Re: RAID? Was: PATA hard disks, anyone?

2018-03-29 Thread Chuck Guzis via cctalk
On 03/29/2018 03:48 PM, Alexander Schreiber via cctalk wrote: > Also, AFS is built around volumes (think "virtual disks") and you have > the concept of a r/w volume with (potentially) a pile of r/o volumes > snapshotted from it. So one thing I did was that every (r/w) volume > had a directory

Re: RAID? Was: PATA hard disks, anyone?

2018-03-29 Thread Alexander Schreiber via cctalk
On Wed, Mar 28, 2018 at 01:17:08PM -0400, Ethan via cctalk wrote: > > I know of no RAID setup that can save me >from stupid. > > I use rsync. I manually rsync the working disks to the backup disks every > week or two. Working disks have the shares to other hosts. If something > happens to that

Re: RAID? Was: PATA hard disks, anyone?

2018-03-29 Thread Alexander Schreiber via cctalk
1 PM (GMT-08:00) > > To: "General Discussion: On-Topic and Off-Topic Posts" > > <cctalk@classiccmp.org> > > Subject: RAID? Was: PATA hard disks, anyone? > > > > How many drives would you need, to be able to set up a RAID, or hot > &

Re: RAID? Was: PATA hard disks, anyone?

2018-03-29 Thread Peter Corlett via cctalk
On Wed, Mar 28, 2018 at 05:40:29PM -0700, Richard Pope via cctalk wrote: > I have been kind of following this thread. I have a question about MTBF. I > have four HGST UltraStar Enterprise 2TB drives setup in a Hardware RAID 10 > configuration. If the the MTBF is 100,000 Hrs for each drive does

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Paul Koning via cctalk
It's not quite that bad. The answer is that the MTBF of four drives is probably not simply the MTBF of one drive divided by four. If you have a good description of the probability of failure as a function of drive age (i.e., a picture of its particular "bathtub curve") you can then work out

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Richard Pope via cctalk
Fred, I appreciate the explanation. So with out a 1,000, 10,000, or even 100,000 drives there is no way to know how long my drives in the RAID will last. All I know for sure is that I can lose anyone drive and the RAID can be rebuilt. GOD Bless and Thanks, rich! On 3/28/2018 4:43 PM,

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Fred Cisin via cctalk
On Wed, 28 Mar 2018, Richard Pope via cctalk wrote: I have been kind of following this thread. I have a question about MTBF. I have four HGST UltraStar Enterprise 2TB drives setup in a Hardware RAID 10 configuration. If the the MTBF is 100,000 Hrs for each drive does this mean that the

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Richard Pope via cctalk
Hello all, I have been kind of following this thread. I have a question about MTBF. I have four HGST UltraStar Enterprise 2TB drives setup in a Hardware RAID 10 configuration. If the the MTBF is 100,000 Hrs for each drive does this mean that the total MTBF is 25,000 Hrs? GOD Bless and

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Grant Taylor via cctalk
On 03/28/2018 12:32 PM, Fred Cisin via cctalk wrote: With very unreliable drives, that isn't acceptable. If each "drive" within the RAID were itself a RAID, . . . Getting to be a complicated controller, or cascading controllers, . . . Many of the SCSI / SAS RAID controllers that I've worked

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Peter Corlett via cctalk
On Wed, Mar 28, 2018 at 09:33:38AM -0400, Paul Koning via cctalk wrote: [...] > The basic assumption is that failures are "fail stop", i.e., a drive refuses > to deliver data. (In particular, it doesn't lie -- deliver wrong data. You > can build systems that deal with lying drives but RAID is not

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Paul Koning via cctalk
> On Mar 28, 2018, at 2:32 PM, Fred Cisin via cctalk > wrote: > >>> How many drives would you need, to be able to set up a RAID, or hot >>> swappable RAUD (Redundant Array of Unreliable Drives), that could give >>> decent reliability with such drives? >>> How many to

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Fred Cisin via cctalk
How many drives would you need, to be able to set up a RAID, or hot swappable RAUD (Redundant Array of Unreliable Drives), that could give decent reliability with such drives? How many to be able to not have data loss if a second one dies before the first casualty is replaced? How many to be

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Chuck Guzis via cctalk
On 03/28/2018 10:17 AM, Ethan via cctalk wrote: >> I know of no RAID setup that can save me >from stupid. > > I use rsync. I manually rsync the working disks to the backup disks > every week or two. Working disks have the shares to other hosts. If > something happens to that data, deleted by

