by a user who was still running 4.3.3.  I would not want to be betting against seeing a thread five years from now from someone who has a problem with 5.0.4!

[SSD]

 

...

No need to even register for a trial license. 5.0 is also fine, but will not be around for long.

...

 

 

Well, I seem to recall that early in the discussion, about the time for beta1 for version 6, that LimeTech made some sort of commitment to keep ver 5 around for those folks whose hardware would/might have issues with ver 6.  (BTW, I know of one case where such conflict exists!  Whether it gets 'fixed' before 6.0.1 is released is an not an open issue at this time.)  So, I would suspect that it will  be available for downloading for some time after ver 6 finally goes final. 

 

In addition, ver5 will continue to ran just fine on all current (and older) hardware.  I was just reading a thread the other day posted by a user who was still running 4.3.3.  I would not want to be betting against seeing a thread five years from now from someone who has a problem with 5.0.4!

 

I was trying to make sure that people understand that the trial version of 6.0 CAN be used for preclearing. It is easy to confuse the licensing expiration and limits on the OS - but this is not the case. The limits are on STARTING AN UNRAID ARRAY. Since preclearing does not require an array at all, users should be able to freely use if for preclearing as many disks as they can simultaneously, and not require even the trial license key.

 

Version 5, as it is, may very well be around and be used for preclearing. And I expect if a user wanted a copy of any other older unRAID version, they could get it (there is a note on the unRAID download page to that affect). But I do not believe that version 5 will be seeing many if any additional updates after 6.0 goes final.  And as a result new hardware may not function properly, new controllers may not be supported. vulnerabilities may not get addresses, etc. etc.

 

 

[garycase]

Agree with both Brian and Frank => v5 will almost certainly not get any further updates;  but it will also be around for a long time 

 

... and can likely still be downloaded for some time to come, although I don't have any insight into just how long LimeTech will keep it available.

 

Note that there are quite a few folks who subscribe to the "If it ain't broke, don't fix it philosophy" and are still happily running v4.7 on servers that don't need > 2TB support.    I'm one of them      My main media server is still on v4.7, and will likely never be upgraded [i'll replace it at some point with newer hardware].    I also have two servers on v5 [My "everything except media" server and my backup server]  and one "test" server that's on v6.    I plan on building a new v6 server to replace the "everything but" server, but the media server is chugging along just fine.    FWIW, I'm pretty sure Joe L's server is also on v4.7.