worst fragmentation ever?

[browolf]

major whoops. Just discovered our backup server backup drive volume is 80%! fragmented.

 

thats a 1.6tb volume 73% used 591,193 files in 60,919 folders

 

trying to de-fragment it but it's slow going. it managed 2% overnight

[tech_guy]

YIKES!

[zag]

use a better defragger like diskkeeper.

[rvdmast]

don't bother, you'll spent days defragmenting, and one night of backup jobs later it'll be the same...and it really doesn't make restore/backup jobs, that take a lot of time anyway, much faster.

[Michael]

I presume you ran a checkdisk/scandisk first? Always important you do this!

[kmount]

Our backup exec box did this regularly, we found it to be to do with the size (we'd been using 50GB) disk back up files.

[FN-GM]

We defrag all our machines and servers daily to stop this. It doesn't take long at all when you keep ontop of it

[DAckroyd]

Put some SSD's into it and then defrag won't matter Edited November 6, 2009 by DAckroyd
missing a P

[mjs_mjs]

We have a scripted defrag here too, take a few seconds and keeps them relativly free from large fragments. Well worth setting up.

[matt40k]

Put some SSD's into it and then defrag won't matter

 

I wish this was cheap enough to be possible solution.

 

don't bother, you'll spent days defragmenting, and one night of backup jobs later it'll be the same...and it really doesn't make restore/backup jobs, that take a lot of time anyway, much faster.

 

Agreed.

 

Other idea, MOVE TO LINUX!

[plexer]

With the speed of todays processors, hard drives and the busses does fragmentation really matter?

 

Ben

[AyatollahPies]

With the speed of todays processors, hard drives and the busses does fragmentation really matter?

 

Ben

 

To steal a well known supermarket's slogan - "Every little helps"

[zag]

I wish this was cheap enough to be possible solution.

 

I've just put SSDs in my Sims and Profile servers. Massive improvement but time will tell on the reliability.

 

160gb Intel X-25M are about £300 these days, well worth the investment I reckon.

[matt40k]

For SIMS, yer £300 isn't bad. But for a backup server? Not yet.

[browolf]

With the speed of todays processors, hard drives and the busses does fragmentation really matter?

 

Ben

 

i cottoned on to it when it took a suspiciously long time to install some windows updates. the c: drive was like 40% fragmented too :-S

[tom_newton]

Still get fragmentation on Linux - just generally not as bad.

[rvdmast]

Quote:

Originally Posted by plexer View Post

With the speed of todays processors, hard drives and the busses does fragmentation really matter?

 

Ben

To steal a well known supermarket's slogan - "Every little helps"

 

So, would it really matter if your nightly backup job takes 2 hours 55 min. instaed of 3 hours because

your server spent half the day defragmenting?

 

On fileservers, yes, defragmenting might give you a slight performance gain that, in theory, benefits your users (although i doubt they'll notice).

On a backup-server, it's just not worth bothering, and believe me: i noticed the same fragmentation problem on our backup server and tried various defraggers.

[actuator]

There is a pdf on Zdnet that discusses backup performance and fragmentation...up to 30 % improvement for a defragged volume.

Improving Backup Performance with Defragmentation, from Diskeeper - White Papers, Webcasts and Case Studies - ZDNet

Mind you, it's a bit dated, but should still be relevant for magnetic HDD systems.

 

At the place I previously used to work part-time, they had the corporate versions of Diskeeper running on some servers. Worked very decently from what I could tell...automatic and all that.

[mjs_mjs]

With the speed of todays processors, hard drives and the busses does fragmentation really matter?

 

Ben

 

Yes, but not necessarily for speed reasons. If you think your actunator moves between tracks, every time it moves, some barings take a hit, which degrades them. So yes, a defraged drive decreases MTBF. which is never a good thing. Again, today it isn't so much of an issue because the life of the drive will almost everytime out live the machines usefullness time. They key to making a Hard drive last isn't the hardware but the software responsible for how it fills the drive. I've personally found that on windows, if you only let the drives fill to 50% then fragmentation doesn't matter (or occour). Also removing the virtual memory completely will speed up the access to the drive, and increase the life expectancy (in theroy). On linux, different file systems are different in how they fragment files. some will also defragment as and when they are idle.

[Teth]

Yea this comes down to types of fragmentation and the use of the drive. Not all fragmentation is a problem.

 

NTFS, EXT3+, Reiser, HFS all handle fragmentation well if left with 15-30% free space headroom.

 

Fragmentation is a single logical file stored in multiple non contiguous blocks and sectors on the physical disc. A modern file system like those listed above will always try to place a newly saved file in a continuous run of blocks. It is much faster to both read and write from a drive if the heads don't have to move.

 

The only time these file systems will fragment if kept above 30% free space is very large files and this isn't necessarily a problem. If a 700MB disc image gets split into 2, 5 or 10 sections it really doesn't matter. That will be read 200 blocks move hea,d read 200 more, repeat 3 more times. Its only when the seek to read ratio reaches a certain point that performance actually suffers.

 

There are of course like everything there are exceptions. A fragmented page file will badly hurt a machine's performance. Better defrag tools like diskkeeper and Norton defrag will arrange more frequently used files toward the center of the disk were seek times are faster due to the smaller circumfrence of the platter at that point so there are advantages to defragging.

 

In short. Daily defrag is causing disc wear for no real gain and your wasting time. Never defragging is a bad idea too.

 

I defrag machines after a build or any significant alteration of software and between terms. File servers I defrag every friday after school before backups.

 

Always scandisk before defragging. You don't want a defrag program moving data from good sectors into bad sectors which were not know and causing data loss.

[featured_spectre]

I have my servers defragging every day at 7pm. To defrag 1TB of data, takes roughly half hour all told, because it does it every day. After the defrag it backs up in around 2 mins as its incremental. Works a charm!

[plexer]

Yes, but not necessarily for speed reasons. If you think your actunator moves between tracks, every time it moves, some barings take a hit, which degrades them. So yes, a defraged drive decreases MTBF. which is never a good thing. Again, today it isn't so much of an issue because the life of the drive will almost everytime out live the machines usefullness time. They key to making a Hard drive last isn't the hardware but the software responsible for how it fills the drive. I've personally found that on windows, if you only let the drives fill to 50% then fragmentation doesn't matter (or occour). Also removing the virtual memory completely will speed up the access to the drive, and increase the life expectancy (in theroy). On linux, different file systems are different in how they fragment files. some will also defragment as and when they are idle.

 

Surely running a defrag adds additional read/writes as well which will cause the same issue?

 

Ben

[mjs_mjs]

Surely running a defrag adds additional read/writes as well which will cause the same issue?

 

Ben

 

Indeed it does. There is a balance to how often one should defrag. There is a biting point much like a car clutch as to when the best time to defrag is. It's the point at which the ware by the defrage will be less than continous ware of fragmented access. This is if you take i want my drives to last the longest approach, but more often than not we're after speed and performance which means you can aford to take a hit on MTBF of your drives.

 

I'm guessing most of us will have drives on servers in RAID arrays. What significant differances are there when defragging thoes and does hardware/software RAID make much differance to fragmentation?