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Toby Thain via cctalk
On 2018-03-28 1:17 PM, Ethan via cctalk wrote: >> I know of no RAID setup that can save me >from stupid. > > I use rsync. I manually rsync the working disks to the backup disks > every week or two. Working disks have the shares to other hosts. If > something happens to that data, deleted by

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Grant Taylor via cctalk
On 03/28/2018 11:51 AM, David Brownlee via cctalk wrote: A step up from rsync can be dirvish - it uses rsync, but before each backup it creates a hardlink tree of the previous backup, then rsyncs over it. The net effect is you only pay the block cost of one copy of unchanged files, plus an

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Grant Taylor via cctalk
On 03/28/2018 11:17 AM, Paul Berger via cctalk wrote: You mean something like someone who writes a script that does blind cd to the directory and then proceeds to delete the contents? This is one of the primary reasons that I prefer to see the full path specified on the rm command. --

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread David Brownlee via cctalk
On 28 March 2018 at 18:17, Ethan via cctalk wrote: > I know of no RAID setup that can save me >from stupid. >> > > I use rsync. I manually rsync the working disks to the backup disks every > week or two. Working disks have the shares to other hosts. If something > happens

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Paul Berger via cctalk
On 2018-03-28 2:09 PM, Ali via cctalk wrote: Original message From: Chuck Guzis via cctalk <cctalk@classiccmp.org> Date: 3/28/18 10:02 AM (GMT-08:00) To: Paul Koning via cctalk <cctalk@classiccmp.org> Subject: Re: RAID? Was: PATA hard disks, anyo

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Ethan via cctalk
I know of no RAID setup that can save me >from stupid. I use rsync. I manually rsync the working disks to the backup disks every week or two. Working disks have the shares to other hosts. If something happens to that data, deleted by accident or encrypted by malware. Meh. Hardware like

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Ali via cctalk
Original message From: Chuck Guzis via cctalk <cctalk@classiccmp.org> Date: 3/28/18 10:02 AM (GMT-08:00) To: Paul Koning via cctalk <cctalk@classiccmp.org> Subject: Re: RAID? Was: PATA hard disks, anyone? >I know of no RAID setup that can save

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Chuck Guzis via cctalk
On 03/28/2018 06:33 AM, Paul Koning via cctalk wrote: > These are straightforward questions of probability math, but it takes > some time to get the details right. For one thing, you need > believable numbers for the underlying error probabilities. And you > have to analyze the cases carefully.

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Paul Koning via cctalk
> On Mar 27, 2018, at 8:51 PM, Fred Cisin via cctalk > wrote: > > Well outside my realm of expertise (as if I had a realm!), . . . > > How many drives would you need, to be able to set up a RAID, or hot swappable > RAUD (Redundant Array of Unreliable Drives), that

Re: RAID? Was: PATA hard disks, anyone?

2018-03-28 Thread Liam Proven via cctalk
On 28 March 2018 at 02:51, Fred Cisin via cctalk wrote: > Well outside my realm of expertise (as if I had a realm!), . . . > > How many drives would you need, to be able to set up a RAID, or hot > swappable RAUD (Redundant Array of Unreliable Drives), that could give >

Re: RAID? Was: PATA hard disks, anyone?

2018-03-27 Thread Paul Berger via cctalk
On 2018-03-27 10:05 PM, Ali via cctalk wrote: Original message From: Fred Cisin via cctalk <cctalk@classiccmp.org> Date: 3/27/18 5:51 PM (GMT-08:00) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> Subject: RAID

RE: RAID? Was: PATA hard disks, anyone?

2018-03-27 Thread Ali via cctalk
Original message From: Fred Cisin via cctalk <cctalk@classiccmp.org> Date: 3/27/18 5:51 PM (GMT-08:00) To: "General Discussion: On-Topic and Off-Topic Posts" <cctalk@classiccmp.org> Subject: RAID? Was: PATA hard disks, anyone? How many

RAID? Was: PATA hard disks, anyone?

2018-03-27 Thread Fred Cisin via cctalk
Well outside my realm of expertise (as if I had a realm!), . . . How many drives would you need, to be able to set up a RAID, or hot swappable RAUD (Redundant Array of Unreliable Drives), that could give decent reliability with such drives? How many to be able to not have data loss if a